Articles | Volume 19, issue 7
https://doi.org/10.5194/acp-19-4235-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-19-4235-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
03 Apr 2019
Research article |
| 03 Apr 2019
| 03 Apr 2019
Indications for a potential synchronization between the phase evolution of the Madden–Julian oscillation and the solar 27-day cycle
Christoph G. Hoffmann
CORRESPONDING AUTHOR
Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald, Germany
Christian von Savigny
Institute of Physics, University of Greifswald, Felix-Hausdorff-Str. 6, 17489 Greifswald, Germany
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Christian von Savigny, Anna Lange, Christoph G. Hoffmann, and Alexei Rozanov
Atmos. Chem. Phys., 24, 2415–2422, https://doi.org/10.5194/acp-24-2415-2024, https://doi.org/10.5194/acp-24-2415-2024, 2024
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It is well known that volcanic eruptions strongly affect the colours of the twilight sky. Typically, volcanic eruptions lead to enhanced reddish and violet twilight colours. In rare cases, however, volcanic eruptions can also lead to green sunsets. This study provides an explanation for the occurrence of these unusual green sunsets based on simulations with a radiative transfer model. Green volcanic sunsets require a sufficient stratospheric aerosol optical depth and specific aerosol sizes.
Christoph G. Hoffmann, Lena G. Buth, and Christian von Savigny
Atmos. Chem. Phys., 23, 12781–12799, https://doi.org/10.5194/acp-23-12781-2023, https://doi.org/10.5194/acp-23-12781-2023, 2023
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The Madden–Julian oscillation is an important feature of weather in the tropics. Although it is mainly active in the troposphere, we show that it systematically influences the air temperature in the layers above, up to about 100 km altitude and from pole to pole. We have linked this to another known far-reaching process, interhemispheric coupling. This is basic research on atmospheric couplings and variability but might also be of interest for intraseasonal weather forecasting models.
Christian von Savigny, Anna Lange, Anne Hemkendreis, Christoph G. Hoffmann, and Alexei Rozanov
Clim. Past, 18, 2345–2356, https://doi.org/10.5194/cp-18-2345-2022, https://doi.org/10.5194/cp-18-2345-2022, 2022
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This study investigates the possibility of inferring information on aerosol optical depth from photographs of historic paintings. The idea – which has been applied in previous studies – is very interesting because it would provide an archive of the atmospheric aerosol loading covering many centuries. We show that twilight colours depend not only on the aerosol optical thickness, but also on several other parameters, making a quantitative estimate of aerosol optical depth very difficult.
Sandra Wallis, Christoph Gregor Hoffmann, and Christian von Savigny
Ann. Geophys., 40, 421–431, https://doi.org/10.5194/angeo-40-421-2022, https://doi.org/10.5194/angeo-40-421-2022, 2022
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Although the 1991 eruption of Mt Pinatubo had a severe impact on Earth's climate, the effect of this event on the mesosphere is not well understood. We investigated satellite-borne temperature measurements from the HALOE instrument and found indications that a positive temperature anomaly is present in the tropical upper mesosphere at the beginning of the HALOE time series, which may be related to the eruption of Mt. Pinatubo.
Christian von Savigny and Christoph G. Hoffmann
Atmos. Meas. Tech., 13, 1909–1920, https://doi.org/10.5194/amt-13-1909-2020, https://doi.org/10.5194/amt-13-1909-2020, 2020
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Stratospheric sulfate aerosols increase the Earth's planetary albedo and can lead to significant surface cooling, for example in the aftermath of volcanic eruptions. Their particle size distribution, important for physical and chemical effects of these aerosols, is still not fully understood. The present paper proposes an explanation for systematic differences in aerosol particle size retrieved from measurements made in different measurement geometries and reported in earlier studies.
Piao Rong, Christian von Savigny, Chunmin Zhang, Christoph G. Hoffmann, and Michael J. Schwartz
Atmos. Chem. Phys., 20, 1737–1755, https://doi.org/10.5194/acp-20-1737-2020, https://doi.org/10.5194/acp-20-1737-2020, 2020
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We study the presence and characteristics of 27 d solar signatures in middle atmospheric temperature observed by the microwave limb sounder on NASA's Aura spacecraft. This is a highly interesting and significant subject because the physical and chemical mechanisms leading to these 27 d solar-driven signatures are, in many cases, not well understood. The analysis shows that highly significant 27 d solar signatures in middle atmospheric temperature are present at many altitudes and latitudes.
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
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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.
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
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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.
Sandra Wallis, Matthew DeLand, and Christian von Savigny
EGUsphere, https://doi.org/10.5194/egusphere-2024-2165, https://doi.org/10.5194/egusphere-2024-2165, 2024
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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The 2022 Hunga eruption emitted about 150 Tg H2O that partly reached the upper polar SH mesosphere in the beginning of 2024. Noctilucent clouds (NLC) did not show a clear perturbation in their occurrence frequency, but the slight increase from mid-January to February could potentially be caused by the additional H2O. It needs 2 years to reach the summer polar mesopause region, analogous to the 1883 Krakatau eruption that is argued to have caused the first sightings of NCLs.
Felix Wrana, Terry Deshler, Christian Löns, Larry W. Thomason, and Christian von Savigny
EGUsphere, https://doi.org/10.5194/egusphere-2024-2942, https://doi.org/10.5194/egusphere-2024-2942, 2024
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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There is a natural and globally occurring layer of small droplets (aerosols) in roughly 20 km altitude in the atmosphere. In this work, the size of these aerosols is calculated from satellite measurements for the years 2002 to 2005, which is important for the aerosols cooling effect on Earth's climate. These years are interesting, because there were no large volcanic eruptions that would change the background state of the aerosols. The results are compared to reliable balloon-borne measurements.
Christine Pohl, Felix Wrana, Alexei Rozanov, Terry Deshler, Elizaveta Malinina, Christian von Savigny, Landon A. Rieger, Adam E. Bourassa, and John P. Burrows
Atmos. Meas. Tech., 17, 4153–4181, https://doi.org/10.5194/amt-17-4153-2024, https://doi.org/10.5194/amt-17-4153-2024, 2024
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Knowledge of stratospheric aerosol characteristics is important for understanding chemical and climate aerosol feedbacks. Two particle size distribution parameters, the aerosol extinction coefficient and the effective radius, are obtained from SCIAMACHY limb observations. The aerosol characteristics show good agreement with independent data sets from balloon-borne and satellite observations. This data set expands the limited knowledge of stratospheric aerosol characteristics.
