Articles | Volume 21, issue 20
https://doi.org/10.5194/acp-21-15619-2021
© Author(s) 2021. 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-21-15619-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
19 Oct 2021
Research article | Highlight paper |
| 19 Oct 2021
| 19 Oct 2021
Self-consistent global transport of metallic ions with WACCM-X
Jianfei Wu
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
CAS Center for Excellence in Comparative Planetology, Hefei, China
Mengcheng National Geophysical Observatory, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
Wuhu Feng
School of Chemistry, University of Leeds, Leeds, UK
National Center for Atmospheric Science, University of Leeds, Leeds, UK
Han-Li Liu
National Center for Atmospheric Research, Boulder, Colorado, USA
CAS Key Laboratory of Geospace Environment, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
CAS Center for Excellence in Comparative Planetology, Hefei, China
Mengcheng National Geophysical Observatory, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, China
Hefei National Laboratory for the Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, China
Frontiers Science Center for Planetary Exploration and Emerging Technologies, University of Science and
Technology of China, Hefei, China
Daniel Robert Marsh
National Center for Atmospheric Research, Boulder, Colorado, USA
Faculty of Engineering and Physical Sciences, University of Leeds, Leeds, UK
John Maurice Campbell Plane
CORRESPONDING AUTHOR
School of Chemistry, University of Leeds, Leeds, UK
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A 3-D chemical transport model, TOMCAT, is used to simulate global atmospheric carbonyl sulfide (OCS) distribution. Modelled OCS compares well with satellite observations of OCS from limb-sounding satellite observations. Model simulations also compare adequately with surface and atmospheric observations and suitably capture the seasonality of OCS and background concentrations.
Robert Wagner, Alexander D. James, Victoria L. Frankland, Ottmar Möhler, Benjamin J. Murray, John M. C. Plane, Harald Saathoff, Ralf Weigel, and Martin Schnaiter
Atmos. Chem. Phys., 23, 6789–6811, https://doi.org/10.5194/acp-23-6789-2023, https://doi.org/10.5194/acp-23-6789-2023, 2023
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Polar stratospheric clouds (PSCs) play an important role in the depletion of stratospheric ozone. They can consist of different chemical species, including crystalline nitric acid hydrates. We found that mineral dust or meteoric ablation material can efficiently catalyse the formation of a specific phase of nitric acid dihydrate crystals. We determined predominant particle shapes and infrared optical properties of these crystals, which are important inputs for remote sensing detection of PSCs.
Alexander D. James, Finn Pace, Sebastien N. F. Sikora, Graham W. Mann, John M. C. Plane, and Benjamin J. Murray
Atmos. Chem. Phys., 23, 2215–2233, https://doi.org/10.5194/acp-23-2215-2023, https://doi.org/10.5194/acp-23-2215-2023, 2023
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Here, we examine whether several materials of meteoric origin can nucleate crystallisation in stratospheric cloud droplets which would affect ozone depletion. We find that material which could fragment on atmospheric entry without melting is unlikely to be present in high enough concentration in the stratosphere to contribute to observed crystalline clouds. Material which ablates completely then forms a new solid known as meteoric smoke can provide enough nucleation to explain observed clouds.
Cornelius Csar Jude H. Salinas, Dong L. Wu, Jae N. Lee, Loren C. Chang, Liying Qian, and Hanli Liu
Atmos. Chem. Phys., 23, 1705–1730, https://doi.org/10.5194/acp-23-1705-2023, https://doi.org/10.5194/acp-23-1705-2023, 2023
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Upper mesospheric carbon monoxide's (CO) photochemical lifetime is longer than dynamical timescales. This work uses satellite observations and model simulations to establish that the migrating diurnal tide and its seasonal and interannual variabilities drive CO primarily through vertical advection. Vertical advection is a transport process that is currently difficult to observe. This work thus shows that we can use CO as a tracer for vertical advection across seasonal and interannual timescales.
Wen Yi, Jie Zeng, Xianghui Xue, Iain Reid, Wei Zhong, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-254, https://doi.org/10.5194/amt-2022-254, 2022
Revised manuscript not accepted
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In recent years, the concept of multistatic meteor radar systems has attracted the attention of the atmospheric radar community, focusing on the MLT region. In this study, we apply a multistatic meteor radar system consisting of a monostatic meteor radar in Mengcheng (33.36° N, 116.49° E) and a remote receiver in Changfeng (31.98° N, 117.22° E) to estimate the two-dimensional horizontal wind field, and the horizontal divergence and relative vorticity of the wind field.
Qinzeng Li, Jiyao Xu, Hanli Liu, Xiao Liu, and Wei Yuan
Atmos. Chem. Phys., 22, 12077–12091, https://doi.org/10.5194/acp-22-12077-2022, https://doi.org/10.5194/acp-22-12077-2022, 2022
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We use ground-based airglow network observations, reanalysis data, and satellite observations to explore the propagation process of concentric gravity waves (CGWs) excited by a typhoon between the troposphere, stratosphere, mesosphere, and thermosphere. We find that CGWs in the mesosphere are generated directly by the typhoon but the CGW observed in the thermosphere may be excited by CGW dissipation in the mesosphere, rather than directly excited by a typhoon and propagated to the thermosphere.
Bingkun Yu, Xianghui Xue, Christopher J. Scott, Mingjiao Jia, Wuhu Feng, John M. C. Plane, Daniel R. Marsh, Jonas Hedin, Jörg Gumbel, and Xiankang Dou
Atmos. Chem. Phys., 22, 11485–11504, https://doi.org/10.5194/acp-22-11485-2022, https://doi.org/10.5194/acp-22-11485-2022, 2022
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We present a study on the climatology of the metal sodium layer in the upper atmosphere from the ground-based measurements obtained from a lidar network, the Odin satellite measurements, and a global model of meteoric sodium in the atmosphere. Comprehensively, comparisons show good agreement and some discrepancies between ground-based observations, satellite measurements, and global model simulations.
Yajuan Li, Sandip S. Dhomse, Martyn P. Chipperfield, Wuhu Feng, Andreas Chrysanthou, Yuan Xia, and Dong Guo
Atmos. Chem. Phys., 22, 10635–10656, https://doi.org/10.5194/acp-22-10635-2022, https://doi.org/10.5194/acp-22-10635-2022, 2022
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Chemical transport models forced with (re)analysis meteorological fields are ideally suited for interpreting the influence of important physical processes on the ozone variability. We use TOMCAT forced by ECMWF ERA-Interim and ERA5 reanalysis data sets to investigate the effects of reanalysis forcing fields on ozone changes. Our results show that models forced by ERA5 reanalyses may not yet be capable of reproducing observed changes in stratospheric ozone, particularly in the lower stratosphere.
Matilda A. Pimlott, Richard J. Pope, Brian J. Kerridge, Barry G. Latter, Diane S. Knappett, Dwayne E. Heard, Lucy J. Ventress, Richard Siddans, Wuhu Feng, and Martyn P. Chipperfield
Atmos. Chem. Phys., 22, 10467–10488, https://doi.org/10.5194/acp-22-10467-2022, https://doi.org/10.5194/acp-22-10467-2022, 2022
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We present a new method to derive global information of the hydroxyl radical (OH), an important atmospheric oxidant. OH controls the lifetime of trace gases important to air quality and climate. We use satellite observations of ozone, carbon monoxide, methane and water vapour in a simple expression to derive OH around 3–4 km altitude. The derived OH compares well to model and aircraft OH data. We then apply the method to 10 years of satellite data to study the inter-annual variability of OH.
Davide Zanchettin, Claudia Timmreck, Myriam Khodri, Anja Schmidt, Matthew Toohey, Manabu Abe, Slimane Bekki, Jason Cole, Shih-Wei Fang, Wuhu Feng, Gabriele Hegerl, Ben Johnson, Nicolas Lebas, Allegra N. LeGrande, Graham W. Mann, Lauren Marshall, Landon Rieger, Alan Robock, Sara Rubinetti, Kostas Tsigaridis, and Helen Weierbach
Geosci. Model Dev., 15, 2265–2292, https://doi.org/10.5194/gmd-15-2265-2022, https://doi.org/10.5194/gmd-15-2265-2022, 2022
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This paper provides metadata and first analyses of the volc-pinatubo-full experiment of CMIP6-VolMIP. Results from six Earth system models reveal significant differences in radiative flux anomalies that trace back to different implementations of volcanic forcing. Surface responses are in contrast overall consistent across models, reflecting the large spread due to internal variability. A second phase of VolMIP shall consider both aspects toward improved protocol for volc-pinatubo-full.
