Articles | Volume 18, issue 6
https://doi.org/10.5194/acp-18-4113-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Special issue:
https://doi.org/10.5194/acp-18-4113-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
26 Mar 2018
Research article |
| 26 Mar 2018
| 26 Mar 2018
Diurnal variation in middle-atmospheric ozone observed by ground-based microwave radiometry at Ny-Ålesund over 1 year
Franziska Schranz
CORRESPONDING AUTHOR
Institute of Applied Physics, University of Bern, Bern, Switzerland
Susana Fernandez
Department of Physics, University of Santiago de Chile, Santiago, Chile
Niklaus Kämpfer
Institute of Applied Physics, University of Bern, Bern, Switzerland
Mathias Palm
Institute of Environmental Physics, University of Bremen, Bremen, Germany
Related authors
Franziska Schranz, Jonas Hagen, Gunter Stober, Klemens Hocke, Axel Murk, and Niklaus Kämpfer
Atmos. Chem. Phys., 20, 10791–10806, https://doi.org/10.5194/acp-20-10791-2020, https://doi.org/10.5194/acp-20-10791-2020, 2020
Short summary
Short summary
We measured middle-atmospheric ozone, water vapour and zonal and meridional wind with two ground-based microwave radiometers which are located at Ny-Alesund, Svalbard, in the Arctic. In this article we present measurements of the small-scale horizontal ozone gradients during winter 2018/2019. We found a distinct seasonal variation of the ozone gradients which is linked to the planetary wave activity. We further present the signatures of the SSW in the ozone, water vapour and wind measurements.
Franziska Schranz, Brigitte Tschanz, Rolf Rüfenacht, Klemens Hocke, Mathias Palm, and Niklaus Kämpfer
Atmos. Chem. Phys., 19, 9927–9947, https://doi.org/10.5194/acp-19-9927-2019, https://doi.org/10.5194/acp-19-9927-2019, 2019
Short summary
Short summary
The dynamics of the Arctic middle atmosphere above Ny-Ålesund, Svalbard (79° N, 12° E) is investigated using 3 years of H2O and O3 measurements from ground-based microwave radiometers. We found the signals of atmospheric phenomena like sudden stratospheric warmings, polar vortex shifts, effective descent rates of water vapour and periodicities in our data. Additionally, a comprehensive intercomparison is performed with models and measurements from ground-based, in situ and satellite instruments.
Klemens Hocke, Jonas Hagen, Franziska Schranz, and Leonie Bernet
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-630, https://doi.org/10.5194/acp-2019-630, 2019
Preprint withdrawn
Short summary
Short summary
The dense sampling of geopotential height (GPH) profiles of the microwave limb sounder (MLS) on NASA's satellite Aura is appropriate for detection of mesospheric gravity waves. Up to now, the global distribution of mesospheric gravity wave activity is relatively unknown. The study focuses on the relation of mesospheric gravity waves to major sudden stratospheric warmings.
Rolf Rüfenacht, Gerd Baumgarten, Jens Hildebrand, Franziska Schranz, Vivien Matthias, Gunter Stober, Franz-Josef Lübken, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 1971–1987, https://doi.org/10.5194/amt-11-1971-2018, https://doi.org/10.5194/amt-11-1971-2018, 2018
Short summary
Short summary
Wind information throughout the middle-atmosphere is crucial for the understanding of atmospheric dynamics but became available only recently, thanks to developments in remote sensing and modelling approaches. We present the first thorough assessment of the quality of the wind estimates by comparing co-located observations from lidar and microwave radiometry and opposing them to the major atmospheric models. Moreover we evaluated a new approach for measuring mesopause region wind by radiometry.
Martin Lainer, Klemens Hocke, Rolf Rüfenacht, and Niklaus Kämpfer
Atmos. Chem. Phys., 17, 14905–14917, https://doi.org/10.5194/acp-17-14905-2017, https://doi.org/10.5194/acp-17-14905-2017, 2017
Short summary
Short summary
We report on middle-atmospheric water vapor measurements above Bern from the ground-based microwave radiometer MIAWARA (NDACC affiliated) during two winter periods of 6 months. Quasi 18 h oscillations of mesospheric water vapor above 0.1 hPa are observed. Further, the 18 h wave is seen in a zonal wind data set from the Doppler wind radiometer WIRA. Inertia-gravity-wave-induced fluctuations or a nonlinear coupling between tides and quasi 2-day waves are considered as possible drivers.
Francisco Navas-Guzmán, Niklaus Kämpfer, Franziska Schranz, Wolfgang Steinbrecht, and Alexander Haefele
Atmos. Chem. Phys., 17, 14085–14104, https://doi.org/10.5194/acp-17-14085-2017, https://doi.org/10.5194/acp-17-14085-2017, 2017
Short summary
Short summary
The paper presents assessment of the stratospheric measurements of a relatively new temperature radiometer (TEMPERA) at 60 GHz. The temperature profiles from TEMPERA have been compared with measurements from different techniques such as radiosondes, MLS satellite and Rayleigh lidar and with the temperature outputs from the SD-WACCM model. The results showed absolute biases and standard deviations lower than 2 K for most of the altitudes and comparisons, proving the good performance of TEMPERA.
Klemens Hocke, Franziska Schranz, Eliane Maillard Barras, Lorena Moreira, and Niklaus Kämpfer
Atmos. Chem. Phys., 17, 3445–3452, https://doi.org/10.5194/acp-17-3445-2017, https://doi.org/10.5194/acp-17-3445-2017, 2017
Short summary
Short summary
Observation and simulation show an Atlantic ozone streamer along the edge region of the polar vortex in the northern middle stratosphere during winter. The Atlantic streamer has wind speeds of about 100 m/s and turns equatorward at a vortex erosion region. We compare the fields of stratospheric ozone and water vapour from ground- and space-based microwave radiometry and SD-WACCM simulations for a better understanding of non-linear transport processes in the middle atmosphere.
Klemens Hocke, Martin Lainer, Lorena Moreira, Jonas Hagen, Susana Fernandez Vidal, and Franziska Schranz
Ann. Geophys., 34, 781–788, https://doi.org/10.5194/angeo-34-781-2016, https://doi.org/10.5194/angeo-34-781-2016, 2016
Short summary
Short summary
The dense horizontal sampling of atmospheric temperature profiles by the microwave limb sounder MLS on the NASA satellite AURA permit the estimation of global distributions of inertia-gravity waves (IGWs) in the middle atmosphere. We present and discuss the estimated global distributions of IGWs for July 2015 and January 2016. A dependence on the zonal wind distribution is obvious. The distributions of IGWs are a bit similar to the global distributions of small-scale gravity waves.
Denghui Ji, Mathias Palm, Matthias Buschmann, Kerstin Ebell, Marion Maturilli, Xiaoyu Sun, and Justus Notholt
EGUsphere, https://doi.org/10.5194/egusphere-2024-2241, https://doi.org/10.5194/egusphere-2024-2241, 2024
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Our study explores how certain aerosols, like sea salt, affect infrared heat radiation in the Arctic, potentially speeding up warming. We used advanced technology to measure aerosol composition and found that these particles grow with humidity, significantly increasing their heat-trapping effect in the infrared region, especially in winter. Our findings suggest these aerosols could be a key factor in Arctic warming, emphasizing the importance of understanding aerosols for climate prediction.
Jamal Makkor, Mathias Palm, Matthias Buschmann, Emmanuel Mahieu, Martyn P. Chipperfield, and Justus Notholt
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2024-93, https://doi.org/10.5194/amt-2024-93, 2024
Preprint under review for AMT
Short summary
Short summary
During the years 1950 and 1951, Marcel Migeotte took regular solar measurements in form of paper rolls at the Jungfraujoch site. These historical spectra proved valuable for atmospheric research and needed to be saved for posterity. Therefore, a digitization method which used image processing techniques was developed to extract them from the historical paper rolls. This allowed them to be saved in a machine-readable format that is easily accessible to the scientific community.
Kelley Wells, Dylan Millet, Jared Brewer, Vivienne Payne, Karen Cady-Pereira, Rick Pernak, Susan Kulawik, Corinne Vigouroux, Nicholas Jones, Emmanuel Mahieu, Maria Makarova, Tomoo Nagahama, Ivan Ortega, Mathias Palm, Kimberly Strong, Matthias Schneider, Dan Smale, Ralf Sussmann, and Minqiang Zhou
EGUsphere, https://doi.org/10.5194/egusphere-2024-1551, https://doi.org/10.5194/egusphere-2024-1551, 2024
Short summary
Short summary
Atmospheric volatile organic compounds affect both air quality and climate. Satellite measurements can help us to assess and predict their global impacts. We present new long-term (2012–2023) measurements of four key VOCs: methanol, ethene, ethyne, and hydrogen cyanide (HCN) from the Cross-track Infrared Sounder. The measurements reflect emissions from major forests, wildfires, and industry, and provide new information to advance understanding of these sources and their changes over time.
Victoria A. Flood, Kimberly Strong, Cynthia H. Whaley, Kaley A. Walker, Thomas Blumenstock, James W. Hannigan, Johan Mellqvist, Justus Notholt, Mathias Palm, Amelie N. Röhling, Stephen Arnold, Stephen Beagley, Rong-You Chien, Jesper Christensen, Makoto Deushi, Srdjan Dobricic, Xinyi Dong, Joshua S. Fu, Michael Gauss, Wanmin Gong, Joakim Langner, Kathy S. Law, Louis Marelle, Tatsuo Onishi, Naga Oshima, David A. Plummer, Luca Pozzoli, Jean-Christophe Raut, Manu A. Thomas, Svetlana Tsyro, and Steven Turnock
Atmos. Chem. Phys., 24, 1079–1118, https://doi.org/10.5194/acp-24-1079-2024, https://doi.org/10.5194/acp-24-1079-2024, 2024
Short summary
Short summary
It is important to understand the composition of the Arctic atmosphere and how it is changing. Atmospheric models provide simulations that can inform policy. This study examines simulations of CH4, CO, and O3 by 11 models. Model performance is assessed by comparing results matched in space and time to measurements from five high-latitude ground-based infrared spectrometers. This work finds that models generally underpredict the concentrations of these gases in the Arctic troposphere.
Xiaoyu Sun, Mathias Palm, Katrin Müller, Jonas Hachmeister, and Justus Notholt
Atmos. Chem. Phys., 23, 7075–7090, https://doi.org/10.5194/acp-23-7075-2023, https://doi.org/10.5194/acp-23-7075-2023, 2023
Short summary
Short summary
The tropical western Pacific (TWP) is an active interhemispheric transport region contributing significantly to the global climate. A method to determine the chemical equator was developed by model simulations of a virtual passive tracer to analyze transport in the tropics, with a focus on the TWP region. We compare the chemical equator with tropical rain belts and wind fields and obtain a vertical pattern of interhemispheric transport processes which shows tilt structure in certain seasons.
Denghui Ji, Mathias Palm, Christoph Ritter, Philipp Richter, Xiaoyu Sun, Matthias Buschmann, and Justus Notholt
Atmos. Meas. Tech., 16, 1865–1879, https://doi.org/10.5194/amt-16-1865-2023, https://doi.org/10.5194/amt-16-1865-2023, 2023
Short summary
Short summary
To measuring aerosol components, a Fourier transform infrared spectrometer (FTIS) and a lidar are operated in Ny-Ålesund, Spitsbergen (78° N, 11° E). Using the FTIS, a retrieval algorithm is developed for dust, sea salt, black carbon, and sulfate. The distribution of aerosols or clouds is provided by lidar and used as an indicator for aerosol or cloud retrieval with the FTS. Thus, a two-instrument joint-observation scheme is designed and is used on the data measured from 2019 to the present.
Philipp Richter, Mathias Palm, Christine Weinzierl, Hannes Griesche, Penny M. Rowe, and Justus Notholt
Earth Syst. Sci. Data, 14, 2767–2784, https://doi.org/10.5194/essd-14-2767-2022, https://doi.org/10.5194/essd-14-2767-2022, 2022
Short summary
Short summary
We present a dataset of cloud optical depths, effective radii and water paths from optically thin clouds observed in the Arctic around Svalbard. The data have been retrieved from infrared spectral radiance measured using a Fourier-transform infrared (FTIR) spectrometer. Besides a description of the measurements and retrieval technique, the data are put into context with results of corresponding measurements from microwave radiometer, lidar and cloud radar.
Youwen Sun, Hao Yin, Xiao Lu, Justus Notholt, Mathias Palm, Cheng Liu, Yuan Tian, and Bo Zheng
Atmos. Chem. Phys., 21, 18589–18608, https://doi.org/10.5194/acp-21-18589-2021, https://doi.org/10.5194/acp-21-18589-2021, 2021
Short summary
Short summary
This study uses high-resolution nested-grid GEOS-Chem simulation, the eXtreme Gradient Boosting (XGBoost) machine learning method, and the exposure–response relationship to determine the drivers and evaluate the health risks of the unexpected surface O3 enhancements over the Sichuan Basin in 2020. These unexpected O3 enhancements were induced by meteorological anomalies and caused dramatically high health risks.
Mahesh Kumar Sha, Bavo Langerock, Jean-François L. Blavier, Thomas Blumenstock, Tobias Borsdorff, Matthias Buschmann, Angelika Dehn, Martine De Mazière, Nicholas M. Deutscher, Dietrich G. Feist, Omaira E. García, David W. T. Griffith, Michel Grutter, James W. Hannigan, Frank Hase, Pauli Heikkinen, Christian Hermans, Laura T. Iraci, Pascal Jeseck, Nicholas Jones, Rigel Kivi, Nicolas Kumps, Jochen Landgraf, Alba Lorente, Emmanuel Mahieu, Maria V. Makarova, Johan Mellqvist, Jean-Marc Metzger, Isamu Morino, Tomoo Nagahama, Justus Notholt, Hirofumi Ohyama, Ivan Ortega, Mathias Palm, Christof Petri, David F. Pollard, Markus Rettinger, John Robinson, Sébastien Roche, Coleen M. Roehl, Amelie N. Röhling, Constantina Rousogenous, Matthias Schneider, Kei Shiomi, Dan Smale, Wolfgang Stremme, Kimberly Strong, Ralf Sussmann, Yao Té, Osamu Uchino, Voltaire A. Velazco, Corinne Vigouroux, Mihalis Vrekoussis, Pucai Wang, Thorsten Warneke, Tyler Wizenberg, Debra Wunch, Shoma Yamanouchi, Yang Yang, and Minqiang Zhou
Atmos. Meas. Tech., 14, 6249–6304, https://doi.org/10.5194/amt-14-6249-2021, https://doi.org/10.5194/amt-14-6249-2021, 2021
Short summary
Short summary
This paper presents, for the first time, Sentinel-5 Precursor methane and carbon monoxide validation results covering a period from November 2017 to September 2020. For this study, we used global TCCON and NDACC-IRWG network data covering a wide range of atmospheric and surface conditions across different terrains. We also show the influence of a priori alignment, smoothing uncertainties and the sensitivity of the validation results towards the application of advanced co-location criteria.
Youwen Sun, Hao Yin, Cheng Liu, Emmanuel Mahieu, Justus Notholt, Yao Té, Xiao Lu, Mathias Palm, Wei Wang, Changgong Shan, Qihou Hu, Min Qin, Yuan Tian, and Bo Zheng
Atmos. Chem. Phys., 21, 11759–11779, https://doi.org/10.5194/acp-21-11759-2021, https://doi.org/10.5194/acp-21-11759-2021, 2021
Short summary
Short summary
The variability, sources, and transport of ethane (C2H6) over eastern China from 2015 to 2020 were studied using ground-based Fourier transform infrared (FTIR) spectroscopy and GEOS-Chem simulations. C2H6 variability is driven by both meteorological and emission factors. The reduction in C2H6 in recent years over eastern China points to air quality improvement in China.