Christian von Savigny, Anna Lange, Christoph G. Hoffmann, and Alexei Rozanov
Atmos. Chem. Phys., 24, 2415–2422, https://doi.org/10.5194/acp-24-2415-2024, https://doi.org/10.5194/acp-24-2415-2024, 2024
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It is well known that volcanic eruptions strongly affect the colours of the twilight sky. Typically, volcanic eruptions lead to enhanced reddish and violet twilight colours. In rare cases, however, volcanic eruptions can also lead to green sunsets. This study provides an explanation for the occurrence of these unusual green sunsets based on simulations with a radiative transfer model. Green volcanic sunsets require a sufficient stratospheric aerosol optical depth and specific aerosol sizes.
Anna Lange, Alexei Rozanov, and Christian von Savigny
Atmos. Chem. Phys., 23, 14829–14839, https://doi.org/10.5194/acp-23-14829-2023, https://doi.org/10.5194/acp-23-14829-2023, 2023
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We were able to demonstrate quantitatively that the blue colour of the sky cannot be solely attributed to Rayleigh scattering. The influence of ozone on the blue colour of the sky is calculated for different viewing geometries, total ozone columns and an enhanced stratospheric aerosol scenario. Furthermore, the effects of polarisation, surface albedo and observer height are investigated.
John M. C. Plane, Jörg Gumbel, Konstantinos S. Kalogerakis, Daniel R. Marsh, and Christian von Savigny
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Christoph G. Hoffmann, Lena G. Buth, and Christian von Savigny
Atmos. Chem. Phys., 23, 12781–12799, https://doi.org/10.5194/acp-23-12781-2023, https://doi.org/10.5194/acp-23-12781-2023, 2023
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The Madden–Julian oscillation is an important feature of weather in the tropics. Although it is mainly active in the troposphere, we show that it systematically influences the air temperature in the layers above, up to about 100 km altitude and from pole to pole. We have linked this to another known far-reaching process, interhemispheric coupling. This is basic research on atmospheric couplings and variability but might also be of interest for intraseasonal weather forecasting models.
Felix Wrana, Ulrike Niemeier, Larry W. Thomason, Sandra Wallis, and Christian von Savigny
Atmos. Chem. Phys., 23, 9725–9743, https://doi.org/10.5194/acp-23-9725-2023, https://doi.org/10.5194/acp-23-9725-2023, 2023
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The stratospheric aerosol layer is a naturally occurring and permanent layer of aerosol, in this case very small droplets of mostly sulfuric acid and water, that has a cooling effect on our climate. To quantify this effect and for our general understanding of stratospheric microphysical processes, knowledge of the size of those aerosol particles is needed. Using satellite measurements and atmospheric models we show that some volcanic eruptions can lead to on average smaller aerosol sizes.
Sandra Wallis, Hauke Schmidt, and Christian von Savigny
Atmos. Chem. Phys., 23, 7001–7014, https://doi.org/10.5194/acp-23-7001-2023, https://doi.org/10.5194/acp-23-7001-2023, 2023
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Strong volcanic eruptions are able to alter the temperature and the circulation of the middle atmosphere. This study simulates the atmospheric response to an idealized strong tropical eruption and focuses on the impact on the mesosphere. The simulations show a warming of the polar summer mesopause in the first November after the eruption. Our study indicates that this is mainly due to dynamical coupling in the summer hemisphere with a potential contribution from interhemispheric coupling.
Christian von Savigny, Anna Lange, Anne Hemkendreis, Christoph G. Hoffmann, and Alexei Rozanov
Clim. Past, 18, 2345–2356, https://doi.org/10.5194/cp-18-2345-2022, https://doi.org/10.5194/cp-18-2345-2022, 2022
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This study investigates the possibility of inferring information on aerosol optical depth from photographs of historic paintings. The idea – which has been applied in previous studies – is very interesting because it would provide an archive of the atmospheric aerosol loading covering many centuries. We show that twilight colours depend not only on the aerosol optical thickness, but also on several other parameters, making a quantitative estimate of aerosol optical depth very difficult.
Sandra Wallis, Christoph Gregor Hoffmann, and Christian von Savigny
Ann. Geophys., 40, 421–431, https://doi.org/10.5194/angeo-40-421-2022, https://doi.org/10.5194/angeo-40-421-2022, 2022
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Although the 1991 eruption of Mt Pinatubo had a severe impact on Earth's climate, the effect of this event on the mesosphere is not well understood. We investigated satellite-borne temperature measurements from the HALOE instrument and found indications that a positive temperature anomaly is present in the tropical upper mesosphere at the beginning of the HALOE time series, which may be related to the eruption of Mt. Pinatubo.
Anna Lange, Gerd Baumgarten, Alexei Rozanov, and Christian von Savigny
Ann. Geophys., 40, 407–419, https://doi.org/10.5194/angeo-40-407-2022, https://doi.org/10.5194/angeo-40-407-2022, 2022
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We investigate the influence of different parameters on the colour of noctilucent clouds (highest clouds in the atmosphere), using radiative transfer calculations. We determined the effect of the particle size, optical depth, single scattering/multiple scattering and ozone. For sufficiently large optical depth and for specific viewing geometries, ozone plays only a minor role in the blueish colour of noctilucent clouds (new result).
Mireia Papke Chica, Valerian Hahn, Tiziana Braeuer, Elena de la Torre Castro, Florian Ewald, Mathias Gergely, Simon Kirschler, Luca Bugliaro Goggia, Stefanie Knobloch, Martina Kraemer, Johannes Lucke, Johanna Mayer, Raphael Maerkl, Manuel Moser, Laura Tomsche, Tina Jurkat-Witschas, Martin Zoeger, Christian von Savigny, and Christiane Voigt
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-255, https://doi.org/10.5194/acp-2022-255, 2022
Preprint withdrawn
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The mixed-phase temperature regime in convective clouds challenges our understanding of microphysical and radiative cloud properties. We provide a rare and unique dataset of aircraft in situ measurements in a strong mid-latitude convective system. We find that mechanisms initiating ice nucleation and growth strongly depend on temperature, relative humidity, and vertical velocity and variate within the measured system, resulting in altitude dependent changes of the cloud liquid and ice fraction.
Julia Koch, Adam Bourassa, Nick Lloyd, Chris Roth, and Christian von Savigny
Atmos. Chem. Phys., 22, 3191–3202, https://doi.org/10.5194/acp-22-3191-2022, https://doi.org/10.5194/acp-22-3191-2022, 2022
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The mesopause, the region of the earth's atmosphere between 85 and 100 km, is hard to access by direct measurements. Therefore we look for parameters that can be measured using satellite or ground-based measurements. In this study we researched sodium airglow, a phenomenon that occurs when sodium atoms are excited by chemical reactions. We compared satellite measurements of the airglow and resulting sodium concentration profiles to gain a better understanding of the sodium in that region.