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
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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.
Ioannis A. Daglis, Loren C. Chang, Sergio Dasso, Nat Gopalswamy, Olga V. Khabarova, Emilia Kilpua, Ramon Lopez, Daniel Marsh, Katja Matthes, Dibyendu Nandy, Annika Seppälä, Kazuo Shiokawa, Rémi Thiéblemont, and Qiugang Zong
Ann. Geophys., 39, 1013–1035, https://doi.org/10.5194/angeo-39-1013-2021, https://doi.org/10.5194/angeo-39-1013-2021, 2021
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We present a detailed account of the science programme PRESTO (PREdictability of the variable Solar–Terrestrial cOupling), covering the period 2020 to 2024. PRESTO was defined by a dedicated committee established by SCOSTEP (Scientific Committee on Solar-Terrestrial Physics). We review the current state of the art and discuss future studies required for the most effective development of solar–terrestrial physics.
Sandip S. Dhomse, Carlo Arosio, Wuhu Feng, Alexei Rozanov, Mark Weber, and Martyn P. Chipperfield
Earth Syst. Sci. Data, 13, 5711–5729, https://doi.org/10.5194/essd-13-5711-2021, https://doi.org/10.5194/essd-13-5711-2021, 2021
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High-quality long-term ozone profile data sets are key to estimating short- and long-term ozone variability. Almost all the satellite (and chemical model) data sets show some kind of bias with respect to each other. This is because of differences in measurement methodologies as well as simplified processes in the models. We use satellite data sets and chemical model output to generate 42 years of ozone profile data sets using a random-forest machine-learning algorithm that is named ML-TOMCAT.
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
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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.
Gunter Stober, Ales Kuchar, Dimitry Pokhotelov, Huixin Liu, Han-Li Liu, Hauke Schmidt, Christoph Jacobi, Kathrin Baumgarten, Peter Brown, Diego Janches, Damian Murphy, Alexander Kozlovsky, Mark Lester, Evgenia Belova, Johan Kero, and Nicholas Mitchell
Atmos. Chem. Phys., 21, 13855–13902, https://doi.org/10.5194/acp-21-13855-2021, https://doi.org/10.5194/acp-21-13855-2021, 2021
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Little is known about the climate change of wind systems in the mesosphere and lower thermosphere at the edge of space at altitudes from 70–110 km. Meteor radars represent a well-accepted remote sensing technique to measure winds at these altitudes. Here we present a state-of-the-art climatological interhemispheric comparison using continuous and long-lasting observations from worldwide distributed meteor radars from the Arctic to the Antarctic and sophisticated general circulation models.
Ville Maliniemi, Hilde Nesse Tyssøy, Christine Smith-Johnsen, Pavle Arsenovic, and Daniel R. Marsh
Atmos. Chem. Phys., 21, 11041–11052, https://doi.org/10.5194/acp-21-11041-2021, https://doi.org/10.5194/acp-21-11041-2021, 2021
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We simulate ozone variability over the 21st century with different greenhouse gas scenarios. Our results highlight a novel mechanism of additional reactive nitrogen species descending to the Antarctic stratosphere from the thermosphere/upper mesosphere due to the accelerated residual circulation under climate change. This excess descending NOx can potentially prevent a super recovery of ozone in the Antarctic upper stratosphere.
Michael Kiefer, Thomas von Clarmann, Bernd Funke, Maya García-Comas, Norbert Glatthor, Udo Grabowski, Sylvia Kellmann, Anne Kleinert, Alexandra Laeng, Andrea Linden, Manuel López-Puertas, Daniel R. Marsh, and Gabriele P. Stiller
Atmos. Meas. Tech., 14, 4111–4138, https://doi.org/10.5194/amt-14-4111-2021, https://doi.org/10.5194/amt-14-4111-2021, 2021
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An improved dataset of vertical temperature profiles of the Earth's atmosphere in the altitude range 5–70 km is presented. These profiles are derived from measurements of the MIPAS instrument onboard ESA's Envisat satellite. The overall improvements are based on upgrades in the input data and several improvements in the data processing approach. Both of these are discussed, and an extensive error discussion is included. Enhancements of the new dataset are demonstrated by means of examples.
Wei Zhong, Xianghui Xue, Wen Yi, Iain M. Reid, Tingdi Chen, and Xiankang Dou
Atmos. Meas. Tech., 14, 3973–3988, https://doi.org/10.5194/amt-14-3973-2021, https://doi.org/10.5194/amt-14-3973-2021, 2021
Bingkun Yu, Xianghui Xue, Christopher J. Scott, Jianfei Wu, Xinan Yue, Wuhu Feng, Yutian Chi, Daniel R. Marsh, Hanli Liu, Xiankang Dou, and John M. C. Plane
Atmos. Chem. Phys., 21, 4219–4230, https://doi.org/10.5194/acp-21-4219-2021, https://doi.org/10.5194/acp-21-4219-2021, 2021
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A long-standing mystery of metal ions within Es layers in the Earth's upper atmosphere is the marked seasonal dependence, with a summer maximum and a winter minimum. We report a large-scale winter-to-summer transport of metal ions from 6-year multi-satellite observations and worldwide ground-based stations. A global atmospheric circulation is responsible for the phenomenon. Our results emphasise the effect of this atmospheric circulation on the transport of composition in the upper atmosphere.
Minna Palmroth, Maxime Grandin, Theodoros Sarris, Eelco Doornbos, Stelios Tourgaidis, Anita Aikio, Stephan Buchert, Mark A. Clilverd, Iannis Dandouras, Roderick Heelis, Alex Hoffmann, Nickolay Ivchenko, Guram Kervalishvili, David J. Knudsen, Anna Kotova, Han-Li Liu, David M. Malaspina, Günther March, Aurélie Marchaudon, Octav Marghitu, Tomoko Matsuo, Wojciech J. Miloch, Therese Moretto-Jørgensen, Dimitris Mpaloukidis, Nils Olsen, Konstantinos Papadakis, Robert Pfaff, Panagiotis Pirnaris, Christian Siemes, Claudia Stolle, Jonas Suni, Jose van den IJssel, Pekka T. Verronen, Pieter Visser, and Masatoshi Yamauchi
Ann. Geophys., 39, 189–237, https://doi.org/10.5194/angeo-39-189-2021, https://doi.org/10.5194/angeo-39-189-2021, 2021
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This is a review paper that summarises the current understanding of the lower thermosphere–ionosphere (LTI) in terms of measurements and modelling. The LTI is the transition region between space and the atmosphere and as such of tremendous importance to both the domains of space and atmosphere. The paper also serves as the background for European Space Agency Earth Explorer 10 candidate mission Daedalus.
Tong Dang, Binzheng Zhang, Jiuhou Lei, Wenbin Wang, Alan Burns, Han-li Liu, Kevin Pham, and Kareem A. Sorathia
Geosci. Model Dev., 14, 859–873, https://doi.org/10.5194/gmd-14-859-2021, https://doi.org/10.5194/gmd-14-859-2021, 2021
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This paper describes a numerical treatment (ring average) to relax the time step in finite-difference schemes when using spherical and cylindrical coordinates with axis singularities. The ring average is used to develop a high-resolution thermosphere–ionosphere coupled community model. The technique is a significant improvement in space weather modeling capability, and it can also be adapted to more general finite-difference solvers for hyperbolic equations in spherical and polar geometries.
Jianyuan Wang, Wen Yi, Jianfei Wu, Tingdi Chen, Xianghui Xue, Robert A. Vincent, Iain M. Reid, Paulo P. Batista, Ricardo A. Buriti, Toshitaka Tsuda, and Xiankang Dou
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2021-33, https://doi.org/10.5194/acp-2021-33, 2021
Revised manuscript not accepted
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In this study, we report the climatology of migrating and non-migrating tides in mesopause winds estimated using multiyear observations from three meteor radars in the southern equatorial region. The results reveal that the climatological patterns of tidal amplitudes by meteor radars is similar to the Climatological Tidal Model of the Thermosphere (CTMT) results and the differences are mainly due to the effect of the stratospheric sudden warming (SSW) event.