Youwen Sun, Hao Yin, Cheng Liu, Lin Zhang, Yuan Cheng, Mathias Palm, Justus Notholt, Xiao Lu, Corinne Vigouroux, Bo Zheng, Wei Wang, Nicholas Jones, Changong Shan, Min Qin, Yuan Tian, Qihou Hu, Fanhao Meng, and Jianguo Liu
Atmos. Chem. Phys., 21, 6365–6387, https://doi.org/10.5194/acp-21-6365-2021, https://doi.org/10.5194/acp-21-6365-2021, 2021
Short summary
Short summary
This study mapped the drivers of HCHO variability from 2015 to 2019 over eastern China. Hydroxyl (OH) radical production rates from HCHO photolysis were evaluated. The relative contributions of emitted and photochemical sources to the observed HCHO abundance were analyzed. Contributions of various emission sources and geographical regions to the observed HCHO summertime enhancements were determined.
Thomas Blumenstock, Frank Hase, Axel Keens, Denis Czurlok, Orfeo Colebatch, Omaira Garcia, David W. T. Griffith, Michel Grutter, James W. Hannigan, Pauli Heikkinen, Pascal Jeseck, Nicholas Jones, Rigel Kivi, Erik Lutsch, Maria Makarova, Hamud K. Imhasin, Johan Mellqvist, Isamu Morino, Tomoo Nagahama, Justus Notholt, Ivan Ortega, Mathias Palm, Uwe Raffalski, Markus Rettinger, John Robinson, Matthias Schneider, Christian Servais, Dan Smale, Wolfgang Stremme, Kimberly Strong, Ralf Sussmann, Yao Té, and Voltaire A. Velazco
Atmos. Meas. Tech., 14, 1239–1252, https://doi.org/10.5194/amt-14-1239-2021, https://doi.org/10.5194/amt-14-1239-2021, 2021
Short summary
Short summary
This study investigates the level of channeling (optical resonances) of each FTIR spectrometer within the Network for the Detection of Atmospheric Composition Change (NDACC). Since the air gap of the beam splitter is a significant source of channeling, we propose new beam splitters with an increased wedge of the air gap. This study shows the potential for reducing channeling in the FTIR spectrometers operated by the NDACC, thereby increasing the quality of recorded spectra across the network.
Erik Lutsch, Kimberly Strong, Dylan B. A. Jones, Thomas Blumenstock, Stephanie Conway, Jenny A. Fisher, James W. Hannigan, Frank Hase, Yasuko Kasai, Emmanuel Mahieu, Maria Makarova, Isamu Morino, Tomoo Nagahama, Justus Notholt, Ivan Ortega, Mathias Palm, Anatoly V. Poberovskii, Ralf Sussmann, and Thorsten Warneke
Atmos. Chem. Phys., 20, 12813–12851, https://doi.org/10.5194/acp-20-12813-2020, https://doi.org/10.5194/acp-20-12813-2020, 2020
Short summary
Short summary
This paper describes the use of a network of 10 Arctic and midlatitude ground-based FTIR measurement sites to detect enhancements of the wildfire tracers carbon monoxide, hydrogen cyanide, and ethane from 2003 to 2018. A tagged CO GEOS-Chem simulation is used for source attribution and to evaluate the relative contribution of CO sources to the FTIR measurements. The use of FTIR measurements allowed for the emission ratios of hydrogen cyanide and ethane to be quantified.
Leonie Bernet, Elmar Brockmann, Thomas von Clarmann, Niklaus Kämpfer, Emmanuel Mahieu, Christian Mätzler, Gunter Stober, and Klemens Hocke
Atmos. Chem. Phys., 20, 11223–11244, https://doi.org/10.5194/acp-20-11223-2020, https://doi.org/10.5194/acp-20-11223-2020, 2020
Short summary
Short summary
With global warming, water vapour increases in the atmosphere. Water vapour is an important gas because it is a natural greenhouse gas and affects the formation of clouds, rain and snow. How much water vapour increases can vary in different regions of the world. To verify if it increases as expected on a regional scale, we analysed water vapour measurements in Switzerland. We found that water vapour generally increases as expected from temperature changes, except in winter.
Franziska Schranz, Jonas Hagen, Gunter Stober, Klemens Hocke, Axel Murk, and Niklaus Kämpfer
Atmos. Chem. Phys., 20, 10791–10806, https://doi.org/10.5194/acp-20-10791-2020, https://doi.org/10.5194/acp-20-10791-2020, 2020
Short summary
Short summary
We measured middle-atmospheric ozone, water vapour and zonal and meridional wind with two ground-based microwave radiometers which are located at Ny-Alesund, Svalbard, in the Arctic. In this article we present measurements of the small-scale horizontal ozone gradients during winter 2018/2019. We found a distinct seasonal variation of the ozone gradients which is linked to the planetary wave activity. We further present the signatures of the SSW in the ozone, water vapour and wind measurements.
Eliane Maillard Barras, Alexander Haefele, Liliane Nguyen, Fiona Tummon, William T. Ball, Eugene V. Rozanov, Rolf Rüfenacht, Klemens Hocke, Leonie Bernet, Niklaus Kämpfer, Gerald Nedoluha, and Ian Boyd
Atmos. Chem. Phys., 20, 8453–8471, https://doi.org/10.5194/acp-20-8453-2020, https://doi.org/10.5194/acp-20-8453-2020, 2020
Short summary
Short summary
To determine the part of the variability of the long-term ozone profile trends coming from measurement timing, we estimate microwave radiometer trends for each hour of the day with a multiple linear regression model. The variation in the trend with local solar time is not significant at the 95 % confidence level either in the stratosphere or in the low mesosphere. We conclude that systematic sampling differences between instruments cannot explain significant differences in trend estimates.
Philipp Richter, Mathias Palm, Christine Weinzierl, Hannes Griesche, Penny M. Rowe, and Justus Notholt
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2020-266, https://doi.org/10.5194/amt-2020-266, 2020
Preprint withdrawn
Short summary
Short summary
Optically thin clouds containing low amounts of water are difficult to observe, but due to their frequent presence they have a non-neglectible impact on Earth's radiative budget. Here we present a retrieval for mixed-phase clouds from thermal-infared spectra, measured using a FTIR spectrometer. Even in situations where the atmospheric windows in the far-infrared are not applicable, cloud optical depths, effective droplet radii and water paths of mixed-phase clouds can be retrieved.
Corinne Vigouroux, Bavo Langerock, Carlos Augusto Bauer Aquino, Thomas Blumenstock, Zhibin Cheng, Martine De Mazière, Isabelle De Smedt, Michel Grutter, James W. Hannigan, Nicholas Jones, Rigel Kivi, Diego Loyola, Erik Lutsch, Emmanuel Mahieu, Maria Makarova, Jean-Marc Metzger, Isamu Morino, Isao Murata, Tomoo Nagahama, Justus Notholt, Ivan Ortega, Mathias Palm, Gaia Pinardi, Amelie Röhling, Dan Smale, Wolfgang Stremme, Kim Strong, Ralf Sussmann, Yao Té, Michel van Roozendael, Pucai Wang, and Holger Winkler
Atmos. Meas. Tech., 13, 3751–3767, https://doi.org/10.5194/amt-13-3751-2020, https://doi.org/10.5194/amt-13-3751-2020, 2020
Short summary
Short summary
We validate the TROPOMI HCHO product with ground-based FTIR (Fourier-transform infrared) measurements from 25 stations. We find that TROPOMI overestimates HCHO under clean conditions, while it underestimates it at high HCHO levels. Both TROPOMI precision and accuracy reach the pre-launch requirements, and its precision can even be 2 times better. The observed TROPOMI seasonal variability is in agreement with the FTIR data. The TROPOMI random uncertainty and data filtering should be refined.
Youwen Sun, Cheng Liu, Lin Zhang, Mathias Palm, Justus Notholt, Hao Yin, Corinne Vigouroux, Erik Lutsch, Wei Wang, Changong Shan, Thomas Blumenstock, Tomoo Nagahama, Isamu Morino, Emmanuel Mahieu, Kimberly Strong, Bavo Langerock, Martine De Mazière, Qihou Hu, Huifang Zhang, Christof Petri, and Jianguo Liu
Atmos. Chem. Phys., 20, 5437–5456, https://doi.org/10.5194/acp-20-5437-2020, https://doi.org/10.5194/acp-20-5437-2020, 2020
Short summary
Short summary
We present multiyear time series of ground-based Fourier-transform infrared spectroscopy measurements of HCN in densely populated eastern China. The seasonality and interannual variability of tropospheric HCN columns were investigated. The potential sources that drive the observed HCN seasonality and interannual variability were determined using a GEOS-Chem tagged CO simulation, global fire maps, and potential source contribution function values calculated using HYSPLIT back trajectories.
Jonas Hagen, Klemens Hocke, Gunter Stober, Simon Pfreundschuh, Axel Murk, and Niklaus Kämpfer
Atmos. Chem. Phys., 20, 2367–2386, https://doi.org/10.5194/acp-20-2367-2020, https://doi.org/10.5194/acp-20-2367-2020, 2020
Short summary
Short summary
The middle atmosphere (30 to 70 km altitude) is stratified and, despite very strong horizontal winds, there is less mixing between the horizontal layers. An important driver for the energy exchange between the layers in this regime is atmospheric tides, which are waves that are driven by the diurnal cycle of solar heating. We measure these tides in the wind field for the first time using a ground-based passive instrument. Ultimately, such measurements could be used to improve atmospheric models.
Christine Aebi, Julian Gröbner, Stelios Kazadzis, Laurent Vuilleumier, Antonis Gkikas, and Niklaus Kämpfer
Atmos. Meas. Tech., 13, 907–923, https://doi.org/10.5194/amt-13-907-2020, https://doi.org/10.5194/amt-13-907-2020, 2020
Short summary
Short summary
Clouds are one of the largest sources of uncertainties in climate models. The current study estimates the cloud optical thickness (COT), the effective droplet radius and the single scattering albedo of stratus–altostratus and cirrus–cirrostratus clouds in Payerne, Switzerland, by combining ground- and satellite-based measurements and radiative transfer models. The estimated values are thereafter compared with data retrieved from other methods. The mean COT is distinct for different seasons.
Minqiang Zhou, Bavo Langerock, Corinne Vigouroux, Mahesh Kumar Sha, Christian Hermans, Jean-Marc Metzger, Huilin Chen, Michel Ramonet, Rigel Kivi, Pauli Heikkinen, Dan Smale, David F. Pollard, Nicholas Jones, Voltaire A. Velazco, Omaira E. García, Matthias Schneider, Mathias Palm, Thorsten Warneke, and Martine De Mazière
Atmos. Meas. Tech., 12, 5979–5995, https://doi.org/10.5194/amt-12-5979-2019, https://doi.org/10.5194/amt-12-5979-2019, 2019
Short summary
Short summary
The differences between the TCCON and NDACC XCO measurements are investigated and discussed based on six NDACC–TCCON sites (Ny-Ålesund, Bremen, Izaña, Saint-Denis, Wollongong and Lauder) using data over the period 2007–2017. The smoothing errors from both TCCON and NDACC measurements are estimated. In addition, the scaling factor of the TCCON XCO data is reassessed by comparing with the AirCore measurements at Sodankylä and Orléans.
Franziska Schranz, Brigitte Tschanz, Rolf Rüfenacht, Klemens Hocke, Mathias Palm, and Niklaus Kämpfer
Atmos. Chem. Phys., 19, 9927–9947, https://doi.org/10.5194/acp-19-9927-2019, https://doi.org/10.5194/acp-19-9927-2019, 2019
Short summary
Short summary
The dynamics of the Arctic middle atmosphere above Ny-Ålesund, Svalbard (79° N, 12° E) is investigated using 3 years of H2O and O3 measurements from ground-based microwave radiometers. We found the signals of atmospheric phenomena like sudden stratospheric warmings, polar vortex shifts, effective descent rates of water vapour and periodicities in our data. Additionally, a comprehensive intercomparison is performed with models and measurements from ground-based, in situ and satellite instruments.
Klemens Hocke, Jonas Hagen, Franziska Schranz, and Leonie Bernet
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2019-630, https://doi.org/10.5194/acp-2019-630, 2019
Preprint withdrawn
Short summary
Short summary
The dense sampling of geopotential height (GPH) profiles of the microwave limb sounder (MLS) on NASA's satellite Aura is appropriate for detection of mesospheric gravity waves. Up to now, the global distribution of mesospheric gravity wave activity is relatively unknown. The study focuses on the relation of mesospheric gravity waves to major sudden stratospheric warmings.
Niall J. Ryan, Mathias Palm, Christoph G. Hoffmann, Jens Goliasch, and Justus Notholt
Atmos. Meas. Tech., 12, 4077–4089, https://doi.org/10.5194/amt-12-4077-2019, https://doi.org/10.5194/amt-12-4077-2019, 2019
Short summary
Short summary
We present a new ground-based instrument (CORAM) that measures atmospheric carbon monoxide (CO) concentrations within approximately 47–87 km in altitude with a 1 h time resolution. The measurements are made at Ny-Ålesund (79° N), Svalbard, and add much-needed coverage to the high Arctic. The first measured CO profiles from winter 2017/2018 are compared to co-located measurements from the Aura MLS satellite instrument and show agreement on daily and monthly timescales.
Martin Lainer, Klemens Hocke, Ellen Eckert, and Niklaus Kämpfer
Atmos. Chem. Phys., 19, 6611–6620, https://doi.org/10.5194/acp-19-6611-2019, https://doi.org/10.5194/acp-19-6611-2019, 2019
Short summary
Short summary
A middle atmospheric water vapor time series of more than 11 years (April 2007 to May 2018) from the NDACC microwave remote sensing site at Bern (Switzerland) is investigated to estimate the trend by means of a robust multilinear parametric trend model. Between 61 and 72 km altitude a significant decline in water vapor could be detected. The reduction of water vapor maximizes to about −12 % per decade at 72 km altitude.
Leonie Bernet, Thomas von Clarmann, Sophie Godin-Beekmann, Gérard Ancellet, Eliane Maillard Barras, René Stübi, Wolfgang Steinbrecht, Niklaus Kämpfer, and Klemens Hocke
Atmos. Chem. Phys., 19, 4289–4309, https://doi.org/10.5194/acp-19-4289-2019, https://doi.org/10.5194/acp-19-4289-2019, 2019
Short summary
Short summary
After severe ozone depletion, upper stratospheric ozone has started to recover in recent years. However, stratospheric ozone trends from various data sets still show differences. To partly explain such differences, we investigate how the trends are affected by different factors, for example, anomalies in the data. We show how trend estimates can be improved by considering such anomalies and present updated stratospheric ozone trends from ground data measured in central Europe.
Minqiang Zhou, Bavo Langerock, Kelley C. Wells, Dylan B. Millet, Corinne Vigouroux, Mahesh Kumar Sha, Christian Hermans, Jean-Marc Metzger, Rigel Kivi, Pauli Heikkinen, Dan Smale, David F. Pollard, Nicholas Jones, Nicholas M. Deutscher, Thomas Blumenstock, Matthias Schneider, Mathias Palm, Justus Notholt, James W. Hannigan, and Martine De Mazière
Atmos. Meas. Tech., 12, 1393–1408, https://doi.org/10.5194/amt-12-1393-2019, https://doi.org/10.5194/amt-12-1393-2019, 2019
Short summary
Short summary
N2O is an important atmospheric gas which is observed by two ground-based FTIR networks (TCCON and NDACC). The difference between NDACC and TCCON XN2O measurements is discussed. It is found that the bias between the two networks is within their combined uncertainties. However, TCCON measurements are affected by a priori profiles. In addition, the TCCON and NDACC N2O measurements are compared with the GEOS-Chem model simulations.