Elizaveta Malinina, Alexei Rozanov, Ulrike Niemeier, Sandra Wallis, Carlo Arosio, Felix Wrana, Claudia Timmreck, Christian von Savigny, and John P. Burrows
Atmos. Chem. Phys., 21, 14871–14891, https://doi.org/10.5194/acp-21-14871-2021, https://doi.org/10.5194/acp-21-14871-2021, 2021
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In the paper, changes in the stratospheric aerosol loading after the 2018 Ambae eruption were analyzed using OMPS-LP observations. The eruption was also simulated with the MAECHAM5-HAM global climate model. Generally, the model and observations agree very well. We attribute the good consistency of the results to a precisely determined altitude and mass of the volcanic injection, as well as nudging of the meteorological data. The radiative forcing from the eruption was estimated to be −0.13 W m−2.
Nellie Wullenweber, Anna Lange, Alexei Rozanov, and Christian von Savigny
Clim. Past, 17, 969–983, https://doi.org/10.5194/cp-17-969-2021, https://doi.org/10.5194/cp-17-969-2021, 2021
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This study investigates the physical processes leading to the rare phenomenon of the sun appearing blue or green. The phenomenon is caused by anomalous scattering by, e.g., volcanic or forest fire aerosols. Unlike most other studies, our study includes a full treatment of the effect of Rayleigh scattering on the colour of the sun. We investigate different factors and revisit a historic example, i.e. the Canadian forest fires in 1950, that led to blue sun events in different European countries.
Felix Wrana, Christian von Savigny, Jacob Zalach, and Larry W. Thomason
Atmos. Meas. Tech., 14, 2345–2357, https://doi.org/10.5194/amt-14-2345-2021, https://doi.org/10.5194/amt-14-2345-2021, 2021
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In this paper, we describe a new method for calculating the size of naturally occurring droplets (aerosols) made mostly of sulfuric acid and water that can be found roughly at 20 km altitude in the atmosphere. We use data from the instrument SAGE III/ISS that is mounted on the International Space Station. We show that our method works well, and that the size parameters we calculate are reasonable and can be a valuable addition for a better understanding of aerosols and their effect on climate.
Larry W. Thomason, Mahesh Kovilakam, Anja Schmidt, Christian von Savigny, Travis Knepp, and Landon Rieger
Atmos. Chem. Phys., 21, 1143–1158, https://doi.org/10.5194/acp-21-1143-2021, https://doi.org/10.5194/acp-21-1143-2021, 2021
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Measurements of the impact of volcanic eruptions on stratospheric aerosol loading by space-based instruments show show a fairly well-behaved relationship between the magnitude and the apparent changes to aerosol size over several orders of magnitude. This directly measured relationship provides a unique opportunity to verify the performance of interactive aerosol models used in climate models.
Lukas O. Muser, Gholam Ali Hoshyaripour, Julia Bruckert, Ákos Horváth, Elizaveta Malinina, Sandra Wallis, Fred J. Prata, Alexei Rozanov, Christian von Savigny, Heike Vogel, and Bernhard Vogel
Atmos. Chem. Phys., 20, 15015–15036, https://doi.org/10.5194/acp-20-15015-2020, https://doi.org/10.5194/acp-20-15015-2020, 2020
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Volcanic aerosols endanger aircraft and thus disrupt air travel globally. For aviation safety, it is vital to know the location and lifetime of such aerosols in the atmosphere. Here we show that the interaction of volcanic particles with each other eventually reduces their atmospheric lifetime. Moreover, we demonstrate that sunlight heats these particles, which lifts them several kilometers in the atmosphere. These findings support a more reliable forecast of volcanic aerosol dispersion.
Thomas von Clarmann, Douglas A. Degenstein, Nathaniel J. Livesey, Stefan Bender, Amy Braverman, André Butz, Steven Compernolle, Robert Damadeo, Seth Dueck, Patrick Eriksson, Bernd Funke, Margaret C. Johnson, Yasuko Kasai, Arno Keppens, Anne Kleinert, Natalya A. Kramarova, Alexandra Laeng, Bavo Langerock, Vivienne H. Payne, Alexei Rozanov, Tomohiro O. Sato, Matthias Schneider, Patrick Sheese, Viktoria Sofieva, Gabriele P. Stiller, Christian von Savigny, and Daniel Zawada
Atmos. Meas. Tech., 13, 4393–4436, https://doi.org/10.5194/amt-13-4393-2020, https://doi.org/10.5194/amt-13-4393-2020, 2020
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Remote sensing of atmospheric state variables typically relies on the inverse solution of the radiative transfer equation. An adequately characterized retrieval provides information on the uncertainties of the estimated state variables as well as on how any constraint or a priori assumption affects the estimate. This paper summarizes related techniques and provides recommendations for unified error reporting.
Christian von Savigny and Christoph G. Hoffmann
Atmos. Meas. Tech., 13, 1909–1920, https://doi.org/10.5194/amt-13-1909-2020, https://doi.org/10.5194/amt-13-1909-2020, 2020
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Stratospheric sulfate aerosols increase the Earth's planetary albedo and can lead to significant surface cooling, for example in the aftermath of volcanic eruptions. Their particle size distribution, important for physical and chemical effects of these aerosols, is still not fully understood. The present paper proposes an explanation for systematic differences in aerosol particle size retrieved from measurements made in different measurement geometries and reported in earlier studies.
Olexandr Lednyts'kyy and Christian von Savigny
Atmos. Chem. Phys., 20, 2221–2261, https://doi.org/10.5194/acp-20-2221-2020, https://doi.org/10.5194/acp-20-2221-2020, 2020
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Atomic oxygen is a chemically active trace gas and a critical component of the energy balance of the mesosphere and lower thermosphere (MLT). By sequentially applying continuity equations of low degree, a new model representing the airglow and photochemistry of oxygen in the MLT is implemented, enabling comparisons with airglow observations at each step. The most effective data sets required to derive the abundance of atomic oxygen are the O2 atmospheric band emission, temperature, N2 and O2.
Piao Rong, Christian von Savigny, Chunmin Zhang, Christoph G. Hoffmann, and Michael J. Schwartz
Atmos. Chem. Phys., 20, 1737–1755, https://doi.org/10.5194/acp-20-1737-2020, https://doi.org/10.5194/acp-20-1737-2020, 2020
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We study the presence and characteristics of 27 d solar signatures in middle atmospheric temperature observed by the microwave limb sounder on NASA's Aura spacecraft. This is a highly interesting and significant subject because the physical and chemical mechanisms leading to these 27 d solar-driven signatures are, in many cases, not well understood. The analysis shows that highly significant 27 d solar signatures in middle atmospheric temperature are present at many altitudes and latitudes.
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
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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.