Arseniy Karagodin-Doyennel, Eugene Rozanov, Ales Kuchar, William Ball, Pavle Arsenovic, Ellis Remsberg, Patrick Jöckel, Markus Kunze, David A. Plummer, Andrea Stenke, Daniel Marsh, Doug Kinnison, and Thomas Peter
Atmos. Chem. Phys., 21, 201–216, https://doi.org/10.5194/acp-21-201-2021, https://doi.org/10.5194/acp-21-201-2021, 2021
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The solar signal in the mesospheric H2O and CO was extracted from the CCMI-1 model simulations and satellite observations using multiple linear regression (MLR) analysis. MLR analysis shows a pronounced and statistically robust solar signal in both H2O and CO. The model results show a general agreement with observations reproducing a negative/positive solar signal in H2O/CO. The pattern of the solar signal varies among the considered models, reflecting some differences in the model setup.
Xiao Liu, Jiyao Xu, Jia Yue, and Hanli Liu
Atmos. Chem. Phys., 20, 14437–14456, https://doi.org/10.5194/acp-20-14437-2020, https://doi.org/10.5194/acp-20-14437-2020, 2020
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Large wind shears in the mesosphere and lower thermosphere are recognized as a common phenomenon. Simulation and ground-based observations show that the main contributor of large wind shears is gravity waves. We present a method of deriving wind shears induced by gravity waves according to the linear theory and using the global temperature observations by SABER (Sounding of the Atmosphere using Broadband Emission Radiometry). Our results agree well with observations and model simulations.
Benjamin Birner, Martyn P. Chipperfield, Eric J. Morgan, Britton B. Stephens, Marianna Linz, Wuhu Feng, Chris Wilson, Jonathan D. Bent, Steven C. Wofsy, Jeffrey Severinghaus, and Ralph F. Keeling
Atmos. Chem. Phys., 20, 12391–12408, https://doi.org/10.5194/acp-20-12391-2020, https://doi.org/10.5194/acp-20-12391-2020, 2020
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With new high-precision observations from nine aircraft campaigns and 3-D chemical transport modeling, we show that the argon-to-nitrogen ratio (Ar / N2) in the lowermost stratosphere provides a useful constraint on the “age of air” (the time elapsed since entry of an air parcel into the stratosphere). Therefore, Ar / N2 in combination with traditional age-of-air indicators, such as CO2 and N2O, could provide new insights into atmospheric mixing and transport.
Thomas R. Lewis, Juan Carlos Gómez Martín, Mark A. Blitz, Carlos A. Cuevas, John M. C. Plane, and Alfonso Saiz-Lopez
Atmos. Chem. Phys., 20, 10865–10887, https://doi.org/10.5194/acp-20-10865-2020, https://doi.org/10.5194/acp-20-10865-2020, 2020
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Iodine-bearing gasses emitted from the sea surface are chemically processed in the atmosphere, leading to iodine accumulation in aerosol and transport to continental ecosystems. Such processing involves light-induced break-up of large, particle-forming iodine oxides into smaller, ozone-depleting molecules. We combine experiments and theory to report the photolysis efficiency of iodine oxides required to assess the impact of iodine on ozone depletion and particle formation.
Niilo Kalakoski, Pekka T. Verronen, Annika Seppälä, Monika E. Szeląg, Antti Kero, and Daniel R. Marsh
Atmos. Chem. Phys., 20, 8923–8938, https://doi.org/10.5194/acp-20-8923-2020, https://doi.org/10.5194/acp-20-8923-2020, 2020
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Effects of solar proton events (SPEs) on middle atmosphere chemistry were studied using the WACCM-D chemistry–climate model, including an improved representation of lower ionosphere ion chemistry. This study includes 66 events in the years 1989–2012 and uses a statistical approach to determine the impact of the improved chemistry scheme. The differences shown highlight the importance of ion chemistry in models used to study energetic particle precipitation.
Yajuan Li, Martyn P. Chipperfield, Wuhu Feng, Sandip S. Dhomse, Richard J. Pope, Faquan Li, and Dong Guo
Atmos. Chem. Phys., 20, 8627–8639, https://doi.org/10.5194/acp-20-8627-2020, https://doi.org/10.5194/acp-20-8627-2020, 2020
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The Tibetan Plateau (TP) exerts important thermal and dynamical effects on atmospheric circulation, climate change as well as the ozone distribution. In this study, we use updated observations and model simulations to investigate the ozone trends and variations over the TP. Wintertime TP ozone variations are largely controlled by tropical to high-latitude transport processes, whereas summertime concentrations are a combined effect of photochemical decay and tropical processes.
Pekka T. Verronen, Daniel R. Marsh, Monika E. Szeląg, and Niilo Kalakoski
Ann. Geophys., 38, 833–844, https://doi.org/10.5194/angeo-38-833-2020, https://doi.org/10.5194/angeo-38-833-2020, 2020
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This paper is the first to study how the representation of the magnetic-local-time (MLT) dependency of electron precipitation impacts middle-atmospheric-ozone response on monthly timescales. We use a state-of-the-art chemistry–climate model with detailed lower-ionospheric chemistry for an advanced representation of atmospheric impacts of electron forcing. We find that the use of daily zonal-mean electron forcing will provide an accurate ozone response in long-term climate simulations.
Clara Orbe, David A. Plummer, Darryn W. Waugh, Huang Yang, Patrick Jöckel, Douglas E. Kinnison, Beatrice Josse, Virginie Marecal, Makoto Deushi, Nathan Luke Abraham, Alexander T. Archibald, Martyn P. Chipperfield, Sandip Dhomse, Wuhu Feng, and Slimane Bekki
Atmos. Chem. Phys., 20, 3809–3840, https://doi.org/10.5194/acp-20-3809-2020, https://doi.org/10.5194/acp-20-3809-2020, 2020
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Atmospheric composition is strongly influenced by global-scale winds that are not always properly simulated in computer models. A common approach to correct for this bias is to relax or
nudgeto the observed winds. Here we systematically evaluate how well this technique performs across a large suite of chemistry–climate models in terms of its ability to reproduce key aspects of both the tropospheric and stratospheric circulations.
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.
Ingo Wohltmann, Ralph Lehmann, Georg A. Gottwald, Karsten Peters, Alain Protat, Valentin Louf, Christopher Williams, Wuhu Feng, and Markus Rex
Geosci. Model Dev., 12, 4387–4407, https://doi.org/10.5194/gmd-12-4387-2019, https://doi.org/10.5194/gmd-12-4387-2019, 2019
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We present a trajectory-based model for simulating the transport of air parcels by convection. Our model extends the approach of existing models by explicitly simulating vertical updraft velocities inside the clouds and the time that an air parcel spends inside the convective event.
Tasha Aylett, James S. A. Brooke, Alexander D. James, Mario Nachbar, Denis Duft, Thomas Leisner, and John M. C. Plane
Atmos. Chem. Phys., 19, 12767–12777, https://doi.org/10.5194/acp-19-12767-2019, https://doi.org/10.5194/acp-19-12767-2019, 2019
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Interplanetary dust particles entering the Earth's atmosphere often melt and evaporate, injecting metals such as iron and magnesium into the atmosphere between 80 and 105 km. These metals become oxidized and then coagulate into small particles a few nanometres is size, known as meteoric smoke. In this study, iron oxide smoke particles were created in the laboratory, and their composition and optical properties were determined in order to understand satellite measurements.
Matthew J. Rowlinson, Alexandru Rap, Stephen R. Arnold, Richard J. Pope, Martyn P. Chipperfield, Joe McNorton, Piers Forster, Hamish Gordon, Kirsty J. Pringle, Wuhu Feng, Brian J. Kerridge, Barry L. Latter, and Richard Siddans
Atmos. Chem. Phys., 19, 8669–8686, https://doi.org/10.5194/acp-19-8669-2019, https://doi.org/10.5194/acp-19-8669-2019, 2019
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Wildfires and meteorology have a substantial effect on atmospheric concentrations of greenhouse gases such as methane and ozone. During the 1997 El Niño event, unusually large fire emissions indirectly increased global methane through carbon monoxide emission, which decreased the oxidation capacity of the atmosphere. There were also large regional changes to tropospheric ozone concentrations, but contrasting effects of fire and meteorology resulted in a small change to global radiative forcing.