Christine Aebi, Julian Gröbner, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 5549–5563, https://doi.org/10.5194/amt-11-5549-2018, https://doi.org/10.5194/amt-11-5549-2018, 2018
Short summary
Short summary
A newly developed hemispherical thermal infrared cloud camera (IRCCAM) is presented. The IRCCAM allows automatic cloud detection during the day and at night-time. The cloud fraction determined from the IRCCAM is compared with the cloud fraction determined from other instruments over a time period of 2 years. The IRCCAM has an agreement of +/- 2 oktas cloud fraction in 90 % of the data compared to other instruments. There are no significant differences between seasons or different times of day.
Youwen Sun, Cheng Liu, Mathias Palm, Corinne Vigouroux, Justus Notholt, Qihou Hu, Nicholas Jones, Wei Wang, Wenjing Su, Wenqiang Zhang, Changong Shan, Yuan Tian, Xingwei Xu, Martine De Mazière, Minqiang Zhou, and Jianguo Liu
Atmos. Chem. Phys., 18, 14569–14583, https://doi.org/10.5194/acp-18-14569-2018, https://doi.org/10.5194/acp-18-14569-2018, 2018
Short summary
Short summary
The seasonal evolution of O3 and its photochemical production regime in a polluted region of eastern China between 2014 and 2017 was investigated using FTS observations. We observed a broad summer O3 maximum in Hefei, China, and the ozone production is mainly NOx limited in spring and summer and is mainly VOC or mixed VOC–NOx limited in autumn and winter.
Minqiang Zhou, Bavo Langerock, Corinne Vigouroux, Mahesh Kumar Sha, Michel Ramonet, Marc Delmotte, Emmanuel Mahieu, Whitney Bader, Christian Hermans, Nicolas Kumps, Jean-Marc Metzger, Valentin Duflot, Zhiting Wang, Mathias Palm, and Martine De Mazière
Atmos. Chem. Phys., 18, 13881–13901, https://doi.org/10.5194/acp-18-13881-2018, https://doi.org/10.5194/acp-18-13881-2018, 2018
Short summary
Short summary
This study focuses on atmospheric CO and CH4 time series and seasonal variations on Reunion Island based on in situ and FTIR measurements from two sites, Saint Denis and Maido. Ground-based in situ and FTIR (NDACC and TCCON) measurements are used to show their complementarity with regards to obtaining the CO and CH4 concentrations at the surface and in the troposphere and stratosphere. FLEXPART and GEOS-Chem models are applied to understand the seasonal variations of CO and CH4 at this site.
Corinne Vigouroux, Carlos Augusto Bauer Aquino, Maite Bauwens, Cornelis Becker, Thomas Blumenstock, Martine De Mazière, Omaira García, Michel Grutter, César Guarin, James Hannigan, Frank Hase, Nicholas Jones, Rigel Kivi, Dmitry Koshelev, Bavo Langerock, Erik Lutsch, Maria Makarova, Jean-Marc Metzger, Jean-François Müller, Justus Notholt, Ivan Ortega, Mathias Palm, Clare Paton-Walsh, Anatoly Poberovskii, Markus Rettinger, John Robinson, Dan Smale, Trissevgeni Stavrakou, Wolfgang Stremme, Kim Strong, Ralf Sussmann, Yao Té, and Geoffrey Toon
Atmos. Meas. Tech., 11, 5049–5073, https://doi.org/10.5194/amt-11-5049-2018, https://doi.org/10.5194/amt-11-5049-2018, 2018
Short summary
Short summary
A few ground-based stations have provided time series of HCHO columns until now, which was not optimal for providing good diagnostics for satellite or model validation. In this work, HCHO time series have been determined in a harmonized way at 21 stations ensuring, in addition to a better spatial and level of abundances coverage, that internal biases within the network have been minimized. This data set shows consistent good agreement with model data and is ready for future satellite validation.
Jonas Hagen, Axel Murk, Rolf Rüfenacht, Sergey Khaykin, Alain Hauchecorne, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 5007–5024, https://doi.org/10.5194/amt-11-5007-2018, https://doi.org/10.5194/amt-11-5007-2018, 2018
Martin Lainer, Klemens Hocke, and Niklaus Kämpfer
Atmos. Chem. Phys., 18, 12061–12074, https://doi.org/10.5194/acp-18-12061-2018, https://doi.org/10.5194/acp-18-12061-2018, 2018
Short summary
Short summary
A long continuous record (in total 7 years) of middle atmospheric water vapor at the midlatitude NDACC station in Bern is investigated to study quasi 2-day wave oscillations (Q2DWs). We present monthly climatologies of the wave amplitudes and show the periods that the Q2DWs developed. What we observe is very-high-frequency variability. An autobicoherence analysis revealed nonlinear phase couplings between Q2DWs and other atmospheric waves. Our results are useful for model validation purposes.
Youwen Sun, Mathias Palm, Cheng Liu, Frank Hase, David Griffith, Christine Weinzierl, Christof Petri, Wei Wang, and Justus Notholt
Atmos. Meas. Tech., 11, 2879–2896, https://doi.org/10.5194/amt-11-2879-2018, https://doi.org/10.5194/amt-11-2879-2018, 2018
Short summary
Short summary
We simulated instrumental line shape (ILS) degradations with respect to typical types of misalignment, and compared their influence on each NDACC gas. The requirements to suppress the ILS-degradation-related biases within a specified accuracy for all NDACC gases were deduced.
Rolf Rüfenacht, Gerd Baumgarten, Jens Hildebrand, Franziska Schranz, Vivien Matthias, Gunter Stober, Franz-Josef Lübken, and Niklaus Kämpfer
Atmos. Meas. Tech., 11, 1971–1987, https://doi.org/10.5194/amt-11-1971-2018, https://doi.org/10.5194/amt-11-1971-2018, 2018
Short summary
Short summary
Wind information throughout the middle-atmosphere is crucial for the understanding of atmospheric dynamics but became available only recently, thanks to developments in remote sensing and modelling approaches. We present the first thorough assessment of the quality of the wind estimates by comparing co-located observations from lidar and microwave radiometry and opposing them to the major atmospheric models. Moreover we evaluated a new approach for measuring mesopause region wind by radiometry.
Niall J. Ryan, Douglas E. Kinnison, Rolando R. Garcia, Christoph G. Hoffmann, Mathias Palm, Uwe Raffalski, and Justus Notholt
Atmos. Chem. Phys., 18, 1457–1474, https://doi.org/10.5194/acp-18-1457-2018, https://doi.org/10.5194/acp-18-1457-2018, 2018
Short summary
Short summary
We used model output and instrument data to assess how well polar atmospheric descent rates can be derived using concentration measurements of long-lived gases in the atmosphere. The results indicate that the method incurs errors as large as the descent rates, and often leads to a misinterpretation of the direction of air motion. The rates derived using this method do not appear to represent the mean vertical wind in the middle atmosphere, and we suggest an alternate definition.
Martin Lainer, Klemens Hocke, Rolf Rüfenacht, and Niklaus Kämpfer
Atmos. Chem. Phys., 17, 14905–14917, https://doi.org/10.5194/acp-17-14905-2017, https://doi.org/10.5194/acp-17-14905-2017, 2017
Short summary
Short summary
We report on middle-atmospheric water vapor measurements above Bern from the ground-based microwave radiometer MIAWARA (NDACC affiliated) during two winter periods of 6 months. Quasi 18 h oscillations of mesospheric water vapor above 0.1 hPa are observed. Further, the 18 h wave is seen in a zonal wind data set from the Doppler wind radiometer WIRA. Inertia-gravity-wave-induced fluctuations or a nonlinear coupling between tides and quasi 2-day waves are considered as possible drivers.
Gerald E. Nedoluha, Michael Kiefer, Stefan Lossow, R. Michael Gomez, Niklaus Kämpfer, Martin Lainer, Peter Forkman, Ole Martin Christensen, Jung Jin Oh, Paul Hartogh, John Anderson, Klaus Bramstedt, Bianca M. Dinelli, Maya Garcia-Comas, Mark Hervig, Donal Murtagh, Piera Raspollini, William G. Read, Karen Rosenlof, Gabriele P. Stiller, and Kaley A. Walker
Atmos. Chem. Phys., 17, 14543–14558, https://doi.org/10.5194/acp-17-14543-2017, https://doi.org/10.5194/acp-17-14543-2017, 2017
Short summary
Short summary
As part of the second SPARC (Stratosphere–troposphere Processes And their Role in Climate) water vapor assessment (WAVAS-II), we present measurements taken from or coincident with seven sites from which ground-based microwave instruments measure water vapor in the middle atmosphere. In the lower mesosphere, we quantify instrumental differences in the observed trends and annual variations at six sites. We then present a range of observed trends in water vapor over the past 20 years.
Christine Aebi, Julian Gröbner, Niklaus Kämpfer, and Laurent Vuilleumier
Atmos. Meas. Tech., 10, 4587–4600, https://doi.org/10.5194/amt-10-4587-2017, https://doi.org/10.5194/amt-10-4587-2017, 2017
Short summary
Short summary
The current study analyses the cloud radiative effect during the daytime depending on cloud fraction and cloud type at two stations in Switzerland over a time period of 3–5 years. Information about fractional cloud coverage and cloud type is retrieved from images taken by visible all-sky cameras. Cloud cover, cloud type and other atmospheric parameters have an influence on the magnitude of the longwave cloud effect as well as on the shortwave.
Francisco Navas-Guzmán, Niklaus Kämpfer, Franziska Schranz, Wolfgang Steinbrecht, and Alexander Haefele
Atmos. Chem. Phys., 17, 14085–14104, https://doi.org/10.5194/acp-17-14085-2017, https://doi.org/10.5194/acp-17-14085-2017, 2017
Short summary
Short summary
The paper presents assessment of the stratospheric measurements of a relatively new temperature radiometer (TEMPERA) at 60 GHz. The temperature profiles from TEMPERA have been compared with measurements from different techniques such as radiosondes, MLS satellite and Rayleigh lidar and with the temperature outputs from the SD-WACCM model. The results showed absolute biases and standard deviations lower than 2 K for most of the altitudes and comparisons, proving the good performance of TEMPERA.
Leonie Bernet, Francisco Navas-Guzmán, and Niklaus Kämpfer
Atmos. Meas. Tech., 10, 4421–4437, https://doi.org/10.5194/amt-10-4421-2017, https://doi.org/10.5194/amt-10-4421-2017, 2017
Short summary
Short summary
Microwave radiometry is a suitable technique to measure atmospheric temperature profiles during clear sky and cloudy conditions. However clouds can influence the temperature measurements. In this study we analyse the influence of clouds on temperature measurements in the troposphere from a microwave radiometer. We found that the effect of clouds on the temperature measurements is important and that the measurements can be improved substantially by considering clouds in the retrieval process.
Nils Hase, Scot M. Miller, Peter Maaß, Justus Notholt, Mathias Palm, and Thorsten Warneke
Geosci. Model Dev., 10, 3695–3713, https://doi.org/10.5194/gmd-10-3695-2017, https://doi.org/10.5194/gmd-10-3695-2017, 2017
Short summary
Short summary
Inverse modeling uses atmospheric measurements to estimate emissions of greenhouse gases, which are key to understand the climate system. However, the measurement information alone is typically insufficient to provide reasonable emission estimates. Additional information is required. This article applies modern mathematical inversion techniques to formulate such additional knowledge. It is a prime example of how such tools can improve the quality of estimates compared to commonly used methods.
Wolfgang Steinbrecht, Lucien Froidevaux, Ryan Fuller, Ray Wang, John Anderson, Chris Roth, Adam Bourassa, Doug Degenstein, Robert Damadeo, Joe Zawodny, Stacey Frith, Richard McPeters, Pawan Bhartia, Jeannette Wild, Craig Long, Sean Davis, Karen Rosenlof, Viktoria Sofieva, Kaley Walker, Nabiz Rahpoe, Alexei Rozanov, Mark Weber, Alexandra Laeng, Thomas von Clarmann, Gabriele Stiller, Natalya Kramarova, Sophie Godin-Beekmann, Thierry Leblanc, Richard Querel, Daan Swart, Ian Boyd, Klemens Hocke, Niklaus Kämpfer, Eliane Maillard Barras, Lorena Moreira, Gerald Nedoluha, Corinne Vigouroux, Thomas Blumenstock, Matthias Schneider, Omaira García, Nicholas Jones, Emmanuel Mahieu, Dan Smale, Michael Kotkamp, John Robinson, Irina Petropavlovskikh, Neil Harris, Birgit Hassler, Daan Hubert, and Fiona Tummon
Atmos. Chem. Phys., 17, 10675–10690, https://doi.org/10.5194/acp-17-10675-2017, https://doi.org/10.5194/acp-17-10675-2017, 2017
Short summary
Short summary
Thanks to the 1987 Montreal Protocol and its amendments, ozone-depleting chlorine (and bromine) in the stratosphere has declined slowly since the late 1990s. Improved and extended long-term ozone profile observations from satellites and ground-based stations confirm that ozone is responding as expected and has increased by about 2 % per decade since 2000 in the upper stratosphere, around 40 km altitude. At lower altitudes, however, ozone has not changed significantly since 2000.
Lorena Moreira, Klemens Hocke, and Niklaus Kämpfer
Atmos. Chem. Phys., 17, 10259–10268, https://doi.org/10.5194/acp-17-10259-2017, https://doi.org/10.5194/acp-17-10259-2017, 2017
Short summary
Short summary
GROMOS (GROund-based Millimeter-wave Ozone Spectrometer) has provided ozone profiles for the Network for the Detection of Atmospheric Composition Change since 1994. A new retrieval version for ozone profiles aims to improve the altitude range of profiles. We performed a comparison between coincident profiles of GROMOS and Aura MLS, resulting in agreement within 2% in
the mid- and upper stratosphere from 2009 to 2016. We also observed extensions of the tertiary ozone maximum at midlatitudes.
Enrico Dammers, Mark W. Shephard, Mathias Palm, Karen Cady-Pereira, Shannon Capps, Erik Lutsch, Kim Strong, James W. Hannigan, Ivan Ortega, Geoffrey C. Toon, Wolfgang Stremme, Michel Grutter, Nicholas Jones, Dan Smale, Jacob Siemons, Kevin Hrpcek, Denis Tremblay, Martijn Schaap, Justus Notholt, and Jan Willem Erisman
Atmos. Meas. Tech., 10, 2645–2667, https://doi.org/10.5194/amt-10-2645-2017, https://doi.org/10.5194/amt-10-2645-2017, 2017
Short summary
Short summary
Presented here is the validation of the CrIS fast physical retrieval (CFPR) NH3 column and profile measurements using ground-based Fourier transform infrared (FTIR) observations. The overall FTIR and CrIS total columns have a positive correlation of r = 0.77 (N = 218) with very little bias (a slope of 1.02). Furthermore, we find that CrIS and FTIR profile comparison differences are mostly within the range of the estimated retrieval uncertainties, with differences in the range of ~ 20 to 40 %.