Jacob Zalach, Christian von Savigny, Arvid Langenbach, Gerd Baumgarten, Franz-Josef Lübken, and Adam Bourassa
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2019-267, https://doi.org/10.5194/amt-2019-267, 2019
Revised manuscript not accepted
Arvid Langenbach, Gerd Baumgarten, Jens Fiedler, Franz-Josef Lübken, Christian von Savigny, and Jacob Zalach
Atmos. Meas. Tech., 12, 4065–4076, https://doi.org/10.5194/amt-12-4065-2019, https://doi.org/10.5194/amt-12-4065-2019, 2019
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Stratospheric aerosol backscatter ratios in the Arctic using Rayleigh, Mie and Raman backscattered signals were calculated. A backscatter ratio calculation during daytime was performed for the first time. Sharp aerosol layers thinner than 1 km over several days were observed. The seasonal cycle of stratospheric background aerosol in high latitudes including the summer months was calculated for the first time. Top altitude of the aerosol layer was found to reach up to 34 km, especially in summer.
Christian von Savigny, Dieter H. W. Peters, and Günter Entzian
Atmos. Chem. Phys., 19, 2079–2093, https://doi.org/10.5194/acp-19-2079-2019, https://doi.org/10.5194/acp-19-2079-2019, 2019
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This study investigates solar effects in radio reflection height observations in the ionospheric D region at an altitude of about 80 km at northern midlatitudes. The analyzed time series covers almost six solar cycles. Statistically significant solar 27-day and 11-year signatures are identified. However, the driving mechanisms are not fully understood. We also provide evidence for dynamical effects on the radio reflection heights with periods close to the solar rotational cycle.
Tilo Fytterer, Christian von Savigny, Martin Mlynczak, and Miriam Sinnhuber
Atmos. Chem. Phys., 19, 1835–1851, https://doi.org/10.5194/acp-19-1835-2019, https://doi.org/10.5194/acp-19-1835-2019, 2019
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A model was developed to derive night-time atomic oxygen (O(3P)) and atomic hydrogen (H) from satellite observations in the altitude region between 75 km and 100 km. Comparisons between the
best-fit modeland the measurements suggest that chemical reactions involving O2 and O(3P) might occur differently than is usually assumed in literature. This considerably affects the derived abundances of O(3P) and H, which in turn might influence air temperature and winds of the whole atmosphere.
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
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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 P. Langowski, Christian von Savigny, John P. Burrows, Didier Fussen, Erin C. M. Dawkins, Wuhu Feng, John M. C. Plane, and Daniel R. Marsh
Atmos. Meas. Tech., 10, 2989–3006, https://doi.org/10.5194/amt-10-2989-2017, https://doi.org/10.5194/amt-10-2989-2017, 2017
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Meteoric metals form metal layers in the upper atmosphere anandplay a role in the formation of middle-atmospheric clouds and aerosols. However, the total metal influx rate is not well known. Global Na datasets from measurements and a model are available, which had not been compared yet on a global scale until this paper. Overall the agreement is good, and many differences between measurements are also found in the model simulations. However, the modeled layer altitude is too low.
Kai-Uwe Eichmann, Luca Lelli, Christian von Savigny, Harjinder Sembhi, and John P. Burrows
Atmos. Meas. Tech., 9, 793–815, https://doi.org/10.5194/amt-9-793-2016, https://doi.org/10.5194/amt-9-793-2016, 2016
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Height-resolved limb radiance spectra of the satellite instrument SCIAMACHY are used to retrieve cloud top heights with a colour index method. Clouds are detectable from the lower to the uppermost troposphere. These cloud heights help to improve the trace gas retrieval for the upper troposphere and lower stratosphere. Comparisons with other data sets have shown good agreement. As clouds and aerosols are not distinguishable, lower stratospheric volcanic aerosol clouds are detected in some years.
M. P. Langowski, C. von Savigny, J. P. Burrows, V. V. Rozanov, T. Dunker, U.-P. Hoppe, M. Sinnhuber, and A. C. Aikin
Atmos. Meas. Tech., 9, 295–311, https://doi.org/10.5194/amt-9-295-2016, https://doi.org/10.5194/amt-9-295-2016, 2016
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An algorithm has been developed for the retrieval of sodium atom (Na) number density on a latitude and altitude grid from SCIAMACHY limb measurements of the Na resonance fluorescence (multiannual means 2008–2012). The Na layer peaks at 90 to 93 km altitude and has a FWHM of 5 to 15 km. A summer minimum in peak density and width is observed at high latitudes. At low latitudes, a semiannual oscillation is found. The results are compared with other measurements and models and agree well with these.
F. Ebojie, J. P. Burrows, C. Gebhardt, A. Ladstätter-Weißenmayer, C. von Savigny, A. Rozanov, M. Weber, and H. Bovensmann
Atmos. Chem. Phys., 16, 417–436, https://doi.org/10.5194/acp-16-417-2016, https://doi.org/10.5194/acp-16-417-2016, 2016
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The goal of this study is to determine the global and zonal changes in the tropospheric ozone data product derived from SCIAMACHY limb-nadir-matching (LNM) observations during the period 2003–2011.
Tropospheric O3 shows statistically significant increases over some regions of South Asia, the South American continent, Alaska, around Congo in Africa and over some continental outflows. Significant decrease in TOC is observed over some continents and oceans.
C. von Savigny, F. Ernst, A. Rozanov, R. Hommel, K.-U. Eichmann, V. Rozanov, J. P. Burrows, and L. W. Thomason
Atmos. Meas. Tech., 8, 5223–5235, https://doi.org/10.5194/amt-8-5223-2015, https://doi.org/10.5194/amt-8-5223-2015, 2015
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This article presents validation results for stratospheric aerosol extinction profiles retrieved from limb-scatter measurements with the SCIAMACHY instrument on the Envisat satellite. The SCIAMACHY retrievals are compared to co-located measurements with the SAGE II instrument. Very good agreement to within about 15% is found in a global average sense at altitudes above 15 km. The article also presents sample results on the global morphology of the stratospheric aerosol layer from 2003 to 2011.
O. Lednyts'kyy, C. von Savigny, K.-U. Eichmann, and M. G. Mlynczak
Atmos. Meas. Tech., 8, 1021–1041, https://doi.org/10.5194/amt-8-1021-2015, https://doi.org/10.5194/amt-8-1021-2015, 2015
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This paper deals with the retrieval of atomic oxygen concentration profiles in the Earth's upper mesosphere/lower thermosphere region from SCIAMACHY observations of oxygen green line airglow emissions. Atomic oxygen is one of the most important chemical constituents of this atmospheric region, and long-term satellite data sets are rare. The paper includes a detailed description of the retrieval algorithm, an error budget, validation results and some first scientific analyses.
M. P. Langowski, C. von Savigny, J. P. Burrows, W. Feng, J. M. C. Plane, D. R. Marsh, D. Janches, M. Sinnhuber, A. C. Aikin, and P. Liebing
Atmos. Chem. Phys., 15, 273–295, https://doi.org/10.5194/acp-15-273-2015, https://doi.org/10.5194/acp-15-273-2015, 2015
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Global concentration fields of Mg and Mg+ in the Earth's upper mesosphere and lower thermosphere (70-150km) are presented. These are retrieved from SCIAMACHY/Envisat satellite grating spectrometer measurements in limb viewing geometry between 2008 and 2012.