Chong Wang, Mingjiao Jia, Haiyun Xia, Yunbin Wu, Tianwen Wei, Xiang Shang, Chengyun Yang, Xianghui Xue, and Xiankang Dou
Atmos. Meas. Tech., 12, 3303–3315, https://doi.org/10.5194/amt-12-3303-2019, https://doi.org/10.5194/amt-12-3303-2019, 2019
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To investigate the relationship between BLH and air pollution under different conditions, a compact micro-pulse lidar integrating both direct-detection lidar and coherent Doppler wind lidar is built. Evolution of atmospheric boundary layer height (BLH), aerosol layer and fine structure in cloud base are well retrieved. Negative correlation exists between BLH and PM2.5. Different trends show that the relationship between PM2.5 and BLH should be considered in different boundary layer categories.
Wen Yi, Xianghui Xue, Iain M. Reid, Damian J. Murphy, Chris M. Hall, Masaki Tsutsumi, Baiqi Ning, Guozhu Li, Robert A. Vincent, Jinsong Chen, Jianfei Wu, Tingdi Chen, and Xiankang Dou
Atmos. Chem. Phys., 19, 7567–7581, https://doi.org/10.5194/acp-19-7567-2019, https://doi.org/10.5194/acp-19-7567-2019, 2019
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The seasonal variations in the mesopause densities, especially with regard to its global structure, are still unclear. In this study, we report the climatology of the mesopause density estimated using multiyear observations from nine meteor radars from Arctic to Antarctic latitudes. The results reveal a significant AO and SAO in mesopause density, an asymmetry between the two polar regions and evidence of intraseasonal oscillations (ISOs), perhaps associated with the ISOs of the troposphere.
Mario Nachbar, Henrike Wilms, Denis Duft, Tasha Aylett, Kensei Kitajima, Takuya Majima, John M. C. Plane, Markus Rapp, and Thomas Leisner
Atmos. Chem. Phys., 19, 4311–4322, https://doi.org/10.5194/acp-19-4311-2019, https://doi.org/10.5194/acp-19-4311-2019, 2019
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Polar mesospheric clouds (PMC) are water ice clouds forming on nanoparticles in the polar summer mesopause. We investigate the impact of solar radiation on PMC formation in the laboratory. We show that Mie theory calculations combined with an equilibrium temperature model presented in this work predict the warming of the particles very well. Using this model we demonstrate that the impact of solar radiation on ice particle formation is significantly lower than previously assumed.
Bingkun Yu, Xianghui Xue, Xin'an Yue, Chengyun Yang, Chao Yu, Xiankang Dou, Baiqi Ning, and Lianhuan Hu
Atmos. Chem. Phys., 19, 4139–4151, https://doi.org/10.5194/acp-19-4139-2019, https://doi.org/10.5194/acp-19-4139-2019, 2019
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It reports the long-term climatology of the intensity of Es layers from COSMIC satellites. The global Es maps present high-resolution spatial distributions and seasonal dependence. It mainly occurs at mid-latitudes and polar regions. Based on wind shear theory, simulation results indicate the convergence of vertical ion velocity could partially explain the Es seasonal dependence and some disagreements between observations and simulations suggest other processes play roles in the Es variations.
Tao Yuan, Wuhu Feng, John M. C. Plane, and Daniel R. Marsh
Atmos. Chem. Phys., 19, 3769–3777, https://doi.org/10.5194/acp-19-3769-2019, https://doi.org/10.5194/acp-19-3769-2019, 2019
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The Na layer in the upper atmosphere is very sensitive to solar radiation and varies considerably during sunrise and sunset. In this paper, we use the lidar observations and an advanced model to investigate this process. We found that the variation is mostly due to the changes in several photochemical reactions involving Na compounds, especially NaHCO3. We also reveal that the Fe layer in the same region changes more quickly than the Na layer due to a faster reaction rate of FeOH to sunlight.
David E. Siskind, McArthur Jones Jr., Douglas P. Drob, John P. McCormack, Mark E. Hervig, Daniel R. Marsh, Martin G. Mlynczak, Scott M. Bailey, Astrid Maute, and Nicholas J. Mitchell
Ann. Geophys., 37, 37–48, https://doi.org/10.5194/angeo-37-37-2019, https://doi.org/10.5194/angeo-37-37-2019, 2019
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We use data from two NASA satellites and a general circulation model of the upper atmosphere to elucidate the key factors governing the abundance and diurnal variation of nitric oxide (NO) at near-solar minimum conditions and low latitudes. This has been difficult to do previously, because NO data are typically taken from satellites in sun-synchronous orbits, meaning that they only acquire data in fixed local times. We overcome this limitation through model simulations of the NO diurnal cycle.
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
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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
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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.
Joe McNorton, Chris Wilson, Manuel Gloor, Rob J. Parker, Hartmut Boesch, Wuhu Feng, Ryan Hossaini, and Martyn P. Chipperfield
Atmos. Chem. Phys., 18, 18149–18168, https://doi.org/10.5194/acp-18-18149-2018, https://doi.org/10.5194/acp-18-18149-2018, 2018
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Since 2007 atmospheric methane (CH4) has been unexpectedly increasing following a 6-year hiatus. We have used an atmospheric model to attribute regional sources and global sinks of CH4 using observations for the 2003–2015 period. Model results show the renewed growth is best explained by decreased atmospheric removal, decreased biomass burning emissions, and an increased energy sector (mainly from Africa–Middle East and Southern Asia–Oceania) and wetland emissions (mainly from northern Eurasia).
Bingkun Yu, Xianghui Xue, Chengling Kuo, Gaopeng Lu, Xiankang Dou, Qi Gao, Jianfei Wu, Mingjiao Jia, Chao Yu, and Xiushu Qie
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2018-1025, https://doi.org/10.5194/acp-2018-1025, 2018
Preprint withdrawn
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This paper explores the relationship between the intensifications of atomic sodium layer and Es layer in the Mesosphere/Lower Thermosphere (MLT) region (the earth's upper atmosphere at altitudes between 90 and 130 km above ground). The multi-instrument experiment of sodium lidar observations, ionospheric observations and sodium chemical simulations advances our understanding of the dynamical and chemical coupling processes in the mesosphere and ionosphere above thunderstorms.
John M. C. Plane, Wuhu Feng, Juan Carlos Gómez Martín, Michael Gerding, and Shikha Raizada
Atmos. Chem. Phys., 18, 14799–14811, https://doi.org/10.5194/acp-18-14799-2018, https://doi.org/10.5194/acp-18-14799-2018, 2018
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Meteoric ablation creates layers of metal atoms in the atmosphere around 90 km. Although Ca and Na have similar elemental abundances in most minerals found in the solar system, surprisingly the Ca abundance in the atmosphere is less than 1 % that of Na. This study uses a detailed chemistry model of Ca, largely based on laboratory kinetics measurements, in a whole-atmosphere model to show that the depletion is caused by inefficient ablation of Ca and the formation of stable molecular reservoirs.
Tao Li, Chao Ban, Xin Fang, Jing Li, Zhaopeng Wu, Wuhu Feng, John M. C. Plane, Jiangang Xiong, Daniel R. Marsh, Michael J. Mills, and Xiankang Dou
Atmos. Chem. Phys., 18, 11683–11695, https://doi.org/10.5194/acp-18-11683-2018, https://doi.org/10.5194/acp-18-11683-2018, 2018
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A total of 154 nights of observations by the USTC Na temperature and wind lidar (32° N, 117° E) suggest significant seasonal variability in the mesopause. Chemistry plays an important role in Na atom formation. More than half of the observed gravity wave (GW) momentum flux (MF), whose divergence determines the GW forcing, is induced by short-period (10 min–2 h) waves. The anticorrelation between MF and zonal wind (U) suggests strong filtering of short-period GWs by semiannual oscillation U.
Amanda C. Maycock, Katja Matthes, Susann Tegtmeier, Hauke Schmidt, Rémi Thiéblemont, Lon Hood, Hideharu Akiyoshi, Slimane Bekki, Makoto Deushi, Patrick Jöckel, Oliver Kirner, Markus Kunze, Marion Marchand, Daniel R. Marsh, Martine Michou, David Plummer, Laura E. Revell, Eugene Rozanov, Andrea Stenke, Yousuke Yamashita, and Kohei Yoshida
Atmos. Chem. Phys., 18, 11323–11343, https://doi.org/10.5194/acp-18-11323-2018, https://doi.org/10.5194/acp-18-11323-2018, 2018
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The 11-year solar cycle is an important driver of climate variability. Changes in incoming solar ultraviolet radiation affect atmospheric ozone, which in turn influences atmospheric temperatures. Constraining the impact of the solar cycle on ozone is therefore important for understanding climate variability. This study examines the representation of the solar influence on ozone in numerical models used to simulate past and future climate. We highlight important differences among model datasets.