Matthias Buschmann, Nicholas M. Deutscher, Mathias Palm, Thorsten Warneke, Christine Weinzierl, and Justus Notholt
Atmos. Meas. Tech., 10, 2397–2411, https://doi.org/10.5194/amt-10-2397-2017, https://doi.org/10.5194/amt-10-2397-2017, 2017
Short summary
Short summary
The column averaged dry-air mole fractions of CO2 and CH4 (xCO2 and xCH4) of the Total Carbon Column Observing Network (TCCON) are retrieved from solar absorption Fourier transform infrared (FTIR) spectrometry. At the Ny-Ålesund site in the high arctic, however, during the polar night no solar measurements are possible. Here, we present a new method to measure xCO2 and xCH4 using the moon as a light source in the near-infrared and present the complete seasonal cycles of xCO2 and xCH4.
Youwen Sun, Mathias Palm, Christine Weinzierl, Christof Petri, Justus Notholt, Yuting Wang, and Cheng Liu
Atmos. Meas. Tech., 10, 989–997, https://doi.org/10.5194/amt-10-989-2017, https://doi.org/10.5194/amt-10-989-2017, 2017
Short summary
Short summary
We first design experiments to investigate the sensitivity of ILS (instrumental line shape) monitoring for a high-resolution FTIR spectrometer within the TCCON and NDACC networks with respect to different optical attenuators. The ILS characteristics derived from lamp and sun spectra are in good agreement. A potential strategy to adapt incident intensity of a detector was deduced.
Klemens Hocke, Franziska Schranz, Eliane Maillard Barras, Lorena Moreira, and Niklaus Kämpfer
Atmos. Chem. Phys., 17, 3445–3452, https://doi.org/10.5194/acp-17-3445-2017, https://doi.org/10.5194/acp-17-3445-2017, 2017
Short summary
Short summary
Observation and simulation show an Atlantic ozone streamer along the edge region of the polar vortex in the northern middle stratosphere during winter. The Atlantic streamer has wind speeds of about 100 m/s and turns equatorward at a vortex erosion region. We compare the fields of stratospheric ozone and water vapour from ground- and space-based microwave radiometry and SD-WACCM simulations for a better understanding of non-linear transport processes in the middle atmosphere.
Niall J. Ryan, Mathias Palm, Uwe Raffalski, Richard Larsson, Gloria Manney, Luis Millán, and Justus Notholt
Earth Syst. Sci. Data, 9, 77–89, https://doi.org/10.5194/essd-9-77-2017, https://doi.org/10.5194/essd-9-77-2017, 2017
Short summary
Short summary
We present a self-consistent data set of carbon monoxide (CO) in the Arctic middle atmosphere above Kiruna, Sweden, between 2008 and 2015. The data are retrieved from measurements made by the ground-based radiometer, KIMRA, and are compared to coincident CO data measured by the satellite instrument MLS. KIMRA shows agreement with MLS over the altitude range in which KIMRA is sensitive (48–84 km) and the data show the signatures of dynamic processes such as sudden stratospheric warmings.
Francisco Navas-Guzmán, Niklaus Kämpfer, and Alexander Haefele
Atmos. Meas. Tech., 9, 4587–4600, https://doi.org/10.5194/amt-9-4587-2016, https://doi.org/10.5194/amt-9-4587-2016, 2016
Short summary
Short summary
The paper presents the assessment of the tropospheric measurements of a new temperature radiometer (TEMPERA) at 60 GHz. The temperature profiles from TEMPERA are compared with independent in situ radiosonde measurements. The TEMPERA performance is also compared with that of a commercial microwave radiometer (HATPRO). In addition, the brightness temperatures from both microwave radiometers are compared with the ones simulated using a radiative transfer model, ARTS.
Klemens Hocke, Martin Lainer, Lorena Moreira, Jonas Hagen, Susana Fernandez Vidal, and Franziska Schranz
Ann. Geophys., 34, 781–788, https://doi.org/10.5194/angeo-34-781-2016, https://doi.org/10.5194/angeo-34-781-2016, 2016
Short summary
Short summary
The dense horizontal sampling of atmospheric temperature profiles by the microwave limb sounder MLS on the NASA satellite AURA permit the estimation of global distributions of inertia-gravity waves (IGWs) in the middle atmosphere. We present and discuss the estimated global distributions of IGWs for July 2015 and January 2016. A dependence on the zonal wind distribution is obvious. The distributions of IGWs are a bit similar to the global distributions of small-scale gravity waves.
Lorena Moreira, Klemens Hocke, Francisco Navas-Guzmán, Ellen Eckert, Thomas von Clarmann, and Niklaus Kämpfer
Atmos. Chem. Phys., 16, 10455–10467, https://doi.org/10.5194/acp-16-10455-2016, https://doi.org/10.5194/acp-16-10455-2016, 2016
Short summary
Short summary
The GROMOS radiometer in Bern has been part of the NDACC since 1994. Our time series of stratospheric ozone profiles allow the assessment of natural oscillations, which are essential for the evaluation of detected stratospheric ozone trends. Among our new findings are the link between the upper stratospheric O3-SAO and the polar stratopause warmings in winter. We have also detected a strong peak amplitude of 5 % related to the solar activity cycle and the ENSO effect in ozone at midlatitudes.
Susana Fernandez, Rolf Rüfenacht, Niklaus Kämpfer, Thierry Portafaix, Françoise Posny, and Guillaume Payen
Atmos. Chem. Phys., 16, 7531–7543, https://doi.org/10.5194/acp-16-7531-2016, https://doi.org/10.5194/acp-16-7531-2016, 2016
Short summary
Short summary
We present a new ground based microwave radiometer for campaigns, GROMOS-C. It measures the vertical distribution of ozone in the middle atmosphere by observing spectra at 110.836 GHz. The paper presents a validation campaign that took place on La Réunion Island. The ozone retrieved profiles are validated against ozone profiles from the Microwave Limb Sounder, the ozone lidar located in the observatory, ozone profiles from weekly radiosondes and with ECMWF model data.
Rolf Rüfenacht, Klemens Hocke, and Niklaus Kämpfer
Atmos. Chem. Phys., 16, 4915–4925, https://doi.org/10.5194/acp-16-4915-2016, https://doi.org/10.5194/acp-16-4915-2016, 2016
Short summary
Short summary
We quantitatively analyze oscillations with periods from 5 to 50 days in horizontal wind profiles between mid-stratosphere and mesopause based on more than 44 months of data from high, mid- and low latitudes measured by a novel instrument. For the first time, long time series of continuous wind measurements allow direct observations of dynamics throughout this altitude range. The observations agree remarkably well with the ECMWF model in the stratosphere but discrepancies exist in the mesosphere.
L. Moreira, K. Hocke, E. Eckert, T. von Clarmann, and N. Kämpfer
Atmos. Chem. Phys., 15, 10999–11009, https://doi.org/10.5194/acp-15-10999-2015, https://doi.org/10.5194/acp-15-10999-2015, 2015
Short summary
Short summary
GROMOS (GROund-based Millimeter-wave Ozone Spectrometer) has provided ozone profiles for the NDACC (Network for the Detection of Atmospheric Composition Change) at Bern since 1994. We performed a trend analysis of our 20-year time series of stratospheric ozone profiles with a multilinear parametric trend estimation method. With our estimated ozone trends we are able to support the stratospheric ozone turnaround, besides a statistically significant negative trend in the lower mesosphere.
M. Lainer, N. Kämpfer, B. Tschanz, G. E. Nedoluha, S. Ka, and J. J. Oh
Atmos. Chem. Phys., 15, 9711–9730, https://doi.org/10.5194/acp-15-9711-2015, https://doi.org/10.5194/acp-15-9711-2015, 2015
Short summary
Short summary
We use water vapor profiles from ground-based microwave radiometers at five locations distributed over the Northern Hemisphere and operated in the frame of NDACC (Network for the Detection of Atmospheric Composition Change) to generate hemispheric water vapor maps based on the so-called trajectory mapping technique. The novelty is to show that a mini network of instruments is capable of providing information about the hemispheric distribution of water vapor under most conditions.
S. Fernandez, A. Murk, and N. Kämpfer
Atmos. Meas. Tech., 8, 2649–2662, https://doi.org/10.5194/amt-8-2649-2015, https://doi.org/10.5194/amt-8-2649-2015, 2015
B. Tschanz and N. Kämpfer
Atmos. Chem. Phys., 15, 5099–5108, https://doi.org/10.5194/acp-15-5099-2015, https://doi.org/10.5194/acp-15-5099-2015, 2015
F. Navas-Guzmán, N. Kämpfer, A. Murk, R. Larsson, S. A. Buehler, and P. Eriksson
Atmos. Meas. Tech., 8, 1863–1874, https://doi.org/10.5194/amt-8-1863-2015, https://doi.org/10.5194/amt-8-1863-2015, 2015
Short summary
Short summary
In this work we study the Zeeman effect on stratospheric O2 using ground-based microwave radiometer measurements. The interaction of the Earth magnetic field with the oxygen dipole leads to a splitting of O2 energy states which polarizes the emission spectra. A special campaign was carried out in order to measure for the first time the polarization state of the radiation due to the Zeeman effect in the main isotopologue of oxygen from ground-based microwave measurements.
S. Barthlott, M. Schneider, F. Hase, A. Wiegele, E. Christner, Y. González, T. Blumenstock, S. Dohe, O. E. García, E. Sepúlveda, K. Strong, J. Mendonca, D. Weaver, M. Palm, N. M. Deutscher, T. Warneke, J. Notholt, B. Lejeune, E. Mahieu, N. Jones, D. W. T. Griffith, V. A. Velazco, D. Smale, J. Robinson, R. Kivi, P. Heikkinen, and U. Raffalski
Atmos. Meas. Tech., 8, 1555–1573, https://doi.org/10.5194/amt-8-1555-2015, https://doi.org/10.5194/amt-8-1555-2015, 2015
A. Schanz, K. Hocke, N. Kämpfer, S. Chabrillat, A. Inness, M. Palm, J. Notholt, I. Boyd, A. Parrish, and Y. Kasai
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acpd-14-32667-2014, https://doi.org/10.5194/acpd-14-32667-2014, 2014
Revised manuscript not accepted
Short summary
Short summary
The manuscript describes novel findings in the diurnal variation of stratospheric ozone by means of the MACC reanalysis, the ERA-Interim reanalysis and the WACCM model. The diurnal variation in ozone has dynamical and photochemical origins which lead to substantial amplitudes especially in the polar, stratospheric regions. The unprecedented, global view on diurnal ozone variation strengthens the implication to correct diurnally sampled satellite observations used for ozone trend estimates.
R. Rüfenacht, A. Murk, N. Kämpfer, P. Eriksson, and S. A. Buehler
Atmos. Meas. Tech., 7, 4491–4505, https://doi.org/10.5194/amt-7-4491-2014, https://doi.org/10.5194/amt-7-4491-2014, 2014
Short summary
Short summary
Only very few techniques for wind measurements in the upper stratosphere and lower mesosphere exist. Moreover, none of these instruments is running on a continuous basis. This paper describes the development of ground-based microwave Doppler radiometry. Time series of daily wind profile measurements from four different locations at polar, mid- and tropical latitudes are presented. The agreement with ECMWF model data is good in the stratosphere, but discrepancies were found in the mesosphere.
A. Ostler, R. Sussmann, M. Rettinger, N. M. Deutscher, S. Dohe, F. Hase, N. Jones, M. Palm, and B.-M. Sinnhuber
Atmos. Meas. Tech., 7, 4081–4101, https://doi.org/10.5194/amt-7-4081-2014, https://doi.org/10.5194/amt-7-4081-2014, 2014
Short summary
Short summary
Ground-based FTIR soundings of column-average methane from NDACC and TCCON can be combined without the need to apply an overall calibration factor. NDACC and TCCON measurements complement one another and provide valuable information for satellite validation, evaluation of chemical-transport models, and source-sink inversions. The impact of dynamical variability on NDACC and TCCON retrievals of column-average methane is reflected in different smoothing effects.