These were compared with WACCM-Mg model results and a large fraction of the available measurement results for these species, and an interpretation of the results is done. The variation of these species during NLC presence is discussed.
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
F. Ebojie, C. von Savigny, A. Ladstätter-Weißenmayer, A. Rozanov, M. Weber, K.-U. Eichmann, S. Bötel, N. Rahpoe, H. Bovensmann, and J. P. Burrows
Atmos. Meas. Tech., 7, 2073–2096, https://doi.org/10.5194/amt-7-2073-2014, https://doi.org/10.5194/amt-7-2073-2014, 2014
B. Hassler, I. Petropavlovskikh, J. Staehelin, T. August, P. K. Bhartia, C. Clerbaux, D. Degenstein, M. De Mazière, B. M. Dinelli, A. Dudhia, G. Dufour, S. M. Frith, L. Froidevaux, S. Godin-Beekmann, J. Granville, N. R. P. Harris, K. Hoppel, D. Hubert, Y. Kasai, M. J. Kurylo, E. Kyrölä, J.-C. Lambert, P. F. Levelt, C. T. McElroy, R. D. McPeters, R. Munro, H. Nakajima, A. Parrish, P. Raspollini, E. E. Remsberg, K. H. Rosenlof, A. Rozanov, T. Sano, Y. Sasano, M. Shiotani, H. G. J. Smit, G. Stiller, J. Tamminen, D. W. Tarasick, J. Urban, R. J. van der A, J. P. Veefkind, C. Vigouroux, T. von Clarmann, C. von Savigny, K. A. Walker, M. Weber, J. Wild, and J. M. Zawodny
Atmos. Meas. Tech., 7, 1395–1427, https://doi.org/10.5194/amt-7-1395-2014, https://doi.org/10.5194/amt-7-1395-2014, 2014
R. Hommel, K.-U. Eichmann, J. Aschmann, K. Bramstedt, M. Weber, C. von Savigny, A. Richter, A. Rozanov, F. Wittrock, F. Khosrawi, R. Bauer, and J. P. Burrows
Atmos. Chem. Phys., 14, 3247–3276, https://doi.org/10.5194/acp-14-3247-2014, https://doi.org/10.5194/acp-14-3247-2014, 2014
M. Langowski, M. Sinnhuber, A. C. Aikin, C. von Savigny, and J. P. Burrows
Atmos. Meas. Tech., 7, 29–48, https://doi.org/10.5194/amt-7-29-2014, https://doi.org/10.5194/amt-7-29-2014, 2014
N. Rahpoe, C. von Savigny, M. Weber, A.V. Rozanov, H. Bovensmann, and J. P. Burrows
Atmos. Meas. Tech., 6, 2825–2837, https://doi.org/10.5194/amt-6-2825-2013, https://doi.org/10.5194/amt-6-2825-2013, 2013
Related subject area
Subject: Dynamics | Research Activity: Remote Sensing | Altitude Range: Troposphere | Science Focus: Physics (physical properties and processes)
The Paris low-level jet during PANAME 2022 and its impact on the summertime urban heat island
An air quality and boundary layer dynamics analysis of the Los Angeles basin area during the Southwest Urban NOx and VOCs Experiment (SUNVEx)
Equatorial waves resolved by balloon-borne Global Navigation Satellite System radio occultation in the Strateole-2 campaign
Wind lidars reveal turbulence transport mechanism in the wake of a tree
On the role of aerosol radiative effect in the wet season onset timing over the Congo rainforest during boreal autumn
Study of the seasonal variation in Aeolus wind product performance over China using ERA5 and radiosonde data
Measurement report: characteristics of clear-day convective boundary layer and associated entrainment zone as observed by a ground-based polarization lidar over Wuhan (30.5° N, 114.4° E)
Technical note: First comparison of wind observations from ESA's satellite mission Aeolus and ground-based radar wind profiler network of China
Assessment of vertical air motion among reanalyses and qualitative comparison with very-high-frequency radar measurements over two tropical stations
Asian summer monsoon anticyclone: trends and variability
Very high stratospheric influence observed in the free troposphere over the northern Alps – just a local phenomenon?
Long-lived high-frequency gravity waves in the atmospheric boundary layer: observations and simulations
Variability of temperature and ozone in the upper troposphere and lower stratosphere from multi-satellite observations and reanalysis data
Mesoscale fine structure of a tropopause fold over mountains
Tropical convection regimes in climate models: evaluation with satellite observations
Wave modulation of the extratropical tropopause inversion layer
Planetary boundary layer height from CALIOP compared to radiosonde over China
Exploring atmospheric blocking with GPS radio occultation observations
Upper tropospheric water vapour variability at high latitudes – Part 1: Influence of the annular modes
Mixing layer height and its implications for air pollution over Beijing, China
Effect of tropical cyclones on the tropical tropopause parameters observed using COSMIC GPS RO data
New fire diurnal cycle characterizations to improve fire radiative energy assessments made from MODIS observations
Tropospheric ozone variability in the tropics from ENSO to MJO and shorter timescales
A comprehensive investigation on afternoon transition of the atmospheric boundary layer over a tropical rural site
Characterization of thermal structure and conditions for overshooting of tropical and extratropical cyclones with GPS radio occultation
Spatiotemporal variability of water vapor investigated using lidar and FTIR vertical soundings above the Zugspitze
Temperature profiling of the atmospheric boundary layer with rotational Raman lidar during the HD(CP)2 Observational Prototype Experiment
Determination and climatology of the planetary boundary layer height above the Swiss plateau by in situ and remote sensing measurements as well as by the COSMO-2 model
Comparison of the diurnal variations of warm-season precipitation for East Asia vs. North America downstream of the Tibetan Plateau vs. the Rocky Mountains
How stratospheric are deep stratospheric intrusions?