Maarten Krol, Marco de Bruine, Lars Killaars, Huug Ouwersloot, Andrea Pozzer, Yi Yin, Frederic Chevallier, Philippe Bousquet, Prabir Patra, Dmitry Belikov, Shamil Maksyutov, Sandip Dhomse, Wuhu Feng, and Martyn P. Chipperfield
Geosci. Model Dev., 11, 3109–3130, https://doi.org/10.5194/gmd-11-3109-2018, https://doi.org/10.5194/gmd-11-3109-2018, 2018
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The TransCom inter-comparison project regularly carries out studies to quantify errors in simulated atmospheric transport. This paper presents the first results of an age of air (AoA) inter-comparison of six global transport models. Following a protocol, six models simulated five tracers from which atmospheric transport times can easily be deduced. Results highlight that inter-model differences associated with atmospheric transport are still large and require further analysis.
Koen Hendrickx, Linda Megner, Daniel R. Marsh, and Christine Smith-Johnsen
Atmos. Chem. Phys., 18, 9075–9089, https://doi.org/10.5194/acp-18-9075-2018, https://doi.org/10.5194/acp-18-9075-2018, 2018
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The mechanisms that produce, destroy and transport nitric oxide (NO) in the Antarctic mesosphere and lower thermosphere are investigated in AIM-SOFIE satellite observations and compared to SD-WACCM simulations. During winter, NO concentrations are most similar while the altitude of maximum NO number densities is most separated. Even though the rate of descent is similar in both datasets, the simulated descending NO flux is too low in concentration, which reflects a missing source of NO.
Jens-Uwe Grooß, Rolf Müller, Reinhold Spang, Ines Tritscher, Tobias Wegner, Martyn P. Chipperfield, Wuhu Feng, Douglas E. Kinnison, and Sasha Madronich
Atmos. Chem. Phys., 18, 8647–8666, https://doi.org/10.5194/acp-18-8647-2018, https://doi.org/10.5194/acp-18-8647-2018, 2018
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We investigate a discrepancy between model simulations and observations of HCl in the dark polar stratosphere. In early winter, the less-well-studied period of the onset of chlorine activation, observations show a much faster depletion of HCl than simulations of three models. This points to some unknown process that is currently not represented in the models. Various hypotheses for potential causes are investigated that partly reduce the discrepancy. The impact on polar ozone depletion is low.
Richard J. Pope, Martyn P. Chipperfield, Stephen R. Arnold, Norbert Glatthor, Wuhu Feng, Sandip S. Dhomse, Brian J. Kerridge, Barry G. Latter, and Richard Siddans
Atmos. Chem. Phys., 18, 8389–8408, https://doi.org/10.5194/acp-18-8389-2018, https://doi.org/10.5194/acp-18-8389-2018, 2018
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
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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.
Alexander D. James, James S. A. Brooke, Thomas P. Mangan, Thomas F. Whale, John M. C. Plane, and Benjamin J. Murray
Atmos. Chem. Phys., 18, 4519–4531, https://doi.org/10.5194/acp-18-4519-2018, https://doi.org/10.5194/acp-18-4519-2018, 2018
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Crystal nucleation in polar stratospheric clouds (PSCs) has a direct impact on stratospheric chemistry and ozone. However, the mechanism of nucleation has been unclear for decades, limiting prediction of the response of ozone to atmospheric changes. We experimentally demonstrate that meteoric material can trigger nucleation heterogeneously and this can produce observed crystal concentrations in PSCs. This discovery paves the way to robust modelling of past and future trends in PSCs and ozone.
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.
Sarah A. Monks, Stephen R. Arnold, Michael J. Hollaway, Richard J. Pope, Chris Wilson, Wuhu Feng, Kathryn M. Emmerson, Brian J. Kerridge, Barry L. Latter, Georgina M. Miles, Richard Siddans, and Martyn P. Chipperfield
Geosci. Model Dev., 10, 3025–3057, https://doi.org/10.5194/gmd-10-3025-2017, https://doi.org/10.5194/gmd-10-3025-2017, 2017
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The TOMCAT chemical transport model has been updated with the chemical degradation of ethene, propene, toluene, butane and monoterpenes. The tropospheric chemical mechanism is documented and the model is evaluated against surface, balloon, aircraft and satellite data. The model is generally able to capture the main spatial and seasonal features of carbon monoxide, ozone, volatile organic compounds and reactive nitrogen. However,
some model biases are found that require further investigation.
Katja Matthes, Bernd Funke, Monika E. Andersson, Luke Barnard, Jürg Beer, Paul Charbonneau, Mark A. Clilverd, Thierry Dudok de Wit, Margit Haberreiter, Aaron Hendry, Charles H. Jackman, Matthieu Kretzschmar, Tim Kruschke, Markus Kunze, Ulrike Langematz, Daniel R. Marsh, Amanda C. Maycock, Stergios Misios, Craig J. Rodger, Adam A. Scaife, Annika Seppälä, Ming Shangguan, Miriam Sinnhuber, Kleareti Tourpali, Ilya Usoskin, Max van de Kamp, Pekka T. Verronen, and Stefan Versick
Geosci. Model Dev., 10, 2247–2302, https://doi.org/10.5194/gmd-10-2247-2017, https://doi.org/10.5194/gmd-10-2247-2017, 2017
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The solar forcing dataset for climate model experiments performed for the upcoming IPCC report is described. This dataset provides the radiative and particle input of solar variability on a daily basis from 1850 through to 2300. With this dataset a better representation of natural climate variability with respect to the output of the Sun is provided which provides the most sophisticated and comprehensive respresentation of solar variability that has been used in climate model simulations so far.
Wenshou Tian, Yuanpu Li, Fei Xie, Jiankai Zhang, Martyn P. Chipperfield, Wuhu Feng, Yongyun Hu, Sen Zhao, Xin Zhou, Yun Yang, and Xuan Ma
Atmos. Chem. Phys., 17, 6705–6722, https://doi.org/10.5194/acp-17-6705-2017, https://doi.org/10.5194/acp-17-6705-2017, 2017
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Although the principal mechanisms responsible for the formation of the Antarctic ozone hole are well understood, the factors or processes that generate interannual variations in ozone levels in the southern high-latitude stratosphere remain under debate. This study finds that the SST variations across the East Asian marginal seas (5° S–35° N, 100–140° E) could modulate the southern high-latitude stratospheric ozone interannual changes.
Stefanie Unterguggenberger, Stefan Noll, Wuhu Feng, John M. C. Plane, Wolfgang Kausch, Stefan Kimeswenger, Amy Jones, and Sabine Moehler
Atmos. Chem. Phys., 17, 4177–4187, https://doi.org/10.5194/acp-17-4177-2017, https://doi.org/10.5194/acp-17-4177-2017, 2017
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This study focuses on the analysis of astronomical medium-resolution spectra from the VLT in Chile to measure airglow pseudo-continuum emission of FeO in the optical regime. Compared to OH or Na emissions, this emission is difficult to measure. Using 3.5 years of spectroscopic data, we found annual and semi-annual variations of the FeO emission. Furthermore, we used WACCM to determine the quantum yield of the FeO-producing Fe + O3 reaction in the atmosphere, which has not been done before.
Jochen Stutz, Bodo Werner, Max Spolaor, Lisa Scalone, James Festa, Catalina Tsai, Ross Cheung, Santo F. Colosimo, Ugo Tricoli, Rasmus Raecke, Ryan Hossaini, Martyn P. Chipperfield, Wuhu Feng, Ru-Shan Gao, Eric J. Hintsa, James W. Elkins, Fred L. Moore, Bruce Daube, Jasna Pittman, Steven Wofsy, and Klaus Pfeilsticker
Atmos. Meas. Tech., 10, 1017–1042, https://doi.org/10.5194/amt-10-1017-2017, https://doi.org/10.5194/amt-10-1017-2017, 2017
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A new limb-scanning Differential Optical Absorption Spectroscopy (DOAS) instrument was developed for NASA’s Global Hawk unmanned aerial system during the Airborne Tropical TRopopause EXperiment to study trace gases in the tropical tropopause layer. A new technique that uses in situ and DOAS O3 observations together with radiative transfer calculations allows the retrieval of mixing ratios from the slant column densities of BrO and NO2 at high accuracies of 0.5 ppt and 15 ppt, respectively.