S. Kowalewski, C. von Savigny, M. Palm, I. C. McDade, and J. Notholt
Atmos. Chem. Phys., 14, 10193–10210, https://doi.org/10.5194/acp-14-10193-2014, https://doi.org/10.5194/acp-14-10193-2014, 2014
E. Sepúlveda, M. Schneider, F. Hase, S. Barthlott, D. Dubravica, O. E. García, A. Gomez-Pelaez, Y. González, J. C. Guerra, M. Gisi, R. Kohlhepp, S. Dohe, T. Blumenstock, K. Strong, D. Weaver, M. Palm, A. Sadeghi, N. M. Deutscher, T. Warneke, J. Notholt, N. Jones, D. W. T. Griffith, D. Smale, G. W. Brailsford, J. Robinson, F. Meinhardt, M. Steinbacher, T. Aalto, and D. Worthy
Atmos. Meas. Tech., 7, 2337–2360, https://doi.org/10.5194/amt-7-2337-2014, https://doi.org/10.5194/amt-7-2337-2014, 2014
A. Schanz, K. Hocke, and N. Kämpfer
Atmos. Chem. Phys., 14, 7645–7663, https://doi.org/10.5194/acp-14-7645-2014, https://doi.org/10.5194/acp-14-7645-2014, 2014
D. Scheiben, B. Tschanz, K. Hocke, N. Kämpfer, S. Ka, and J. J. Oh
Atmos. Chem. Phys., 14, 6511–6522, https://doi.org/10.5194/acp-14-6511-2014, https://doi.org/10.5194/acp-14-6511-2014, 2014
S. Studer, K. Hocke, A. Schanz, H. Schmidt, and N. Kämpfer
Atmos. Chem. Phys., 14, 5905–5919, https://doi.org/10.5194/acp-14-5905-2014, https://doi.org/10.5194/acp-14-5905-2014, 2014
F. Navas-Guzmán, O. Stähli, and N. Kämpfer
Atmos. Meas. Tech., 7, 1619–1628, https://doi.org/10.5194/amt-7-1619-2014, https://doi.org/10.5194/amt-7-1619-2014, 2014
O. Stähli, A. Murk, N. Kämpfer, C. Mätzler, and P. Eriksson
Atmos. Meas. Tech., 6, 2477–2494, https://doi.org/10.5194/amt-6-2477-2013, https://doi.org/10.5194/amt-6-2477-2013, 2013
D. Scheiben, A. Schanz, B. Tschanz, and N. Kämpfer
Atmos. Chem. Phys., 13, 6877–6886, https://doi.org/10.5194/acp-13-6877-2013, https://doi.org/10.5194/acp-13-6877-2013, 2013
B. Tschanz, C. Straub, D. Scheiben, K. A. Walker, G. P. Stiller, and N. Kämpfer
Atmos. Meas. Tech., 6, 1725–1745, https://doi.org/10.5194/amt-6-1725-2013, https://doi.org/10.5194/amt-6-1725-2013, 2013
S. Studer, K. Hocke, M. Pastel, S. Godin-Beekmann, and N. Kämpfer
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amtd-6-6097-2013, https://doi.org/10.5194/amtd-6-6097-2013, 2013
Revised manuscript has not been submitted
Z. Mariani, K. Strong, M. Palm, R. Lindenmaier, C. Adams, X. Zhao, V. Savastiouk, C. T. McElroy, F. Goutail, and J. R. Drummond
Atmos. Meas. Tech., 6, 1549–1565, https://doi.org/10.5194/amt-6-1549-2013, https://doi.org/10.5194/amt-6-1549-2013, 2013
K. Hocke, S. Studer, O. Martius, D. Scheiben, and N. Kämpfer
Ann. Geophys., 31, 755–764, https://doi.org/10.5194/angeo-31-755-2013, https://doi.org/10.5194/angeo-31-755-2013, 2013
M. Schneider, S. Barthlott, F. Hase, Y. González, K. Yoshimura, O. E. García, E. Sepúlveda, A. Gomez-Pelaez, M. Gisi, R. Kohlhepp, S. Dohe, T. Blumenstock, A. Wiegele, E. Christner, K. Strong, D. Weaver, M. Palm, N. M. Deutscher, T. Warneke, J. Notholt, B. Lejeune, P. Demoulin, N. Jones, D. W. T. Griffith, D. Smale, and J. Robinson
Atmos. Meas. Tech., 5, 3007–3027, https://doi.org/10.5194/amt-5-3007-2012, https://doi.org/10.5194/amt-5-3007-2012, 2012
Related subject area
Subject: Gases | Research Activity: Remote Sensing | Altitude Range: Stratosphere | Science Focus: Chemistry (chemical composition and reactions)
Ozone anomalies over the polar regions during stratospheric warming events
No severe ozone depletion in the tropical stratosphere in recent decades
The Antarctic stratospheric nitrogen hole: Southern Hemisphere and Antarctic springtime total nitrogen dioxide and total ozone variability as observed by Sentinel-5p TROPOMI
Solar FTIR measurements of NOx vertical distributions – Part 1: First observational evidence of a seasonal variation in the diurnal increasing rates of stratospheric NO2 and NO
Emissions of Methane from Coal, Thermal power plants and Wetlands and its implications on Atmospheric Methane across the South Asian Region
Trends in polar ozone loss since 1989: potential sign of recovery in the Arctic ozone column
Climatology, sources, and transport characteristics of observed water vapor extrema in the lower stratosphere
Impact of chlorine ion chemistry on ozone loss in the middle atmosphere during very large solar proton events
Total ozone variability and trends over the South Pole during the wintertime
Inferring the photolysis rate of NO2 in the stratosphere based on satellite observations
Technical note: On HALOE stratospheric water vapor variations and trends at Boulder, Colorado
Microwave radiometer observations of the ozone diurnal cycle and its short-term variability over Switzerland
Observed changes in stratospheric circulation: decreasing lifetime of N2O, 2005–2021
Water vapour and ozone in the upper troposphere–lower stratosphere: global climatologies from three Canadian limb-viewing instruments
Updated trends of the stratospheric ozone vertical distribution in the 60° S–60° N latitude range based on the LOTUS regression model
Polar stratospheric nitric acid depletion surveyed from a decadal dataset of IASI total columns
Global total ozone recovery trends attributed to ozone-depleting substance (ODS) changes derived from five merged ozone datasets
Global, regional and seasonal analysis of total ozone trends derived from the 1995–2020 GTO-ECV climate data record
Upper stratospheric ClO and HOCl trends (2005–2020): Aura Microwave Limb Sounder and model results
Challenge of modelling GLORIA observations of upper troposphere–lowermost stratosphere trace gas and cloud distributions at high latitudes: a case study with state-of-the-art models
A single-peak-structured solar cycle signal in stratospheric ozone based on Microwave Limb Sounder observations and model simulations
OClO as observed by TROPOMI: a comparison with meteorological parameters and polar stratospheric cloud observations
The Michelson Interferometer for Passive Atmospheric Sounding global climatology of BrONO2 2002–2012: a test for stratospheric bromine chemistry
Microwave Limb Sounder (MLS) observations of biomass burning products in the stratosphere from Canadian forest fires in August 2017
Exceptional loss in ozone in the Arctic winter/spring of 2019/2020
Fifty years of balloon-borne ozone profile measurements at Uccle, Belgium: a short history, the scientific relevance, and the achievements in understanding the vertical ozone distribution
On the use of satellite observations to fill gaps in the Halley station total ozone record
Pollution trace gases C2H6, C2H2, HCOOH, and PAN in the North Atlantic UTLS: observations and simulations
Measurement report: regional trends of stratospheric ozone evaluated using the MErged GRIdded Dataset of Ozone Profiles (MEGRIDOP)
Indicators of Antarctic ozone depletion: 1979 to 2019
Observational evidence of energetic particle precipitation NOx (EPP-NOx) interaction with chlorine curbing Antarctic ozone loss
Total column ozone in New Zealand and in the UK in the 1950s
Study of the dependence of long-term stratospheric ozone trends on local solar time
Technical note: LIMS observations of lower stratospheric ozone in the southern polar springtime of 1978
Chlorine partitioning near the polar vortex edge observed with ground-based FTIR and satellites at Syowa Station, Antarctica, in 2007 and 2011
Is the recovery of stratospheric O3 speeding up in the Southern Hemisphere? An evaluation from the first IASI decadal record (2008–2017)
Nitrification of the lowermost stratosphere during the exceptionally cold Arctic winter 2015–2016
Improved FTIR retrieval strategy for HCFC-22 (CHClF2), comparisons with in situ and satellite datasets with the support of models, and determination of its long-term trend above Jungfraujoch
A study on harmonizing total ozone assimilation with multiple sensors
Unusual chlorine partitioning in the 2015/16 Arctic winter lowermost stratosphere: observations and simulations
Dynamically controlled ozone decline in the tropical mid-stratosphere observed by SCIAMACHY
Stratospheric ozone loss in the Arctic winters between 2005 and 2013 derived with ACE-FTS measurements
Space–time variability in UTLS chemical distribution in the Asian summer monsoon viewed by limb and nadir satellite sensors
Using satellite measurements of N2O to remove dynamical variability from HCl measurements
Middle atmospheric ozone, nitrogen dioxide and nitrogen trioxide in 2002–2011: SD-WACCM simulations compared to GOMOS observations
The Network for the Detection of Atmospheric Composition Change (NDACC): history, status and perspectives
Spatio-temporal variations of nitric acid total columns from 9 years of IASI measurements – a driver study
Total ozone trends from 1979 to 2016 derived from five merged observational datasets – the emergence into ozone recovery
The impact of nonuniform sampling on stratospheric ozone trends derived from occultation instruments
Diurnal variations of BrONO2 observed by MIPAS-B at midlatitudes and in the Arctic
Guochun Shi, Witali Krochin, Eric Sauvageat, and Gunter Stober
Atmos. Chem. Phys., 24, 10187–10207, https://doi.org/10.5194/acp-24-10187-2024, https://doi.org/10.5194/acp-24-10187-2024, 2024
Short summary
Short summary
Here we investigated ozone anomalies over polar regions during sudden stratospheric and final stratospheric warming with ground-based microwave radiometers at polar latitudes compared with reanalysis and satellite data. The underlying dynamical and chemical mechanisms are responsible for the observed ozone anomalies in both events. Our research sheds light on these processes, emphasizing the need for a deeper understanding of these processes for more accurate climate modeling and forecasting.
Jayanarayanan Kuttippurath, Gopalakrishna Pillai Gopikrishnan, Rolf Müller, Sophie Godin-Beekmann, and Jerome Brioude
Atmos. Chem. Phys., 24, 6743–6756, https://doi.org/10.5194/acp-24-6743-2024, https://doi.org/10.5194/acp-24-6743-2024, 2024
Short summary
Short summary
The current understanding and observational evidence do not provide any support for the possibility of an ozone hole occurring outside Antarctica today with respect to the present-day stratospheric halogen levels.
Adrianus de Laat, Jos van Geffen, Piet Stammes, Ronald van der A, Henk Eskes, and J. Pepijn Veefkind
Atmos. Chem. Phys., 24, 4511–4535, https://doi.org/10.5194/acp-24-4511-2024, https://doi.org/10.5194/acp-24-4511-2024, 2024
Short summary
Short summary
Removal of stratospheric nitrogen oxides is crucial for the formation of the ozone hole. TROPOMI satellite measurements of nitrogen dioxide reveal the presence of a not dissimilar "nitrogen hole" that largely coincides with the ozone hole. Three very distinct regimes were identified: inside and outside the ozone hole and the transition zone in between. Our results introduce a valuable and innovative application highly relevant for Antarctic ozone hole and ozone layer recovery.
Pinchas Nürnberg, Markus Rettinger, and Ralf Sussmann
Atmos. Chem. Phys., 24, 3743–3757, https://doi.org/10.5194/acp-24-3743-2024, https://doi.org/10.5194/acp-24-3743-2024, 2024
Short summary
Short summary
For a better understanding of stratospheric photochemistry, we analyzed long-term data from spectroscopic measurements at Zugspitze and Garmisch, Germany. We provide information about the seasonal cycle of diurnal nitrogen oxide variation in the stratosphere. For the first time we create an experimental data set to validate stratospheric model simulation that can improve satellite validation to gain further insights into ozone depletion and smog prevention.
Mahalakshmi D.Venkata, Mahesh Pathakoti, A. Lakshmi Kanchana, Sujatha Peethani, Ibrahim Shaik, Krishnan Sundara Rajan, Vijay Kumar Sagar, Pushpanathan Raja, Yogesh Kumar Tiwari, and Chauhan Prakash
EGUsphere, https://doi.org/10.5194/egusphere-2024-405, https://doi.org/10.5194/egusphere-2024-405, 2024
Short summary
Short summary
The present study investigated the variability of CH4 over coal fields, power plants, and wetlands using the long-term GOSAT and TROPOMI data. Interestingly noticed a slow growth rate of CH4 over the second-largest wetland areas of India. The Sundarbans wetland growth rate competes with coal sites with the production of over 30 MT. Further mapped CH4 concentrations against the emissions in the Agro-climatic zones and found a statistically high correlation in the Indo-Gangetic Plain regions.
Andrea Pazmiño, Florence Goutail, Sophie Godin-Beekmann, Alain Hauchecorne, Jean-Pierre Pommereau, Martyn P. Chipperfield, Wuhu Feng, Franck Lefèvre, Audrey Lecouffe, Michel Van Roozendael, Nis Jepsen, Georg Hansen, Rigel Kivi, Kimberly Strong, and Kaley A. Walker
Atmos. Chem. Phys., 23, 15655–15670, https://doi.org/10.5194/acp-23-15655-2023, https://doi.org/10.5194/acp-23-15655-2023, 2023
Short summary
Short summary
The vortex-averaged ozone loss over the last 3 decades is evaluated for both polar regions using the passive ozone tracer of the chemical transport model TOMCAT/SLIMCAT and total ozone observations from the SAOZ network and MSR2 reanalysis. Three metrics were developed to compute ozone trends since 2000. The study confirms the ozone recovery in the Antarctic and shows a potential sign of quantitative detection of ozone recovery in the Arctic that needs to be robustly confirmed in the future.
Emily N. Tinney and Cameron R. Homeyer
Atmos. Chem. Phys., 23, 14375–14392, https://doi.org/10.5194/acp-23-14375-2023, https://doi.org/10.5194/acp-23-14375-2023, 2023
Short summary
Short summary
A long-term record of satellite observations is used to study extreme water vapor concentrations in the lower stratosphere, which are important to climate variability and change. We use a deeper layer of stratospheric observations than prior work to more comprehensively identify these events. We show that extreme water vapor concentrations are frequent, especially in the lowest layers of the stratosphere that have not been analyzed previously.
Monali Borthakur, Miriam Sinnhuber, Alexandra Laeng, Thomas Reddmann, Peter Braesicke, Gabriele Stiller, Thomas von Clarmann, Bernd Funke, Ilya Usoskin, Jan Maik Wissing, and Olesya Yakovchuk
Atmos. Chem. Phys., 23, 12985–13013, https://doi.org/10.5194/acp-23-12985-2023, https://doi.org/10.5194/acp-23-12985-2023, 2023
Short summary
Short summary
Reduced ozone levels resulting from ozone depletion mean more exposure to UV radiation, which has various effects on human health. We analysed solar events to see what influence it has on the chemistry of Earth's atmosphere and how this atmospheric chemistry change can affect the ozone. To do this, we used an atmospheric model considering only chemistry and compared it with satellite data. The focus was mainly on the contribution of chlorine, and we found about 10 %–20 % ozone loss due to that.
Vitali Fioletov, Xiaoyi Zhao, Ihab Abboud, Michael Brohart, Akira Ogyu, Reno Sit, Sum Chi Lee, Irina Petropavlovskikh, Koji Miyagawa, Bryan J. Johnson, Patrick Cullis, John Booth, Glen McConville, and C. Thomas McElroy
Atmos. Chem. Phys., 23, 12731–12751, https://doi.org/10.5194/acp-23-12731-2023, https://doi.org/10.5194/acp-23-12731-2023, 2023
Short summary
Short summary
Stratospheric ozone within the Southern Hemisphere springtime polar vortex has been a subject of intense research since the discovery of the Antarctic ozone hole. The wintertime ozone in the vortex is less studied. We show that the recent wintertime ozone values over the South Pole were about 12 % below the pre-1980s level; i.e., the decline there was nearly twice as large as that over southern midlatitudes. Thus, wintertime ozone there can be used as an indicator of the ozone layer state.
Jian Guan, Susan Solomon, Sasha Madronich, and Douglas Kinnison
Atmos. Chem. Phys., 23, 10413–10422, https://doi.org/10.5194/acp-23-10413-2023, https://doi.org/10.5194/acp-23-10413-2023, 2023
Short summary
Short summary
This paper provides a novel method to obtain a global and accurate photodissociation coefficient for NO2 (J(NO2)) based on satellite data, and the results are shown to be consistent with model results. The J(NO2) value decreases as the solar zenith angle increases and has a weak altitude dependence. A key finding is that the satellite-derived J(NO2) increases in the polar regions, in good agreement with model predictions, due to the effects of ice and snow on surface albedo.
Ellis Remsberg
Atmos. Chem. Phys., 23, 9637–9646, https://doi.org/10.5194/acp-23-9637-2023, https://doi.org/10.5194/acp-23-9637-2023, 2023
Short summary
Short summary
This study compares analysis of trends in stratospheric water vapor from the Halogen Occultation Experiment satellite instrument with those from local frost-point hygrometers (FPHs) at 30 and 50 hPa over Boulder, Colorado (40°N), for 1993 to 2005. The FPH measurements are assumed correct. However, the seasonal sampling by HALOE is marginal from 2002 to 2005, such that its trends have a bias after 2001. Trend comparisons for 1993 to 2002 at 30 hPa agree within the uncertainties of both datasets.
Eric Sauvageat, Klemens Hocke, Eliane Maillard Barras, Shengyi Hou, Quentin Errera, Alexander Haefele, and Axel Murk
Atmos. Chem. Phys., 23, 7321–7345, https://doi.org/10.5194/acp-23-7321-2023, https://doi.org/10.5194/acp-23-7321-2023, 2023
Short summary
Short summary
In Switzerland, two microwave radiometers can measure continuous ozone profiles in the middle atmosphere. From these instruments, we can study the diurnal variation of ozone, which is difficult to observe otherwise. It is valuable to validate the model simulations of diurnal variations in this region. We present results obtained during the last decade and compare them against various models. For the first time, we also show that the winter diurnal variations have some short-term fluctuations.
Michael J. Prather, Lucien Froidevaux, and Nathaniel J. Livesey
Atmos. Chem. Phys., 23, 843–849, https://doi.org/10.5194/acp-23-843-2023, https://doi.org/10.5194/acp-23-843-2023, 2023
Short summary
Short summary
From satellite data for nitrous oxide (N2O), ozone and temperature, we calculate the monthly loss of N2O and find it is increasing faster than expected, resulting in a shorter lifetime, which reduces the impact of anthropogenic emissions. We identify the cause as enhanced vertical lofting of high-N2O air into the tropical middle stratosphere, where it is destroyed photochemically. Because global warming is due in part to N2O, this finding presents a new negative climate-chemistry feedback.