Impact of tropical land convection on the water vapour budget in the tropical tropopause layer
The thermodynamic state of the Arctic atmosphere observed by AIRS: comparisons during the record minimum sea ice extents of 2007 and 2012
High resolution VHF radar measurements of tropopause structure and variability at Davis, Antarctica (69° S, 78° E)
Measurements of the movement of the jet streams at mid-latitudes, in the Northern and Southern Hemispheres, 1979 to 2010
Continuous detection and characterization of the Sea Breeze in clear sky conditions using Meteosat Second Generation
Thermal structure of intense convective clouds derived from GPS radio occultations
Advances and limitations of atmospheric boundary layer observations with GPS occultation over southeast Pacific Ocean
Teleconnection between Australian winter temperature and Indian summer monsoon rainfall
First results from the GPS atmosphere sounding experiment TOR aboard the TerraSAR-X satellite
Updraft and downdraft characterization with Doppler lidar: cloud-free versus cumuli-topped mixed layer
Remote sensing of the tropical rain forest boundary layer using pulsed Doppler lidar
A new ENSO index derived from satellite measurements of column ozone
Turbulence associated with mountain waves over Northern Scandinavia – a case study using the ESRAD VHF radar and the WRF mesoscale model
Jonnathan Céspedes, Simone Kotthaus, Jana Preissler, Clément Toupoint, Ludovic Thobois, Marc-Antoine Drouin, Jean-Charles Dupont, Aurélien Faucheux, and Martial Haeffelin
Atmos. Chem. Phys., 24, 11477–11496, https://doi.org/10.5194/acp-24-11477-2024, https://doi.org/10.5194/acp-24-11477-2024, 2024
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The low-level jet (LLJ) is common in Paris during summer. The LLJ core height and speed significantly influence vertical mixing in the urban boundary layer, which affects air temperature variations between the urban canopy layer and surrounding rural areas, determining the urban heat island (UHI) intensity. This study highlights the importance of wind profile observations for understanding urban boundary layer dynamics and near-surface atmospheric conditions relevant to health.
Edward J. Strobach, Sunil Baidar, Brian J. Carroll, Steven S. Brown, Kristen Zuraski, Matthew Coggon, Chelsea E. Stockwell, Lu Xu, Yelena L. Pichugina, W. Alan Brewer, Carsten Warneke, Jeff Peischl, Jessica Gilman, Brandi McCarty, Maxwell Holloway, and Richard Marchbanks
Atmos. Chem. Phys., 24, 9277–9307, https://doi.org/10.5194/acp-24-9277-2024, https://doi.org/10.5194/acp-24-9277-2024, 2024
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Large-scale weather patterns are isolated from local patterns to study the impact that different weather scales have on air quality measurements. While impacts from large-scale meteorology were evaluated by separating ozone (O3) exceedance (>70 ppb) and non-exceedance (<70 ppb) days, we developed a technique that allows direct comparisons of small temporal variations between chemical and dynamics measurements under rapid dynamical transitions.
Bing Cao, Jennifer S. Haase, Michael J. Murphy, M. Joan Alexander, Martina Bramberger, and Albert Hertzog
Atmos. Chem. Phys., 22, 15379–15402, https://doi.org/10.5194/acp-22-15379-2022, https://doi.org/10.5194/acp-22-15379-2022, 2022
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Atmospheric waves that carry momentum from tropospheric weather systems into the equatorial stratosphere modify the winds there. The Strateole-2 2019 campaign launched long-duration stratospheric superpressure balloons to measure these equatorial waves. We deployed a GPS receiver on one of the balloons to measure atmospheric temperature profiles beneath the balloon. Temperature variations in the retrieved profiles show planetary-scale waves with a 20 d period and 3–4 d period waves.
Nikolas Angelou, Jakob Mann, and Ebba Dellwik
Atmos. Chem. Phys., 22, 2255–2268, https://doi.org/10.5194/acp-22-2255-2022, https://doi.org/10.5194/acp-22-2255-2022, 2022
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In this study we use state-of-the-art scanning wind lidars to investigate the wind field in the near-wake region of a mature, open-grown tree. Our measurements provide for the first time a picture of the mean and the turbulent spatial fluctuations in the flow in the wake of a tree in its natural environment. Our observations support the hypothesis that even simple models can realistically simulate the turbulent fluctuations in the wake and thus predict the effect of trees in flow models.
Sudip Chakraborty, Jonathon H. Jiang, Hui Su, and Rong Fu
Atmos. Chem. Phys., 21, 12855–12866, https://doi.org/10.5194/acp-21-12855-2021, https://doi.org/10.5194/acp-21-12855-2021, 2021
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Boreal autumn is the main wet season over the Congo basin. Thus, changes in its onset date have a significant impact on the rainforest. This study provides compelling evidence that the cooling effect of aerosols modifies the timing and strength of the southern African easterly jet that is central to the boreal autumn wet season over the Congo rainforest. A higher boreal summer aerosol concentration is positively correlated with the boreal autumn wet season onset timing.
Siying Chen, Rongzheng Cao, Yixuan Xie, Yinchao Zhang, Wangshu Tan, He Chen, Pan Guo, and Peitao Zhao
Atmos. Chem. Phys., 21, 11489–11504, https://doi.org/10.5194/acp-21-11489-2021, https://doi.org/10.5194/acp-21-11489-2021, 2021
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In this study, the seasonal variation in Aeolus wind product performance over China is analyzed by using L-band radiosonde detection data and ERA5 reanalysis data. The results show that the Aeolus wind product performance is affected by seasonal factors, which may be caused by seasonal changes in wind direction and cloud distribution.
Fuchao Liu, Fan Yi, Zhenping Yin, Yunpeng Zhang, Yun He, and Yang Yi
Atmos. Chem. Phys., 21, 2981–2998, https://doi.org/10.5194/acp-21-2981-2021, https://doi.org/10.5194/acp-21-2981-2021, 2021
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Using high-resolution lidar measurements, this process-based study reveals that the clear-day convective boundary layer evolves in four distinct stages differing in depth growth rate and depth fluctuation magnitudes. The accompanying entrainment zone thickness (EZT) shows a discrepancy in statistical mean and standard deviation for different seasons and developing stages. Common EZT characteristics also exist. These findings help us understand the atmospheric boundary layer evolution.
Jianping Guo, Boming Liu, Wei Gong, Lijuan Shi, Yong Zhang, Yingying Ma, Jian Zhang, Tianmeng Chen, Kaixu Bai, Ad Stoffelen, Gerrit de Leeuw, and Xiaofeng Xu
Atmos. Chem. Phys., 21, 2945–2958, https://doi.org/10.5194/acp-21-2945-2021, https://doi.org/10.5194/acp-21-2945-2021, 2021
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Vertical wind profiles are crucial to a wide range of atmospheric disciplines. Aeolus is the first satellite mission to directly observe wind profile information on a global scale. However, Aeolus wind products over China have thus far not been evaluated by in situ comparison. This work is expected to let the public and science community better know the Aeolus wind products and to encourage use of these valuable data in future research and applications.
Kizhathur Narasimhan Uma, Siddarth Shankar Das, Madineni Venkat Ratnam, and Kuniyil Viswanathan Suneeth
Atmos. Chem. Phys., 21, 2083–2103, https://doi.org/10.5194/acp-21-2083-2021, https://doi.org/10.5194/acp-21-2083-2021, 2021
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Reanalysis data of vertical wind (w) are widely used by the atmospheric community to determine various calculations of atmospheric circulations, diabatic heating, convection, etc. There are no studies that assess the available reanalysis data with respect to observations. The present study assesses for the first time all the reanalysis w by comparing it with 20 years of radar data from Gadanki and Kototabang and shows that downdrafts and peaks in the updrafts are not produced in the reanalyses.