Bernd Funke, William Ball, Stefan Bender, Angela Gardini, V. Lynn Harvey, Alyn Lambert, Manuel López-Puertas, Daniel R. Marsh, Katharina Meraner, Holger Nieder, Sanna-Mari Päivärinta, Kristell Pérot, Cora E. Randall, Thomas Reddmann, Eugene Rozanov, Hauke Schmidt, Annika Seppälä, Miriam Sinnhuber, Timofei Sukhodolov, Gabriele P. Stiller, Natalia D. Tsvetkova, Pekka T. Verronen, Stefan Versick, Thomas von Clarmann, Kaley A. Walker, and Vladimir Yushkov
Atmos. Chem. Phys., 17, 3573–3604, https://doi.org/10.5194/acp-17-3573-2017, https://doi.org/10.5194/acp-17-3573-2017, 2017
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Simulations from eight atmospheric models have been compared to tracer and temperature observations from seven satellite instruments in order to evaluate the energetic particle indirect effect (EPP IE) during the perturbed northern hemispheric (NH) winter 2008/2009. Models are capable to reproduce the EPP IE in dynamically and geomagnetically quiescent NH winter conditions. The results emphasize the need for model improvements in the dynamical representation of elevated stratopause events.
Xuguang Cai, Tao Yuan, and Han-Li Liu
Ann. Geophys., 35, 181–188, https://doi.org/10.5194/angeo-35-181-2017, https://doi.org/10.5194/angeo-35-181-2017, 2017
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Atmospheric gravity waves play highly important roles in the dynamic and chemical processes in the upper atmosphere. To assess their magnitude, continuous full diurnal cycle measurements of temperature perturbations are necessary. In this paper we have calculated the large-scale gravity wave modulations between 85 and 99 km altitude based on the measurements by a unique Na lidar at Utah State University in the month of September from 2011 to 2015. The waves with period of 3–5 h dominate.
Tamás Kovács, Wuhu Feng, Anna Totterdill, John M. C. Plane, Sandip Dhomse, Juan Carlos Gómez-Martín, Gabriele P. Stiller, Florian J. Haenel, Christopher Smith, Piers M. Forster, Rolando R. García, Daniel R. Marsh, and Martyn P. Chipperfield
Atmos. Chem. Phys., 17, 883–898, https://doi.org/10.5194/acp-17-883-2017, https://doi.org/10.5194/acp-17-883-2017, 2017
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Sulfur hexafluoride (SF6) is a very potent greenhouse gas, which is present in the atmosphere only through its industrial use, for example as an electrical insulator. To estimate accurately the impact of SF6 emissions on climate we need to know how long it persists in the atmosphere before being removed. Previous estimates of the SF6 lifetime indicate a large degree of uncertainty. Here we use a detailed atmospheric model to calculate a current best estimate of the SF6 lifetime.
Martyn P. Chipperfield, Qing Liang, Matthew Rigby, Ryan Hossaini, Stephen A. Montzka, Sandip Dhomse, Wuhu Feng, Ronald G. Prinn, Ray F. Weiss, Christina M. Harth, Peter K. Salameh, Jens Mühle, Simon O'Doherty, Dickon Young, Peter G. Simmonds, Paul B. Krummel, Paul J. Fraser, L. Paul Steele, James D. Happell, Robert C. Rhew, James Butler, Shari A. Yvon-Lewis, Bradley Hall, David Nance, Fred Moore, Ben R. Miller, James W. Elkins, Jeremy J. Harrison, Chris D. Boone, Elliot L. Atlas, and Emmanuel Mahieu
Atmos. Chem. Phys., 16, 15741–15754, https://doi.org/10.5194/acp-16-15741-2016, https://doi.org/10.5194/acp-16-15741-2016, 2016
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Carbon tetrachloride (CCl4) is a compound which, when released into the atmosphere, can cause depletion of the stratospheric ozone layer. Its emissions are controlled under the Montreal Protocol, and its atmospheric abundance is slowly decreasing. However, this decrease is not as fast as expected based on estimates of its emissions and its atmospheric lifetime. We have used an atmospheric model to look at the uncertainties in the CCl4 lifetime and to examine the impact on its atmospheric decay.
Alfonso Saiz-Lopez, John M. C. Plane, Carlos A. Cuevas, Anoop S. Mahajan, Jean-François Lamarque, and Douglas E. Kinnison
Atmos. Chem. Phys., 16, 15593–15604, https://doi.org/10.5194/acp-16-15593-2016, https://doi.org/10.5194/acp-16-15593-2016, 2016
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Electronic structure calculations are used to survey possible reactions that HOI and I2 could undergo at night in the lower troposphere, and hence reconcile measurements and models. The reactions NO3 + HOI and I2 + NO3 are included in two models to explore a new nocturnal iodine radical activation mechanism, leading to a reduction of nighttime HOI and I2. This chemistry can have a large impact on NO3 levels in the MBL, and hence upon the nocturnal oxidizing capacity of the marine atmosphere.
Wayne K. Hocking, Reynold E. Silber, John M. C. Plane, Wuhu Feng, and Marcial Garbanzo-Salas
Ann. Geophys., 34, 1119–1144, https://doi.org/10.5194/angeo-34-1119-2016, https://doi.org/10.5194/angeo-34-1119-2016, 2016
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Meteoroids entering the atmosphere produce trails of ionized particles which can be detected with radar. The weakest ones are called underdense (the most common), the strongest are called overdense, and intermediate ones are transitional. Meteor radar signatures are used to determine atmospheric parameters like temperature and winds. We present new results which show the effect of ozone on the transitional trail lifetimes, which may eventually allow radar to measure mesospheric ozone.
Richard J. Pope, Nigel A. D. Richards, Martyn P. Chipperfield, David P. Moore, Sarah A. Monks, Stephen R. Arnold, Norbert Glatthor, Michael Kiefer, Tom J. Breider, Jeremy J. Harrison, John J. Remedios, Carsten Warneke, James M. Roberts, Glenn S. Diskin, Lewis G. Huey, Armin Wisthaler, Eric C. Apel, Peter F. Bernath, and Wuhu Feng
Atmos. Chem. Phys., 16, 13541–13559, https://doi.org/10.5194/acp-16-13541-2016, https://doi.org/10.5194/acp-16-13541-2016, 2016
Anna Totterdill, Tamás Kovács, Wuhu Feng, Sandip Dhomse, Christopher J. Smith, Juan Carlos Gómez-Martín, Martyn P. Chipperfield, Piers M. Forster, and John M. C. Plane
Atmos. Chem. Phys., 16, 11451–11463, https://doi.org/10.5194/acp-16-11451-2016, https://doi.org/10.5194/acp-16-11451-2016, 2016
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In this study we have experimentally determined the infrared absorption cross sections of NF3 and CFC-115, calculated the radiative forcing and efficiency using two radiative transfer models and identified the effect of clouds and stratospheric adjustment. We have also determined their atmospheric lifetimes using the Whole Atmosphere Community Climate Model.
Tamás Kovács, John M. C. Plane, Wuhu Feng, Tibor Nagy, Martyn P. Chipperfield, Pekka T. Verronen, Monika E. Andersson, David A. Newnham, Mark A. Clilverd, and Daniel R. Marsh
Geosci. Model Dev., 9, 3123–3136, https://doi.org/10.5194/gmd-9-3123-2016, https://doi.org/10.5194/gmd-9-3123-2016, 2016
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This study was completed on D-region atmospheric model development. The sophisticated 3-D Whole Atmosphere Community Climate Model (WACCM) and the 1-D Sodynkalä Ion and Neutral Chemistry Model (SIC) were combined in order to provide a detailed, accurate model (WACCM-SIC) that considers the processes taking place in solar proton events. The original SIC model was reduced by mechanism reduction, which provided an accurate sub-mechanism (rSIC, WACCM-rSIC) of the original model.