Paul S. Jeffery, Kaley A. Walker, Chris E. Sioris, Chris D. Boone, Doug Degenstein, Gloria L. Manney, C. Thomas McElroy, Luis Millán, David A. Plummer, Niall J. Ryan, Patrick E. Sheese, and Jiansheng Zou
Atmos. Chem. Phys., 22, 14709–14734, https://doi.org/10.5194/acp-22-14709-2022, https://doi.org/10.5194/acp-22-14709-2022, 2022
Short summary
Short summary
The upper troposphere–lower stratosphere is one of the most variable regions in the atmosphere. To improve our understanding of water vapour and ozone concentrations in this region, climatologies have been developed from 14 years of measurements from three Canadian satellite instruments. Horizontal and vertical coordinates have been chosen to minimize the effects of variability. To aid in analysis, model simulations have been used to characterize differences between instrument climatologies.
Sophie Godin-Beekmann, Niramson Azouz, Viktoria F. Sofieva, Daan Hubert, Irina Petropavlovskikh, Peter Effertz, Gérard Ancellet, Doug A. Degenstein, Daniel Zawada, Lucien Froidevaux, Stacey Frith, Jeannette Wild, Sean Davis, Wolfgang Steinbrecht, Thierry Leblanc, Richard Querel, Kleareti Tourpali, Robert Damadeo, Eliane Maillard Barras, René Stübi, Corinne Vigouroux, Carlo Arosio, Gerald Nedoluha, Ian Boyd, Roeland Van Malderen, Emmanuel Mahieu, Dan Smale, and Ralf Sussmann
Atmos. Chem. Phys., 22, 11657–11673, https://doi.org/10.5194/acp-22-11657-2022, https://doi.org/10.5194/acp-22-11657-2022, 2022
Short summary
Short summary
An updated evaluation up to 2020 of stratospheric ozone profile long-term trends at extrapolar latitudes based on satellite and ground-based records is presented. Ozone increase in the upper stratosphere is confirmed, with significant trends at most latitudes. In this altitude region, a very good agreement is found with trends derived from chemistry–climate model simulations. Observed and modelled trends diverge in the lower stratosphere, but the differences are non-significant.
Catherine Wespes, Gaetane Ronsmans, Lieven Clarisse, Susan Solomon, Daniel Hurtmans, Cathy Clerbaux, and Pierre-François Coheur
Atmos. Chem. Phys., 22, 10993–11007, https://doi.org/10.5194/acp-22-10993-2022, https://doi.org/10.5194/acp-22-10993-2022, 2022
Short summary
Short summary
The first 10-year data record (2008–2017) of HNO3 total columns measured by the IASI-A/MetOp infrared sounder is exploited to monitor the relationship between the temperature decrease and the HNO3 loss observed each year in the Antarctic stratosphere during the polar night. We verify the recurrence of specific regimes in the cycle of IASI HNO3 and identify the day and the 50 hPa temperature (
drop temperature) corresponding to the onset of denitrification in Antarctic winter for each year.
Mark Weber, Carlo Arosio, Melanie Coldewey-Egbers, Vitali E. Fioletov, Stacey M. Frith, Jeannette D. Wild, Kleareti Tourpali, John P. Burrows, and Diego Loyola
Atmos. Chem. Phys., 22, 6843–6859, https://doi.org/10.5194/acp-22-6843-2022, https://doi.org/10.5194/acp-22-6843-2022, 2022
Short summary
Short summary
Long-term trends in column ozone have been determined from five merged total ozone datasets spanning the period 1978–2020. We show that ozone recovery due to the decline in stratospheric halogens after the 1990s (as regulated by the Montreal Protocol) is evident outside the tropical region and amounts to half a percent per decade. The ozone recovery in the Northern Hemisphere is however compensated for by the negative long-term trend contribution from atmospheric dynamics since the year 2000.
Melanie Coldewey-Egbers, Diego G. Loyola, Christophe Lerot, and Michel Van Roozendael
Atmos. Chem. Phys., 22, 6861–6878, https://doi.org/10.5194/acp-22-6861-2022, https://doi.org/10.5194/acp-22-6861-2022, 2022
Short summary
Short summary
Monitoring the long-term evolution of ozone and the evaluation of trends is essential to assess the efficacy of the Montreal Protocol and its amendments. The first signs of recovery as a consequence of decreasing amounts of ozone-depleting substances have been reported, but the impact needs to be investigated in more detail. In the Southern Hemisphere significant positive trends were found, but in the Northern Hemisphere the expected increase is still not yet visible.
Lucien Froidevaux, Douglas E. Kinnison, Michelle L. Santee, Luis F. Millán, Nathaniel J. Livesey, William G. Read, Charles G. Bardeen, John J. Orlando, and Ryan A. Fuller
Atmos. Chem. Phys., 22, 4779–4799, https://doi.org/10.5194/acp-22-4779-2022, https://doi.org/10.5194/acp-22-4779-2022, 2022
Short summary
Short summary
We analyze satellite-derived distributions of chlorine monoxide (ClO) and hypochlorous acid (HOCl) in the upper atmosphere. For 2005–2020, from 50°S to 50°N and over ~30 to 45 km, ClO and HOCl decreased by −0.7 % and −0.4 % per year, respectively. A detailed model of chemistry and dynamics agrees with the results. These decreases confirm the effectiveness of the 1987 Montreal Protocol, which limited emissions of chlorine- and bromine-containing source gases, in order to protect the ozone layer.
Florian Haenel, Wolfgang Woiwode, Jennifer Buchmüller, Felix Friedl-Vallon, Michael Höpfner, Sören Johansson, Farahnaz Khosrawi, Oliver Kirner, Anne Kleinert, Hermann Oelhaf, Johannes Orphal, Roland Ruhnke, Björn-Martin Sinnhuber, Jörn Ungermann, Michael Weimer, and Peter Braesicke
Atmos. Chem. Phys., 22, 2843–2870, https://doi.org/10.5194/acp-22-2843-2022, https://doi.org/10.5194/acp-22-2843-2022, 2022
Short summary
Short summary
We compare remote sensing observations of H2O, O3, HNO3 and clouds in the upper troposphere–lowermost stratosphere during an Arctic winter long-range research flight with simulations by two different state-of-the-art model systems. We find good agreement for dynamical structures, trace gas distributions and clouds. We investigate model biases and sensitivities, with the goal of aiding model development and improving our understanding of processes in the upper troposphere–lowermost stratosphere.
Sandip S. Dhomse, Martyn P. Chipperfield, Wuhu Feng, Ryan Hossaini, Graham W. Mann, Michelle L. Santee, and Mark Weber
Atmos. Chem. Phys., 22, 903–916, https://doi.org/10.5194/acp-22-903-2022, https://doi.org/10.5194/acp-22-903-2022, 2022
Short summary
Short summary
Solar flux variations associated with 11-year sunspot cycle is believed to exert important external climate forcing. As largest variations occur at shorter wavelengths such as ultra-violet part of the solar spectrum, associated changes in stratospheric ozone are thought to provide direct evidence for solar climate interaction. Until now, most of the studies reported double-peak structured solar cycle signal (SCS), but relatively new satellite data suggest only single-peak-structured SCS.
Jānis Puķīte, Christian Borger, Steffen Dörner, Myojeong Gu, and Thomas Wagner
Atmos. Chem. Phys., 22, 245–272, https://doi.org/10.5194/acp-22-245-2022, https://doi.org/10.5194/acp-22-245-2022, 2022
Short summary
Short summary
Chlorine dioxide (OClO) is an indicator for chlorine activation. New OClO data by TROPOMI (S5P) are interpreted in a meteorological context and related to CALIOP PSC observations. We report very high OClO levels for the northern hemispheric winter 2019/20 with an extraordinarily long period with a stable polar vortex. A minor stratospheric warming in the Southern Hemisphere was also observed in September 2019, where usual OClO values rapidly deactivated 1–2 weeks earlier.
Michael Höpfner, Oliver Kirner, Gerald Wetzel, Björn-Martin Sinnhuber, Florian Haenel, Sören Johansson, Johannes Orphal, Roland Ruhnke, Gabriele Stiller, and Thomas von Clarmann
Atmos. Chem. Phys., 21, 18433–18464, https://doi.org/10.5194/acp-21-18433-2021, https://doi.org/10.5194/acp-21-18433-2021, 2021
Short summary
Short summary
BrONO2 is an important reservoir gas for inorganic stratospheric bromine linked to the chemical cycles of stratospheric ozone depletion. Presently infrared limb sounding is the only way to measure BrONO2 in the atmosphere. We provide global distributions of BrONO2 derived from MIPAS observations 2002–2012. Comparisons with EMAC atmospheric modelling show an overall agreement and enable us to derive an independent estimate of stratospheric bromine of 21.2±1.4pptv based on the BrONO2 measurements.
Hugh C. Pumphrey, Michael J. Schwartz, Michelle L. Santee, George P. Kablick III, Michael D. Fromm, and Nathaniel J. Livesey
Atmos. Chem. Phys., 21, 16645–16659, https://doi.org/10.5194/acp-21-16645-2021, https://doi.org/10.5194/acp-21-16645-2021, 2021
Short summary
Short summary
Forest fires in British Columbia in August 2017 caused an unusual phenomonon: smoke and gases from the fires rose quickly to a height of 10 km. From there, the pollution continued to rise more slowly for many weeks, travelling around the world as it did so. In this paper, we describe how we used data from a satellite instrument to observe this polluted volume of air. The satellite has now been working for 16 years but has observed only three events of this type.
Jayanarayanan Kuttippurath, Wuhu Feng, Rolf Müller, Pankaj Kumar, Sarath Raj, Gopalakrishna Pillai Gopikrishnan, and Raina Roy
Atmos. Chem. Phys., 21, 14019–14037, https://doi.org/10.5194/acp-21-14019-2021, https://doi.org/10.5194/acp-21-14019-2021, 2021
Short summary
Short summary
The Arctic winter/spring 2020 was one of the coldest with a strong and long-lasting vortex, high chlorine activation, severe denitrification, and unprecedented ozone loss. The loss was even equal to the levels of some of the warm Antarctic winters. Total column ozone values below 220 DU for several weeks and ozone loss saturation were observed during the period. These results show an unusual meteorology and warrant dedicated studies on the impact of climate change on ozone loss.
Roeland Van Malderen, Dirk De Muer, Hugo De Backer, Deniz Poyraz, Willem W. Verstraeten, Veerle De Bock, Andy W. Delcloo, Alexander Mangold, Quentin Laffineur, Marc Allaart, Frans Fierens, and Valérie Thouret
Atmos. Chem. Phys., 21, 12385–12411, https://doi.org/10.5194/acp-21-12385-2021, https://doi.org/10.5194/acp-21-12385-2021, 2021
Short summary
Short summary
The main aim of initiating measurements of the vertical distribution of the ozone concentration by means of ozonesondes attached to weather balloons at Uccle in 1969 was to improve weather forecasts. Since then, this measurement technique has barely changed, but the dense, long-term, and homogeneous Uccle dataset currently remains crucial for studying the temporal evolution of ozone from the surface to the stratosphere and is also the backbone of the validation of satellite ozone retrievals.
Lily N. Zhang, Susan Solomon, Kane A. Stone, Jonathan D. Shanklin, Joshua D. Eveson, Steve Colwell, John P. Burrows, Mark Weber, Pieternel F. Levelt, Natalya A. Kramarova, and David P. Haffner
Atmos. Chem. Phys., 21, 9829–9838, https://doi.org/10.5194/acp-21-9829-2021, https://doi.org/10.5194/acp-21-9829-2021, 2021
Short summary
Short summary
In the 1980s, measurements at the British Antarctic Survey station in Halley, Antarctica, led to the discovery of the ozone hole. The Halley total ozone record continues to be uniquely valuable for studies of long-term changes in Antarctic ozone. Environmental conditions in 2017 forced a temporary cessation of operations, leading to a gap in the historic record. We develop and test a method for filling in the Halley record using satellite data and find evidence to further support ozone recovery.
Gerald Wetzel, Felix Friedl-Vallon, Norbert Glatthor, Jens-Uwe Grooß, Thomas Gulde, Michael Höpfner, Sören Johansson, Farahnaz Khosrawi, Oliver Kirner, Anne Kleinert, Erik Kretschmer, Guido Maucher, Hans Nordmeyer, Hermann Oelhaf, Johannes Orphal, Christof Piesch, Björn-Martin Sinnhuber, Jörn Ungermann, and Bärbel Vogel
Atmos. Chem. Phys., 21, 8213–8232, https://doi.org/10.5194/acp-21-8213-2021, https://doi.org/10.5194/acp-21-8213-2021, 2021
Short summary
Short summary
Measurements of the pollutants C2H6, C2H2, HCOOH, and PAN were performed in the North Atlantic UTLS region with the airborne limb imager GLORIA in 2017. Enhanced amounts of these species were detected in the upper troposphere and even in the lowermost stratosphere (PAN). Main sources of these gases are forest fires in North America and anthropogenic pollution in South Asia. Simulations of EMAC and CAMS are qualitatively able to reproduce the measured data but underestimate the absolute amounts.
Viktoria F. Sofieva, Monika Szeląg, Johanna Tamminen, Erkki Kyrölä, Doug Degenstein, Chris Roth, Daniel Zawada, Alexei Rozanov, Carlo Arosio, John P. Burrows, Mark Weber, Alexandra Laeng, Gabriele P. Stiller, Thomas von Clarmann, Lucien Froidevaux, Nathaniel Livesey, Michel van Roozendael, and Christian Retscher
Atmos. Chem. Phys., 21, 6707–6720, https://doi.org/10.5194/acp-21-6707-2021, https://doi.org/10.5194/acp-21-6707-2021, 2021
Short summary
Short summary
The MErged GRIdded Dataset of Ozone Profiles is a long-term (2001–2018) stratospheric ozone profile climate data record with resolved longitudinal structure that combines the data from six limb satellite instruments. The dataset can be used for various analyses, some of which are discussed in the paper. In particular, regionally and vertically resolved ozone trends are evaluated, including trends in the polar regions.
Greg E. Bodeker and Stefanie Kremser
Atmos. Chem. Phys., 21, 5289–5300, https://doi.org/10.5194/acp-21-5289-2021, https://doi.org/10.5194/acp-21-5289-2021, 2021
Short summary
Short summary
This paper presents measures of the severity of the Antarctic ozone hole covering the period 1979 to 2019. The paper shows that while the severity of Antarctic ozone depletion grew rapidly through the last two decades of the 20th century, the severity declined thereafter and faster than expected from declines in stratospheric concentrations of the chlorine- and bromine-containing chemical compounds that destroy ozone.
Emily M. Gordon, Annika Seppälä, Bernd Funke, Johanna Tamminen, and Kaley A. Walker
Atmos. Chem. Phys., 21, 2819–2836, https://doi.org/10.5194/acp-21-2819-2021, https://doi.org/10.5194/acp-21-2819-2021, 2021
Short summary
Short summary
Energetic particle precipitation (EPP) is the rain of solar energetic particles into the Earth's atmosphere. EPP is known to deplete O3 in the polar mesosphere–upper stratosphere via the formation of NOx. NOx also causes chlorine deactivation in the lower stratosphere and has, thus, been proposed to potentially result in reduced ozone depletion in the spring. We provide the first evidence to show that NOx formed by EPP is able to remove active chlorine, resulting in enhanced total ozone column.