Ghouse Basha, M. Venkat Ratnam, and Pangaluru Kishore
Atmos. Chem. Phys., 20, 6789–6801, https://doi.org/10.5194/acp-20-6789-2020, https://doi.org/10.5194/acp-20-6789-2020, 2020
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This study explores the variability of the Asian summer monsoon anticyclone (ASMA) spatial variability and trends using long-term observational and reanalysis data sets. The decadal variability of the anticyclone is very large at the edges compared with the core region. We propose that the transport process over the Tibetan Plateau and the Indian region is significant in active monsoon, strong monsoon and strong La Niña years. Thus, different phases of the monsoon are important in UTLS analyses.
Thomas Trickl, Hannes Vogelmann, Ludwig Ries, and Michael Sprenger
Atmos. Chem. Phys., 20, 243–266, https://doi.org/10.5194/acp-20-243-2020, https://doi.org/10.5194/acp-20-243-2020, 2020
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Ozone transfer from the stratosphere to the troposphere seems to to have grown over the past decade, parallel to global warming. Lidar measurements, carried out in Garmisch-Partenkirchen, Germany, between 2007 and 2016 show a considerable stratospheric influence in the free troposphere over these sites, with observations of stratospheric layers in the troposphere on 84 % of the measurement days. This high fraction is almost reached also in North America, but frequently not throughout the year.
Mingjiao Jia, Jinlong Yuan, Chong Wang, Haiyun Xia, Yunbin Wu, Lijie Zhao, Tianwen Wei, Jianfei Wu, Lu Wang, Sheng-Yang Gu, Liqun Liu, Dachun Lu, Rulong Chen, Xianghui Xue, and Xiankang Dou
Atmos. Chem. Phys., 19, 15431–15446, https://doi.org/10.5194/acp-19-15431-2019, https://doi.org/10.5194/acp-19-15431-2019, 2019
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Gravitational waves (GWs) with periods ranging from 10 to 30 min over 10 h and 20 wave cycles are detected within a 2 km height in the atmospheric boundary layer (ABL) by a coherent Doppler wind lidar. Observations and computational fluid dynamics (CFD) simulations lead to a conclusion that the GWs are excited by the wind shear of a low-level jet under the condition of light horizontal wind. The GWs are trapped in the ABL due to a combination of thermal and Doppler ducts.
Ming Shangguan, Wuke Wang, and Shuanggen Jin
Atmos. Chem. Phys., 19, 6659–6679, https://doi.org/10.5194/acp-19-6659-2019, https://doi.org/10.5194/acp-19-6659-2019, 2019
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A significant warming in the troposphere and cooling in the stratosphere are found in satellite measurements (2002–2017). The newest ERA5 data are first used for analyzing temperature and ozone trends in the UTLS and show the best quality compared to other reanalyses. According to model simulations, the temperature increase in the troposphere and ozone decrease in the NH stratosphere are mainly connected to a surface warming of the ocean and subsequent changes in atmospheric circulation.
Wolfgang Woiwode, Andreas Dörnbrack, Martina Bramberger, Felix Friedl-Vallon, Florian Haenel, Michael Höpfner, Sören Johansson, Erik Kretschmer, Isabell Krisch, Thomas Latzko, Hermann Oelhaf, Johannes Orphal, Peter Preusse, Björn-Martin Sinnhuber, and Jörn Ungermann
Atmos. Chem. Phys., 18, 15643–15667, https://doi.org/10.5194/acp-18-15643-2018, https://doi.org/10.5194/acp-18-15643-2018, 2018
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GLORIA observations during two crossings of the polar front jet stream resolve the fine mesoscale structure of a tropopause fold in high detail. Tracer–tracer correlations of H2O and O3 are presented as a function of potential temperature and reveal an active mixing region. Our study confirms conceptual models of tropopause folds, validates the high quality of ECMWF IFS forecasts, and suggests that mountain waves are capable of modulating exchange processes in the vicinity of tropopause folds.
Andrea K. Steiner, Bettina C. Lackner, and Mark A. Ringer
Atmos. Chem. Phys., 18, 4657–4672, https://doi.org/10.5194/acp-18-4657-2018, https://doi.org/10.5194/acp-18-4657-2018, 2018
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We evaluate the representation of tropical convection regimes in atmospheric climate models with satellite-based observations from GPS radio occultation. We find that models have large temperature biases in the tropopause region. In moist convection regions, models underestimate moisture up to 40 % over oceans whereas in dry regions they overestimate it by 100 %. Our findings show that RO observations are a valuable data source for the evaluation and development of next generation climate models.
Robin Pilch Kedzierski, Katja Matthes, and Karl Bumke
Atmos. Chem. Phys., 17, 4093–4114, https://doi.org/10.5194/acp-17-4093-2017, https://doi.org/10.5194/acp-17-4093-2017, 2017
Wanchun Zhang, Jianping Guo, Yucong Miao, Huan Liu, Yong Zhang, Zhengqiang Li, and Panmao Zhai
Atmos. Chem. Phys., 16, 9951–9963, https://doi.org/10.5194/acp-16-9951-2016, https://doi.org/10.5194/acp-16-9951-2016, 2016
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The PBL height retrieval from CALIOP aboard CALIPSO can significantly complement the traditional ground-based methods, which is only for one site. Our study, to our current knowledge, is the first intercomparison study of PBLH on a large scale using long-term radiosonde observations in China. Three matchup schemes were proposed based on the position of radiosondes relative to CALIPSO ground tracks in China. Results indicate that CALIOP is promising for reliable PBLH retrievals.
Lukas Brunner, Andrea K. Steiner, Barbara Scherllin-Pirscher, and Martin W. Jury
Atmos. Chem. Phys., 16, 4593–4604, https://doi.org/10.5194/acp-16-4593-2016, https://doi.org/10.5194/acp-16-4593-2016, 2016
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Atmospheric blocking refers to persistent high-pressure systems which block the climatological flow at midlatitudes. We explore blocking with observations from GPS radio occultation (RO), a satellite-based remote-sensing system. Using two example cases, we find that RO data robustly capture blocking, highlighting the potential of RO observations to complement models and reanalysis as a basis for blocking research.
Christopher E. Sioris, Jason Zou, David A. Plummer, Chris D. Boone, C. Thomas McElroy, Patrick E. Sheese, Omid Moeini, and Peter F. Bernath
Atmos. Chem. Phys., 16, 3265–3278, https://doi.org/10.5194/acp-16-3265-2016, https://doi.org/10.5194/acp-16-3265-2016, 2016
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The AM (annular mode) is the most important internal mode of climatic variability at high latitudes. Upper tropospheric water vapour (UTWV) at high latitudes increases by up to ~ 50 % during the negative phase of the AMs. The response of water vapour to the AMs vanishes above the tropopause. The ultimate goal of the study was to improve UTWV trend uncertainties by explaining shorter-term variability, and this was achieved by accounting for the AM-related response in a multiple linear regression.