Simone Tilmes, Jean-Francois Lamarque, Louisa K. Emmons, Doug E. Kinnison, Dan Marsh, Rolando R. Garcia, Anne K. Smith, Ryan R. Neely, Andrew Conley, Francis Vitt, Maria Val Martin, Hiroshi Tanimoto, Isobel Simpson, Don R. Blake, and Nicola Blake
Geosci. Model Dev., 9, 1853–1890, https://doi.org/10.5194/gmd-9-1853-2016, https://doi.org/10.5194/gmd-9-1853-2016, 2016
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The state of the art Community Earth System Model, CESM1 CAM4-chem has been used to perform reference and sensitivity simulations as part of the Chemistry Climate Model Initiative (CCMI). Specifics of the model and details regarding the setup of the simulations are described. In additions, the main behavior of the model, including selected chemical species have been evaluated with climatological datasets. This paper is therefore a references for studies that use the provided model results.
Charles H. Jackman, Daniel R. Marsh, Douglas E. Kinnison, Christopher J. Mertens, and Eric L. Fleming
Atmos. Chem. Phys., 16, 5853–5866, https://doi.org/10.5194/acp-16-5853-2016, https://doi.org/10.5194/acp-16-5853-2016, 2016
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Two global models were used to investigate the impact of galactic cosmic ray (GCRs) on the atmosphere over the 1960-2010 time period. The primary impact of the naturally occurring GCRs on ozone was found to be due to their production of NOx and this impact varies with the atmospheric chlorine loading, sulfate aerosol loading, and solar cycle variation. GCR-caused decreases of annual average global total ozone were computed to be 0.2 % or less.
Sheng-Yang Gu, Han-Li Liu, Xiankang Dou, and Tao Li
Atmos. Chem. Phys., 16, 4885–4896, https://doi.org/10.5194/acp-16-4885-2016, https://doi.org/10.5194/acp-16-4885-2016, 2016
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The influences of sudden stratospheric warming in the Northern Hemisphere on quasi-2-day waves are studied with both observations and simulations. We found the energy of W3 is transferred to W2 through the nonlinear interaction with SPW1 and the instability at winter mesopause could provide additional amplification for W3. The summer easterly is enhanced during SSW, which is more favorable for the propagation of quasi-2-day waves.
N. S. Umo, B. J. Murray, M. T. Baeza-Romero, J. M. Jones, A. R. Lea-Langton, T. L. Malkin, D. O'Sullivan, L. Neve, J. M. C. Plane, and A. Williams
Atmos. Chem. Phys., 15, 5195–5210, https://doi.org/10.5194/acp-15-5195-2015, https://doi.org/10.5194/acp-15-5195-2015, 2015
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Combustion ash particles nucleate ice in the immersion mode at conditions relevant to mixed-phase clouds. Hence, combustion ashes could play an important role in primary ice formation in mixed-phase clouds, especially in clouds that are formed near the emission source of these aerosol particles. From this study, there is a need to quantify the atmospheric abundance of combustion ashes in order to quantitatively assess the impact of combustion ashes on mixed-phase clouds.
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.
X. Yue, W. S. Schreiner, Z. Zeng, Y.-H. Kuo, and X. Xue
Atmos. Meas. Tech., 8, 225–236, https://doi.org/10.5194/amt-8-225-2015, https://doi.org/10.5194/amt-8-225-2015, 2015
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The occurrence of sporadic E (Es) layers has been a hot scientific topic for a long time. GNSS (global navigation satellite system)-based radio occultation (RO) has proven to be a powerful technique for detecting the global Es layers. In this paper, we show some examples of multiple Es layers occurring in one RO event and the occurrence of Es in a broad region during a certain time interval. The results are then evaluated by independent observations such as lidar and ionosondes.
H. Berresheim, M. Adam, C. Monahan, C. O'Dowd, J. M. C. Plane, B. Bohn, and F. Rohrer
Atmos. Chem. Phys., 14, 12209–12223, https://doi.org/10.5194/acp-14-12209-2014, https://doi.org/10.5194/acp-14-12209-2014, 2014
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Sulfuric acid plays a major role in the formation of aerosol particles and clouds. Measurements at the west coast of Ireland reveal that oxidation of SO2 by OH explains only 20%, on average, of H2SO4 formation in coastal marine air. Additional sources may be (a) oxidation by Criegee intermediates produced photolytically and/or (b) formation from SO3 instead of SO2 in the oxidation of dimethyl sulfide, suggesting an important role of marine emissions in the self-cleaning power of the atmosphere.
Y. J. Liu, J. M. C. Plane, B. R. Clemesha, J. H. Wang, and X. W. Cheng
Ann. Geophys., 32, 1321–1332, https://doi.org/10.5194/angeo-32-1321-2014, https://doi.org/10.5194/angeo-32-1321-2014, 2014
A. Spolaor, P. Vallelonga, J. Gabrieli, T. Martma, M. P. Björkman, E. Isaksson, G. Cozzi, C. Turetta, H. A. Kjær, M. A. J. Curran, A. D. Moy, A. Schönhardt, A.-M. Blechschmidt, J. P. Burrows, J. M. C. Plane, and C. Barbante
Atmos. Chem. Phys., 14, 9613–9622, https://doi.org/10.5194/acp-14-9613-2014, https://doi.org/10.5194/acp-14-9613-2014, 2014
S. M. MacDonald, J. C. Gómez Martín, R. Chance, S. Warriner, A. Saiz-Lopez, L. J. Carpenter, and J. M. C. Plane
Atmos. Chem. Phys., 14, 5841–5852, https://doi.org/10.5194/acp-14-5841-2014, https://doi.org/10.5194/acp-14-5841-2014, 2014
G. Chiodo, D. R. Marsh, R. Garcia-Herrera, N. Calvo, and J. A. García
Atmos. Chem. Phys., 14, 5251–5269, https://doi.org/10.5194/acp-14-5251-2014, https://doi.org/10.5194/acp-14-5251-2014, 2014
X. Liu, J. Xu, H.-L. Liu, J. Yue, and W. Yuan
Ann. Geophys., 32, 543–552, https://doi.org/10.5194/angeo-32-543-2014, https://doi.org/10.5194/angeo-32-543-2014, 2014
A. C. Kren, D. R. Marsh, A. K. Smith, and P. Pilewskie
Atmos. Chem. Phys., 14, 4843–4856, https://doi.org/10.5194/acp-14-4843-2014, https://doi.org/10.5194/acp-14-4843-2014, 2014
A. Spolaor, J. Gabrieli, T. Martma, J. Kohler, M. B. Björkman, E. Isaksson, C. Varin, P. Vallelonga, J. M. C. Plane, and C. Barbante
The Cryosphere, 7, 1645–1658, https://doi.org/10.5194/tc-7-1645-2013, https://doi.org/10.5194/tc-7-1645-2013, 2013
A. Spolaor, P. Vallelonga, J. M. C. Plane, N. Kehrwald, J. Gabrieli, C. Varin, C. Turetta, G. Cozzi, R. Kumar, C. Boutron, and C. Barbante
Atmos. Chem. Phys., 13, 6623–6635, https://doi.org/10.5194/acp-13-6623-2013, https://doi.org/10.5194/acp-13-6623-2013, 2013
M. Rapp, J. M. C. Plane, B. Strelnikov, G. Stober, S. Ernst, J. Hedin, M. Friedrich, and U.-P. Hoppe
Ann. Geophys., 30, 1661–1673, https://doi.org/10.5194/angeo-30-1661-2012, https://doi.org/10.5194/angeo-30-1661-2012, 2012
A. S. Mahajan, J. C. Gómez Martín, T. D. Hay, S.-J. Royer, S. Yvon-Lewis, Y. Liu, L. Hu, C. Prados-Roman, C. Ordóñez, J. M. C. Plane, and A. Saiz-Lopez
Atmos. Chem. Phys., 12, 11609–11617, https://doi.org/10.5194/acp-12-11609-2012, https://doi.org/10.5194/acp-12-11609-2012, 2012
Related subject area
Subject: Dynamics | Research Activity: Atmospheric Modelling and Data Analysis | Altitude Range: Mesosphere | Science Focus: Physics (physical properties and processes)
Effects of nonmigrating diurnal tides on the Na layer in the mesosphere and lower thermosphere
Observation and simulation of neutral air density in the middle atmosphere during the 2021 sudden stratospheric warming event
Studies on the propagation dynamics and source mechanism of quasi-monochromatic gravity waves observed over São Martinho da Serra (29° S, 53° W), Brazil
Quasi-10 d wave activity in the southern high-latitude mesosphere and lower thermosphere (MLT) region and its relation to large-scale instability and gravity wave drag
Impact of a strong volcanic eruption on the summer middle atmosphere in UA-ICON simulations
Simulated long-term evolution of the thermosphere during the Holocene – Part 2: Circulation and solar tides
Simulated long-term evolution of the thermosphere during the Holocene – Part 1: Neutral density and temperature
Numerical modelling of relative contribution of planetary waves to the atmospheric circulation
Decay times of atmospheric acoustic–gravity waves after deactivation of wave forcing
Suppressed migrating diurnal tides in the mesosphere and lower thermosphere region during El Niño in northern winter and its possible mechanism
Intercomparison of middle atmospheric meteorological analyses for the Northern Hemisphere winter 2009–2010
Does the coupling of the semiannual oscillation with the quasi-biennial oscillation provide predictability of Antarctic sudden stratospheric warmings?