Stefan Brönnimann and Sylvia Nichol
Atmos. Chem. Phys., 20, 14333–14346, https://doi.org/10.5194/acp-20-14333-2020, https://doi.org/10.5194/acp-20-14333-2020, 2020
Short summary
Short summary
Historical column ozone data from New Zealand and the UK from the 1950s are digitised and re-evaluated. They allow studying the ozone layer prior to the era of ozone depletion. Day-to-day changes are addressed, which reflect the flow near the tropopause and hence may serve as a diagnostic for atmospheric circulation in a time and region of sparse radiosondes. A long-term comparison shows the amount of ozone depletion at southern mid-latitudes and indicates how far we are from full recovery.
Eliane Maillard Barras, Alexander Haefele, Liliane Nguyen, Fiona Tummon, William T. Ball, Eugene V. Rozanov, Rolf Rüfenacht, Klemens Hocke, Leonie Bernet, Niklaus Kämpfer, Gerald Nedoluha, and Ian Boyd
Atmos. Chem. Phys., 20, 8453–8471, https://doi.org/10.5194/acp-20-8453-2020, https://doi.org/10.5194/acp-20-8453-2020, 2020
Short summary
Short summary
To determine the part of the variability of the long-term ozone profile trends coming from measurement timing, we estimate microwave radiometer trends for each hour of the day with a multiple linear regression model. The variation in the trend with local solar time is not significant at the 95 % confidence level either in the stratosphere or in the low mesosphere. We conclude that systematic sampling differences between instruments cannot explain significant differences in trend estimates.
Ellis Remsberg, V. Lynn Harvey, Arlin Krueger, Larry Gordley, John C. Gille, and James M. Russell III
Atmos. Chem. Phys., 20, 3663–3668, https://doi.org/10.5194/acp-20-3663-2020, https://doi.org/10.5194/acp-20-3663-2020, 2020
Short summary
Short summary
The Nimbus 7 limb infrared monitor of the stratosphere (LIMS) instrument operated from October 25, 1978, through May 28, 1979. This note focuses on the lower stratosphere of the southern hemisphere, subpolar regions in relation to the position of the polar vortex. Both LIMS ozone and nitric acid show reductions within the edge of the polar vortex at 46 hPa near 60° S from late October through mid-November 1978, indicating that there was a chemical loss of Antarctic ozone some weeks earlier.
Hideaki Nakajima, Isao Murata, Yoshihiro Nagahama, Hideharu Akiyoshi, Kosuke Saeki, Takeshi Kinase, Masanori Takeda, Yoshihiro Tomikawa, Eric Dupuy, and Nicholas B. Jones
Atmos. Chem. Phys., 20, 1043–1074, https://doi.org/10.5194/acp-20-1043-2020, https://doi.org/10.5194/acp-20-1043-2020, 2020
Short summary
Short summary
This paper presents temporal evolution of stratospheric chlorine and minor species related to Antarctic ozone depletion, based on FTIR measurements at Syowa Station, and satellite measurements by MLS and MIPAS in 2007 and 2011. After chlorine reservoir species were processed on PSCs and active ClO was formed, different chlorine deactivation pathways into reservoir species were identified, depending on the relative location of Syowa Station to the polar vortex boundary.
Catherine Wespes, Daniel Hurtmans, Simon Chabrillat, Gaétane Ronsmans, Cathy Clerbaux, and Pierre-François Coheur
Atmos. Chem. Phys., 19, 14031–14056, https://doi.org/10.5194/acp-19-14031-2019, https://doi.org/10.5194/acp-19-14031-2019, 2019
Short summary
Short summary
This paper highlights the global fingerprint of recent changes in O3 in both the middle–upper and lower stratosphere from the first 10 years of the IASI/Metop-A satellite measurements. The results present the first detection of a significant O3 recovery at middle–high latitudes in winter–spring in the stratosphere as well as in the total column from one single dataset. They also show a speeding up in the recovery at high southern latitudes contrasting with a decline at northern mid-latitudes.
Marleen Braun, Jens-Uwe Grooß, Wolfgang Woiwode, Sören Johansson, Michael Höpfner, Felix Friedl-Vallon, Hermann Oelhaf, Peter Preusse, Jörn Ungermann, Björn-Martin Sinnhuber, Helmut Ziereis, and Peter Braesicke
Atmos. Chem. Phys., 19, 13681–13699, https://doi.org/10.5194/acp-19-13681-2019, https://doi.org/10.5194/acp-19-13681-2019, 2019
Short summary
Short summary
We analyse nitrification of the LMS in the Arctic winter 2015–2016 based on GLORIA measurements. Vertical cross sections of HNO3 for several flights show complex fine–scale structures and enhanced values down to 9 km. The extent of overall nitrification is quantified based on HNO3–O3 correlations and reaches between 5 ppbv and 7 ppbv at potential temperature levels between 350 and 380 K. Further, we compare our result with the atmospheric model CLaMS.
Maxime Prignon, Simon Chabrillat, Daniele Minganti, Simon O'Doherty, Christian Servais, Gabriele Stiller, Geoffrey C. Toon, Martin K. Vollmer, and Emmanuel Mahieu
Atmos. Chem. Phys., 19, 12309–12324, https://doi.org/10.5194/acp-19-12309-2019, https://doi.org/10.5194/acp-19-12309-2019, 2019
Short summary
Short summary
Hydrochlorofluorocarbons (HCFCs) are the first, but temporary, substitution products for the strong ozone-depleting chlorofluorocarbons (CFCs). In this work, we present and validate an improved method to retrieve the most abundant HCFC in the atmosphere, allowing its evolution to be monitored independently in the troposphere and stratosphere. These kinds of contributions are fundamental for scrutinizing the fulfilment of the Montreal Protocol on Substances that Deplete the Ozone Layer.
Yves J. Rochon, Michael Sitwell, and Young-Min Cho
Atmos. Chem. Phys., 19, 9431–9451, https://doi.org/10.5194/acp-19-9431-2019, https://doi.org/10.5194/acp-19-9431-2019, 2019
Short summary
Short summary
This paper describes adaptable methodologies and results of bias correction applied for the assimilation of total column ozone data from different satellite instruments. The results demonstrate the capability of ensuring short-term forecast biases of total column ozone to be typically within 1 % of a reference for latitudinal ranges where measurements are available. The bias estimation and correction software can be utilized for measurements of other constituents.
Sören Johansson, Michelle L. Santee, Jens-Uwe Grooß, Michael Höpfner, Marleen Braun, Felix Friedl-Vallon, Farahnaz Khosrawi, Oliver Kirner, Erik Kretschmer, Hermann Oelhaf, Johannes Orphal, Björn-Martin Sinnhuber, Ines Tritscher, Jörn Ungermann, Kaley A. Walker, and Wolfgang Woiwode
Atmos. Chem. Phys., 19, 8311–8338, https://doi.org/10.5194/acp-19-8311-2019, https://doi.org/10.5194/acp-19-8311-2019, 2019
Short summary
Short summary
We present a study based on GLORIA aircraft and MLS/ACE-FTS/CALIOP satellite measurements during the Arctic winter 2015/16, which demonstrate (for the Arctic) unusual chlorine deactivation into HCl instead of ClONO2 due to low ozone abundances in the lowermost stratosphere, with a focus at 380 K potential temperature. The atmospheric models CLaMS and EMAC are evaluated, and measured ClONO2 is linked with transport and in situ deactivation in the lowermost stratosphere.
Evgenia Galytska, Alexey Rozanov, Martyn P. Chipperfield, Sandip. S. Dhomse, Mark Weber, Carlo Arosio, Wuhu Feng, and John P. Burrows
Atmos. Chem. Phys., 19, 767–783, https://doi.org/10.5194/acp-19-767-2019, https://doi.org/10.5194/acp-19-767-2019, 2019
Short summary
Short summary
In this study we analysed ozone changes in the tropical mid-stratosphere as observed by the SCIAMACHY instrument during 2004–2012. We used simulations from TOMCAT model with different chemical and dynamical forcings to reveal primary causes of ozone changes. We also considered measured NO2 and modelled NOx, NOx, and N2O data. With modelled AoA data we identified seasonal changes in the upwelling speed and explained how those changes affect N2O chemistry which leads to observed ozone changes.
Debora Griffin, Kaley A. Walker, Ingo Wohltmann, Sandip S. Dhomse, Markus Rex, Martyn P. Chipperfield, Wuhu Feng, Gloria L. Manney, Jane Liu, and David Tarasick
Atmos. Chem. Phys., 19, 577–601, https://doi.org/10.5194/acp-19-577-2019, https://doi.org/10.5194/acp-19-577-2019, 2019
Short summary
Short summary
Ozone in the stratosphere is important to protect the Earth from UV radiation. Using measurements taken by the Atmospheric Chemistry Experiment satellite between 2005 and 2013, we examine different methods to calculate the ozone loss in the high Arctic and establish the altitude at which most of the ozone is destroyed. Our results show that the different methods agree within the uncertainties. Recommendations are made on which methods are most appropriate to use.
Jiali Luo, Laura L. Pan, Shawn B. Honomichl, John W. Bergman, William J. Randel, Gene Francis, Cathy Clerbaux, Maya George, Xiong Liu, and Wenshou Tian
Atmos. Chem. Phys., 18, 12511–12530, https://doi.org/10.5194/acp-18-12511-2018, https://doi.org/10.5194/acp-18-12511-2018, 2018
Short summary
Short summary
We analyze upper tropospheric CO and O3 using satellite data from limb-viewing (MLS) and nadir-viewing (IASI and OMI) sensors, together with dynamical variables, to examine how the two types of data complement each other in representing the chemical variability associated with the day-to-day dynamical variability in the Asian summer monsoon anticyclone. The results provide new observational evidence of eddy shedding in upper tropospheric CO distribution.
Richard S. Stolarski, Anne R. Douglass, and Susan E. Strahan
Atmos. Chem. Phys., 18, 5691–5697, https://doi.org/10.5194/acp-18-5691-2018, https://doi.org/10.5194/acp-18-5691-2018, 2018
Short summary
Short summary
Detecting trends in short data sets of stratospheric molecules is difficult because of variability due to dynamical fluctuations. We suggest that one way around this difficulty is using the measurements of one molecule to remove dynamical variability from the measurements of another molecule. We illustrate this using Aura MLS measurements of N2O to help us sort out issues in the determination of trends in HCl. This shows that HCl is decreasing throughout the middle stratosphere as expected.
Erkki Kyrölä, Monika E. Andersson, Pekka T. Verronen, Marko Laine, Simo Tukiainen, and Daniel R. Marsh
Atmos. Chem. Phys., 18, 5001–5019, https://doi.org/10.5194/acp-18-5001-2018, https://doi.org/10.5194/acp-18-5001-2018, 2018
Short summary
Short summary
In this work we compare three key constituents of the middle atmosphere (ozone, NO2, and NO3) from the GOMOS satellite instrument with the WACCM model. We find that in the stratosphere (below 50 km) ozone differences are very small, but in the mesosphere large deviations are found. GOMOS and WACCM NO2 agree reasonably well except in the polar areas. These differences can be connected to the solar particle storms. For NO3, WACCM results agree with GOMOS with a very high correlation.
Martine De Mazière, Anne M. Thompson, Michael J. Kurylo, Jeannette D. Wild, Germar Bernhard, Thomas Blumenstock, Geir O. Braathen, James W. Hannigan, Jean-Christopher Lambert, Thierry Leblanc, Thomas J. McGee, Gerald Nedoluha, Irina Petropavlovskikh, Gunther Seckmeyer, Paul C. Simon, Wolfgang Steinbrecht, and Susan E. Strahan
Atmos. Chem. Phys., 18, 4935–4964, https://doi.org/10.5194/acp-18-4935-2018, https://doi.org/10.5194/acp-18-4935-2018, 2018
Short summary
Short summary
This paper serves as an introduction to the special issue "Twenty-five years of operations of the Network for the Detection of Atmospheric Composition Change (NDACC)". It describes the origins of the network, its actual status, and some perspectives for its future evolution in the context of atmospheric sciences.
Gaétane Ronsmans, Catherine Wespes, Daniel Hurtmans, Cathy Clerbaux, and Pierre-François Coheur
Atmos. Chem. Phys., 18, 4403–4423, https://doi.org/10.5194/acp-18-4403-2018, https://doi.org/10.5194/acp-18-4403-2018, 2018
Short summary
Short summary
The paper aims at understanding the variability of nitric acid (HNO3) in the stratosphere; 9-year time series of IASI measurements are analysed and, for the first time for HNO3, fitted with regression models in order to identify the factors at play. It was found that the annual variability is the main driver and that the polar stratospheric clouds influence greatly HNO3 variability at polar latitudes. The results show the potential of such analyses to better understand the polar processes.
Mark Weber, Melanie Coldewey-Egbers, Vitali E. Fioletov, Stacey M. Frith, Jeannette D. Wild, John P. Burrows, Craig S. Long, and Diego Loyola
Atmos. Chem. Phys., 18, 2097–2117, https://doi.org/10.5194/acp-18-2097-2018, https://doi.org/10.5194/acp-18-2097-2018, 2018
Short summary
Short summary
This paper commemorates the 30-year anniversary of the initial signing of the Montreal Protocol (MP) on substances that deplete the ozone layer. The MP is so far successful in reducing ozone-depleting substances, and total ozone decline was successfully stopped by the late 1990s. Total ozone levels have been mostly stable since then. In some regions, barely significant upward trends are observed that suggest an emergence into the expected ozone recovery phase.
Robert P. Damadeo, Joseph M. Zawodny, Ellis E. Remsberg, and Kaley A. Walker
Atmos. Chem. Phys., 18, 535–554, https://doi.org/10.5194/acp-18-535-2018, https://doi.org/10.5194/acp-18-535-2018, 2018
Short summary
Short summary
An ozone trend analysis that compensates for sampling biases is applied to sparsely sampled occultation data sets. International assessments have noted deficiencies in past trend analyses and this work addresses those sources of uncertainty. The nonuniform sampling patterns in data sets and drifts between data sets can affect derived recovery trends by up to 2 % decade−1. The limitations inherent to all techniques are also described and a potential path forward towards resolution is presented.
Gerald Wetzel, Hermann Oelhaf, Michael Höpfner, Felix Friedl-Vallon, Andreas Ebersoldt, Thomas Gulde, Sebastian Kazarski, Oliver Kirner, Anne Kleinert, Guido Maucher, Hans Nordmeyer, Johannes Orphal, Roland Ruhnke, and Björn-Martin Sinnhuber
Atmos. Chem. Phys., 17, 14631–14643, https://doi.org/10.5194/acp-17-14631-2017, https://doi.org/10.5194/acp-17-14631-2017, 2017
Short summary
Short summary
We report the first stratospheric measurements of the diurnal variation in the inorganic bromine (Bry) reservoir species BrONO2 around sunrise and sunset. The main goal of these observations was to check the current understanding of stratospheric bromine chemistry and to estimate the amount of lower-stratospheric Bry. The calculated temporal variation in BrONO2 largely reproduces the balloon-borne observations. The amount of Bry was estimated to be about 21–25 pptv in the lower stratosphere.
Cited articles
Alfred Wegener Institute: Ozone data set, available at: ftp://ftp.cpc.ncep.noaa.gov/ndacc/station/nyalsund/ames/o3sonde/, last access: 22 March 2018.