Guiqian Tang, Jinqiang Zhang, Xiaowan Zhu, Tao Song, Christoph Münkel, Bo Hu, Klaus Schäfer, Zirui Liu, Junke Zhang, Lili Wang, Jinyuan Xin, Peter Suppan, and Yuesi Wang
Atmos. Chem. Phys., 16, 2459–2475, https://doi.org/10.5194/acp-16-2459-2016, https://doi.org/10.5194/acp-16-2459-2016, 2016
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This is the first paper to validate and characterize mixing layer height and discuss its relationship with air pollution, using a ceilometer in Beijing. The novelty, originality, and importance of this paper are as follows: (1) the applicable conditions of the ceilometer; (2) the variations of mixing layer height; (3) thermal/dynamic structure inside mixing layers with different degrees of pollution; and (4) critical meteorological conditions for the formation of heavy air pollution.
S. Ravindra Babu, M. Venkat Ratnam, G. Basha, B. V. Krishnamurthy, and B. Venkateswararao
Atmos. Chem. Phys., 15, 10239–10249, https://doi.org/10.5194/acp-15-10239-2015, https://doi.org/10.5194/acp-15-10239-2015, 2015
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The effect of tropical cyclones (TCs) that occurred over the north Indian Ocean in the last decade on the tropical tropopause parameters has been quantified for the first time. The vertical structure of temperature and tropopause parameters within the 5º radius away from the cyclone centre during TC period is also presented. The water vapour variability in the vicinity of TC is investigated.
It is demonstrated that the TCs can significantly affect the tropical tropopause and thus STE processes.
N. Andela, J. W. Kaiser, G. R. van der Werf, and M. J. Wooster
Atmos. Chem. Phys., 15, 8831–8846, https://doi.org/10.5194/acp-15-8831-2015, https://doi.org/10.5194/acp-15-8831-2015, 2015
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The polar orbiting MODIS instruments provide four daily observations of the fire diurnal cycle, resulting in erroneous fire radiative energy (FRE) estimates. Using geostationary SEVIRI data, we explore the fire diurnal cycle and its drivers for Africa to develop a new method to estimate global FRE in near real-time using MODIS. The fire diurnal cycle varied with climate and vegetation type, and including information on the fire diurnal cycle in the model significantly improved the FRE estimates.
J. R. Ziemke, A. R. Douglass, L. D. Oman, S. E. Strahan, and B. N. Duncan
Atmos. Chem. Phys., 15, 8037–8049, https://doi.org/10.5194/acp-15-8037-2015, https://doi.org/10.5194/acp-15-8037-2015, 2015
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Aura OMI and MLS measurements are combined to produce daily maps of tropospheric ozone beginning October 2004. We show that El Niño Southern Oscillation (ENSO) related inter-annual change in tropospheric ozone in the tropics is small compared to combined intra-seasonal/Madden-Julian Oscillation (MJO) and shorter timescale variability. Outgoing Longwave Radiation indicates that deep convection is the primary driver of the observed ozone variability on all timescales.
A. Sandeep, T. N. Rao, and S. V. B. Rao
Atmos. Chem. Phys., 15, 7605–7617, https://doi.org/10.5194/acp-15-7605-2015, https://doi.org/10.5194/acp-15-7605-2015, 2015
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The afternoon-evening transition (AET) in the atmospheric boundary layer has been studied in an integrated approach using 3 years of tower, sodar and wind profiler measurements. Such a long-term data set has been used for the first time to understand the behavior of AET. It allowed us to study the seasonal variation. In contrast to the common belief that the transition evolves from bottom to top, the present study clearly showed that the start time of transition follows top-to-bottom evolution.
R. Biondi, A. K. Steiner, G. Kirchengast, and T. Rieckh
Atmos. Chem. Phys., 15, 5181–5193, https://doi.org/10.5194/acp-15-5181-2015, https://doi.org/10.5194/acp-15-5181-2015, 2015
H. Vogelmann, R. Sussmann, T. Trickl, and A. Reichert
Atmos. Chem. Phys., 15, 3135–3148, https://doi.org/10.5194/acp-15-3135-2015, https://doi.org/10.5194/acp-15-3135-2015, 2015
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We quantitatively analyzed the spatiotemporal variability (minutes to hours, 500m to 10km) of water vapor (IWV and profiles) in the free troposphere recorded at the Zugspitze (Germany) with lidar and solar FTIR. We found that long-range transport of heterogeneous air masses may cause relative short-term variations of the water-vapor density which exceed the impact of local convection by 1 order of magnitude. Our results could be useful for issues of model parametrization and co-location.
E. Hammann, A. Behrendt, F. Le Mounier, and V. Wulfmeyer
Atmos. Chem. Phys., 15, 2867–2881, https://doi.org/10.5194/acp-15-2867-2015, https://doi.org/10.5194/acp-15-2867-2015, 2015
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Measurements and upgrades of the rotational Raman lidar of the University of Hohenheim during the HD(CP)2 Observational Prototype Experiment are presented in this paper. This includes 25h long time series of temperature gradients and water vapor mixing ratio. Through simulation, optimum wavelengths for high- and low-background cases were identified and tested successfully. Low-elevation measurements were performed to measure temperature gradients at altitudes around 100m above ground level.
M. Collaud Coen, C. Praz, A. Haefele, D. Ruffieux, P. Kaufmann, and B. Calpini
Atmos. Chem. Phys., 14, 13205–13221, https://doi.org/10.5194/acp-14-13205-2014, https://doi.org/10.5194/acp-14-13205-2014, 2014
Short summary
Short summary
An operational planetary boundary layer height detection method with several remote sensing instruments (wind profiler, Raman lidar, microwave radiometer) and algorithms (Parcel and bulk Richardson number methods, surface-based temperature inversion, aerosol and humidity gradient analysis) was validated against radio sounding. A comparison with the numerical weather prediction model COSMO-2 and the seasonal cycles of the day- and nighttime PBL for two stations on the Swiss plateau are presented.
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Short summary
We examine a possible statistical linkage between atmospheric variability in the tropical troposphere on the intraseasonal timescale, which is known as Madden–Julian oscillation, and known variability of the solar radiation with a period of 27 days. This helps to understand tropospheric variability in more detail, which is generally of interest, e.g., for weather forecasting. We find indications for such a linkage; however, more research has to be conducted for an unambiguous attribution.
We examine a possible statistical linkage between atmospheric variability in the tropical...
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