Brakebusch, M., Randall, C. E., Kinnison, D. E., Tilmes, S., Santee, M. L., and Manney, G. L.: Evaluation of whole atmosphere community climate model simulations of ozone during Arctic winter 2004–2005, J. Geophys. Res.-Atmos., 118, 2673–2688, https://doi.org/10.1002/jgrd.50226, 2013.
Chapman, S.: A theory of upper-atmospheric ozone, Memories R. Meteorol. Soc., 3, 103–125, 1930.
Collins, W. D., Rasch, P. J., Boville, B. A., Hack, J. J., McCaa, J. R., Williamson, D. L., Briegleb, B. P., Bitz, C. M., Lin, S.-J., and Zhang, M.: The formulation and atmospheric simulation of the Community Atmosphere Model version 3 (CAM3), J. Climate, 19, 2144–2161, 2006.
Connor, B. J., Siskind, D. E., Tsou, J. J., Parrish, A., and Remsberg, E. E.: Ground-based microwave observations of ozone in the upper stratosphere and mesosphere, J. Geophys. Res., 99, 16757–16770, 1994.
Emmons, L. K., Walters, S., Hess, P. G., Lamarque, J.-F., Pfister, G. G., Fillmore, D., Granier, C., Guenther, A., Kinnison, D., Laepple, T., Orlando, J., Tie, X., Tyndall, G., Wiedinmyer, C., Baughcum, S. L., and Kloster, S.: Description and evaluation of the Model for Ozone and Related chemical Tracers, version 4 (MOZART-4), Geosci. Model Dev., 3, 43–67, https://doi.org/10.5194/gmd-3-43-2010, 2010.
Eriksson, P., Jiménez, C., and Buehler, S. A.: Qpack, a general tool for instrument simulation and retrieval work, J. Quant. Spectrosc. Ra., 91, 47–64, https://doi.org/10.1016/j.jqsrt.2004.05.050, 2005.
Eriksson, P., Buehler, S. A., Davis, C. P., Emde, C., and Lemke, O.: ARTS, the atmospheric radiative transfer simulator, version 2, J. Quant. Spectrosc. Ra., 112, 1551–1558, https://doi.org/10.1016/j.jqsrt.2011.03.001, 2011.
Fernandez, S., Murk, A., and Kämpfer, N.: GROMOS-C, a novel ground-based microwave radiometer for ozone measurement campaigns, Atmos. Meas. Tech., 8, 2649–2662, https://doi.org/10.5194/amt-8-2649-2015, 2015.
Fernandez, S., Rüfenacht, R., Kämpfer, N., Portafaix, T., Posny, F., and Payen, G.: Results from the validation campaign of the ozone radiometer GROMOS-C at the NDACC station of Réunion island, Atmos. Chem. Phys., 16, 7531–7543, https://doi.org/10.5194/acp-16-7531-2016, 2016.
Froidevaux, L., Jiang, Y. B., Lambert, A., Livesey, N. J., Read, W. G., Waters, J. W., Browell, E. V., Hair, J. W., Avery, M. A., McGee, T. J., Twigg, L. W., Sumnicht, G. K., Jucks, K. W., Margitan, J. J., Sen, B., Stachnik, R. A., Toon, G. C., Bernath, P. F., Boone, C. D., Walker, K. A., Filipiak, M. J., Harwood, R. S., Fuller, R. A., Manney, G. L., Schwartz, M. J., Daffer, W. H., Drouin, B. J., Cofield, R. E., Cuddy, D. T., Jarnot, R. F., Knosp, B. W., Perun, V. S., Snyder, W. V., Stek, P. C., Thurstans, R. P., and Wagner, P. A.: Validation of Aura Microwave Limb Sounder stratospheric ozone measurements, J. Geophys. Res., 113, D15S20, https://doi.org/10.1029/2007JD008771, 2008.
Haefele, A., Hocke, K., Kämpfer, N., Keckhut, P., Marchand, M., Bekki, S., Morel, B., Egorova, T., and Rozanov, E.: Diurnal changes in middle atmospheric H2O and O3: observations in the Alpine region and climate models, J. Geophys. Res., 113, D17303, https://doi.org/10.1029/2008JD009892, 2008.
Hartogh, P., Jarchow, C., Sonnemann, G. R., and Grygalashvyly, M.: On the spatiotemporal behavior of ozone within the upper mesosphere/mesopause region under nearly polar night conditions, J. Geophys. Res., 109, D18303, https://doi.org/10.1029/2004JD004576, 2004.
Hoffmann, C. G., Kinnison, D. E., Garcia, R. R., Palm, M., Notholt, J., Raffalski, U., and Hochschild, G.: CO at 40–80 km above Kiruna observed by the ground-based microwave radiometer KIMRA and simulated by the Whole Atmosphere Community Climate Model, Atmos. Chem. Phys., 12, 3261–3271, https://doi.org/10.5194/acp-12-3261-2012, 2012.
Huang, F. T., Mayr, H. G., Russell, J. M. I., and Mlynczak, M. G.: Ozone diurnal variations in the stratosphere and lower mesosphere, based on measurements from SABER on TIMED, J. Geophys. Res., 115, D24308, https://doi.org/10.1029/2010JD014484, 2010.
Kunz, A., Pan, L. L., Konopka, P., Kinnison, D. E., and Tilmes, S.: Chemical and dynamical discontinuity at the extratropical tropopause based on START08 and WACCM analyses, J. Geophys. Res., 116, D24302, https://doi.org/10.1029/2011JD016686, 2011.
Lamarque, J.-F., Emmons, L. K., Hess, P. G., Kinnison, D. E., Tilmes, S., Vitt, F., Heald, C. L., Holland, E. A., Lauritzen, P. H., Neu, J., Orlando, J. J., Rasch, P. J., and Tyndall, G. K.: CAM-chem: description and evaluation of interactive atmospheric chemistry in the Community Earth System Model, Geosci. Model Dev., 5, 369–411, https://doi.org/10.5194/gmd-5-369-2012, 2012.
Liebe, H. J., Hufford, G. A., and Cotton, M. G.: Propagation modeling of moist air and suspended water/ice particles at frequencies below 1000 GHz, in: Proc. AGARD 52nd Spec. Meet. EM Wave Propag. Panel, Palma De Maiorca, Spain, 3.1–3.10, 1993.
Lobsiger, E. and Künzi, K. F.: Night-time increase of mesospheric ozone measured with ground-based microwave radiometry, J. Atmos. Terr. Phys., 48, 1153–1158, 1986.
Manney, G. L. and Lawrence, Z. D.: The major stratospheric final warming in 2016: dispersal of vortex air and termination of Arctic chemical ozone loss, Atmos. Chem. Phys., 16, 15371–15396, https://doi.org/10.5194/acp-16-15371-2016, 2016.
Marsh, D., Smith, A., Brasseur, G., Kaufmann, M., and Grossmann, K.: The existence of a tertiary ozone maximum in the high-latitude middle mesosphere, Geophys. Res. Lett., 28, 4531–4534, https://doi.org/10.1029/2001GL013791, 2001.
NASA: MLS ozone sonde: available at: MLS ozone data set, available at: https://acdisc.gesdisc.eosdis.nasa.gov/data/Aura_MLS_Level2/ML2O3.004/, last access: 22 March 2018.
Palm, M., Hoffmann, C. G., Golchert, S. H. W., and Notholt, J.: The ground-based MW radiometer OZORAM on Spitsbergen – description and status of stratospheric and mesospheric O3-measurements, Atmos. Meas. Tech., 3, 1533–1545, https://doi.org/10.5194/amt-3-1533-2010, 2010.
Palm, M., Golchert, S. H. W., Sinnhuber, M., Hochschild, G., and Notholt, J.: Influence of solar radiation on the diurnal and seasonal variability of O3 and H2O in the stratosphere and lower mesosphere based on continuous observations in the tropics and the high Arctic, in: Climate and Weather of the Sun-Earth System, edited by: Lübken, F.-J., Springer Netherlands, Dordrecht, 125–147, https://doi.org/10.1007/978-94-007-4348-9_8, 2013.
Parrish, A., Boyd, I. S., Nedoluha, G. E., Bhartia, P. K., Frith, S. M., Kramarova, N. A., Connor, B. J., Bodeker, G. E., Froidevaux, L., Shiotani, M., and Sakazaki, T.: Diurnal variations of stratospheric ozone measured by ground-based microwave remote sensing at the Mauna Loa NDACC site: measurement validation and GEOSCCM model comparison, Atmos. Chem. Phys., 14, 7255–7272, https://doi.org/10.5194/acp-14-7255-2014, 2014.
Penfield, H., Litvak, M. M., Gottlieb, C. A., and Lilley, A. E.: Mesospheric ozone measured from ground-based millimeter wave observations, J. Geophys. Res., 81, 6115–6120, 1976.
Ricaud, P., de La Noe, J., Connor, B. J., Froidevaux, L., Waters, J. W., Harwood, R. S., MacKenzie, I. A., and Peckham, G. E.: Diurnal variability of mesospheric ozone as measured by the UARS microwave limb sounder instrument: theoretical and ground-based validations, J. Geophys. Res., 101, 10077–10089, 1996.
Rienecker, M., Suarez, M., Todling, R., Bacmeister, J., Takacs, L., Liu, H.-C., Gu, W., Sienkiewicz, M., Koster, R., Gelaro, R., Stajner, I., and Nielsen, J.: The GEOS-5 Data Assimilation System – Documentation of Versions 5.0.1, 5.1.0, and 5.2.0, Tech. Rep. December, NASA Goddard Space Flight Center, Greenbelt, available at: https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20120011955.pdf, 2008.
Rodgers, C. D.: Retrieval of atmospheric temperature and composition from remote measurements of thermal radiation, Rev. Geophys. Space. Ge., 14, 609–624, https://doi.org/10.1029/RG014i004p00609, 1976.
Rüfenacht, R., Kämpfer, N., and Murk, A.: First middle-atmospheric zonal wind profile measurements with a new ground-based microwave Doppler-spectro-radiometer, Atmos. Meas. Tech., 5, 2647–2659, https://doi.org/10.5194/amt-5-2647-2012, 2012.
Sakazaki, T., Fujiwara, M., Mitsuda, C., Imai, K., Manago, N., Naito, Y., Nakamura, T., Akiyoshi, H., Kinnison, D., Sano, T., Suzuki, M., and Shiotani, M.: Diurnal ozone variations in the stratosphere revealed in observations from the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) on board the International Space Station (ISS), J. Geophys. Res.-Atmos., 118, 2991–3006, https://doi.org/10.1002/jgrd.50220, 2013.
Schanz, A., Hocke, K., and Kämpfer, N.: Daily ozone cycle in the stratosphere: global, regional and seasonal behaviour modelled with the Whole Atmosphere Community Climate Model, Atmos. Chem. Phys., 14, 7645–7663, https://doi.org/10.5194/acp-14-7645-2014, 2014a.
Schanz, A., Hocke, K., Kämpfer, N., Chabrillat, S., Inness, A., Palm, M., Notholt, J., Boyd, I., Parrish, A., and Kasai, Y.: The diurnal variation in stratospheric ozone from the MACC reanalysis, the ERA-Interim reanalysis, WACCM and Earth observation data: characteristics and intercomparison, Atmos. Chem. Phys. Discuss., 14, 32667–32708, https://doi.org/10.5194/acpd-14-32667-2014, 2014b.
Sinnhuber, B.-M., Müller, R., Langer, J., Bovensmann, H., Eyring, V., Klein, U., Trentmann, J., Burrows, J. P., and Künzi, K. F.: Interpretation of mid-stratospheric Arctic Ozone measurements using a photochemical box-model, J. Atmos. Chem., 34, 281–290, 1999.
Sofieva, V. F., Kyrölä, E., Verronen, P. T., Seppälä, A., Tamminen, J., Marsh, D. R., Smith, A. K., Bertaux, J.-L., Hauchecorne, A., Dalaudier, F., Fussen, D., Vanhellemont, F., Fanton d'Andon, O., Barrot, G., Guirlet, M., Fehr, T., and Saavedra, L.: Spatio-temporal observations of the tertiary ozone maximum, Atmos. Chem. Phys., 9, 4439–4445, https://doi.org/10.5194/acp-9-4439-2009, 2009.
Studer, S., Hocke, K., Schanz, A., Schmidt, H., and Kämpfer, N.: A climatology of the diurnal variations in stratospheric and mesospheric ozone over Bern, Switzerland, Atmos. Chem. Phys., 14, 5905–5919, https://doi.org/10.5194/acp-14-5905-2014, 2014.
Tweedy, O. V., Limpasuvan, V., Orsolini, Y. J., Smith, A. K., Garcia, R. R., Kinnison, D., Randall, C. E., Kvissel, O.-K., Stordal, F., Harvey, V. L., and Chandran, A.: Nighttime secondary ozone layer during major stratospheric sudden warmings in specified-dynamics WACCM, J. Geophys. Res.-Atmos., 118, 8346–8358, https://doi.org/10.1002/jgrd.50651, 2013.
University of Bern: GROMOS-C: Ozone data set, available at: ftp://ftp.cpc.ncep.noaa.gov/ndacc/station/nyalsund/hdf/mwave/, last access: 22 March 2018.
University of Bremen: OZORAM: available at: ftp://ftp.cpc.ncep.noaa.gov/ndacc/station/nyalsund/hdf/mwave/, last access: 22 March 2018.
Vaughan, G.: Diurnal variation of mesospheric ozone, Nature, 296, 133–135, 1982.
Waters, J. W., Froidevaux, L., Harwood, R. S., Jarnot, R. F., Pickett, H. M., Read, W. G., Siegel, P. H., Cofield, R. E., Filipiak, M. J., Flower, D. A., Holden, J. R., Lau, G. K., Livesey, N. J., Manney, G. L., Pumphrey, H. C., Santee, M. L., Wu, D. L., Cuddy, D. T., Lay, R. R., Loo, M. S., Perun, V. S., Schwartz, M. J., Stek, P. C., Thurstans, R. P., Boyles, M. A., Chandra, K. M., Chavez, M. C., Chen, G.-S., Chudasama, B. V., Dodge, R., Fuller, R. A., Girard, M. A., Jiang, J. H., Jiang, Y., Knosp, B. W., Labelle, R. C., Lam, J. C., Lee, K. A., Miller, D., Oswald, J. E., Patel, N. C., Pukala, D. M., Quintero, O., Scaff, D. M., Snyder, W. V., Tope, M. C., Wagner, P. A., and Walch, M. J.: The Earth Observing System Microwave Limb Sounder (EOS MLS) on the Aura Satellite, IEEE T. Geosci. Remote, 44, 1075–1092, 2006.
Wilson, W. J. and Schwartz, P. R.: Diurnal variations of mesospheric ozone using millimeter-wave measurements, J. Geophys. Res., 86, 7385–7388, 1981.
Zommerfelds, W. C., Künzi, K. F., Summers, M. E., Bevilacqua, R. M., Strobel, D. F., Allen, M., and Sawchuck, W.: Diurnal variations of mesospheric ozone obtained by ground-based microwave radiometry, J. Geophys. Res., 94, 12819–12832, 1989.
Short summary
We present 1 year of ozone measurements form two ground-based microwave radiometers located at Ny-Ålesund, Svalbard. The ozone measurements cover an altitude range of 25–70 km altitude and have a high time resolution of 1–2 h. With these datasets and model data a comprehensive analysis of the ozone diurnal cycle in the Arctic is performed for the different insolation conditions throughout the year. In the stratosphere we find a diurnal cycle which persists over the whole polar day.
We present 1 year of ozone measurements form two ground-based microwave radiometers located at...
Special issue
Altmetrics
Final-revised paper
Preprint