The sporadic sodium layer: a possible tracer for the conjunction between the upper and lower atmospheres
Modelled effects of temperature gradients and waves on the hydroxyl rotational distribution in ground-based airglow measurements
A study of the dynamical characteristics of inertia–gravity waves in the Antarctic mesosphere combining the PANSY radar and a non-hydrostatic general circulation model
Forcing mechanisms of the terdiurnal tide
Local time dependence of polar mesospheric clouds: a model study
The role of the winter residual circulation in the summer mesopause regions in WACCM
Influence of the sudden stratospheric warming on quasi-2-day waves
On the impact of the temporal variability of the collisional quenching process on the mesospheric OH emission layer: a study based on SD-WACCM4 and SABER
Environmental influences on the intensity changes of tropical cyclones over the western North Pacific
Modeling of very low frequency (VLF) radio wave signal profile due to solar flares using the GEANT4 Monte Carlo simulation coupled with ionospheric chemistry
The genesis of Typhoon Nuri as observed during the Tropical Cyclone Structure 2008 (TCS08) field experiment – Part 2: Observations of the convective environment
CO at 40–80 km above Kiruna observed by the ground-based microwave radiometer KIMRA and simulated by the Whole Atmosphere Community Climate Model
Jianfei Wu, Wuhu Feng, Xianghui Xue, Daniel Robert Marsh, and John Maurice Campbell Plane
Atmos. Chem. Phys., 24, 12133–12141, https://doi.org/10.5194/acp-24-12133-2024, https://doi.org/10.5194/acp-24-12133-2024, 2024
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Metal layers occur in the mesosphere and lower thermosphere region 80–120 km from the ablation of cosmic dust. Nonmigrating diurnal tides are persistent global oscillations. We investigate nonmigrating diurnal tidal variations in metal layers using satellite observations and global climate model simulations; these have not been studied previously due to the limitations of measurements. The nonmigrating diurnal tides in temperature are strongly linked to the corresponding change in metal layers.
Junfeng Yang, Jianmei Wang, Dan Liu, Wenjie Guo, and Yiming Zhang
Atmos. Chem. Phys., 24, 10113–10127, https://doi.org/10.5194/acp-24-10113-2024, https://doi.org/10.5194/acp-24-10113-2024, 2024
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Atmospheric drag may vary dramatically under the influence of atmospheric density over aircraft flights at 20–100 km. This indicates that the natural density evolution needs to be analyzed. However, the middle-atmospheric density response to sudden stratospheric warming (SSW) events has rarely been reported. In this study, the density distribution and mass transport process are illustrated based on observation data and global numerical model simulations during the 2021 major SSW event.
Cristiano M. Wrasse, Prosper K. Nyassor, Ligia A. da Silva, Cosme A. O. B. Figueiredo, José V. Bageston, Kleber P. Naccarato, Diego Barros, Hisao Takahashi, and Delano Gobbi
Atmos. Chem. Phys., 24, 5405–5431, https://doi.org/10.5194/acp-24-5405-2024, https://doi.org/10.5194/acp-24-5405-2024, 2024
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This present work investigates the propagation dynamics and the sources–source mechanisms of quasi-monochromatic gravity waves (QMGWs) observed between April 2017 and April 2022 at São Martinho da Serra. The QMGW parameters were estimated using a 2D spectral analysis, and their source locations were identified using a backward ray-tracing model. Furthermore, the propagation conditions, sources, and source mechanisms of the QMGWs were extensively studied.
Wonseok Lee, In-Sun Song, Byeong-Gwon Song, and Yong Ha Kim
Atmos. Chem. Phys., 24, 3559–3575, https://doi.org/10.5194/acp-24-3559-2024, https://doi.org/10.5194/acp-24-3559-2024, 2024
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We investigate the seasonal variation of westward-propagating quasi-10 d wave (Q10DW) activity in the southern high-latitude mesosphere. The observed Q10DW is amplified around equinoxes. The model experiments indicate that the Q10DW can be enhanced in the high-latitude mesosphere due to large-scale instability. However, an excessively strong instability in the summer mesosphere spuriously generates the Q10DW in the model, potentially leading to inaccurate model dynamics.
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.
Xu Zhou, Xinan Yue, Yihui Cai, Zhipeng Ren, Yong Wei, and Yongxin Pan
Atmos. Chem. Phys., 23, 6383–6393, https://doi.org/10.5194/acp-23-6383-2023, https://doi.org/10.5194/acp-23-6383-2023, 2023
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Secular variations in CO2 concentration and geomagnetic field can affect the dynamics of the upper atmosphere. We examine how these two factors influence the dynamics of the upper atmosphere during the Holocene, using two sets of ~ 12 000-year control runs by the coupled thermosphere–ionosphere model. The main results show that (a) increased CO2 enhances the thermospheric circulation, but non-linearly; and (b) geomagnetic variation induced a significant hemispheric asymmetrical effect.
Yihui Cai, Xinan Yue, Xu Zhou, Zhipeng Ren, Yong Wei, and Yongxin Pan
Atmos. Chem. Phys., 23, 5009–5021, https://doi.org/10.5194/acp-23-5009-2023, https://doi.org/10.5194/acp-23-5009-2023, 2023
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On timescales longer than the solar cycle, secular changes in CO2 concentration and geomagnetic field play a key role in influencing the thermosphere. We performed four sets of ~12000-year control runs with the coupled thermosphere–ionosphere model to examine the effects of the geomagnetic field, CO2, and solar activity on thermospheric density and temperature, deepening our understanding of long-term changes in the thermosphere and making projections for future thermospheric changes.
Andrey V. Koval, Olga N. Toptunova, Maxim A. Motsakov, Ksenia A. Didenko, Tatiana S. Ermakova, Nikolai M. Gavrilov, and Eugene V. Rozanov
Atmos. Chem. Phys., 23, 4105–4114, https://doi.org/10.5194/acp-23-4105-2023, https://doi.org/10.5194/acp-23-4105-2023, 2023
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Periodic changes in all hydrodynamic parameters are constantly observed in the atmosphere. The amplitude of these fluctuations increases with height due to a decrease in the atmospheric density. In the upper layers of the atmosphere, waves are the dominant form of motion. We use a model of the general circulation of the atmosphere to study the contribution to the formation of the dynamic and temperature regimes of the middle and upper atmosphere made by different global-scale atmospheric waves.
Nikolai M. Gavrilov, Sergey P. Kshevetskii, and Andrey V. Koval
Atmos. Chem. Phys., 22, 13713–13724, https://doi.org/10.5194/acp-22-13713-2022, https://doi.org/10.5194/acp-22-13713-2022, 2022
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We make high-resolution simulations of poorly understood decays of nonlinear atmospheric acoustic–gravity waves (AGWs) after deactivations of the wave forcing. The standard deviations of AGW perturbations, after fast dispersions of traveling modes, experience slower exponential decreases. AGW decay times are estimated for the first time and are 20–100 h in the stratosphere and mesosphere. This requires slow, quasi-standing and secondary modes in parameterizations of AGW impacts to be considered.
Yetao Cen, Chengyun Yang, Tao Li, James M. Russell III, and Xiankang Dou
Atmos. Chem. Phys., 22, 7861–7874, https://doi.org/10.5194/acp-22-7861-2022, https://doi.org/10.5194/acp-22-7861-2022, 2022
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The MLT DW1 amplitude is suppressed during El Niño winters in both satellite observation and SD-WACCM simulations. The suppressed Hough mode (1, 1) in the tropopause region propagates vertically to the MLT region, leading to decreased DW1 amplitude. The latitudinal zonal wind shear anomalies during El Niño winters would narrow the waveguide and prevent the vertical propagation of DW1. The gravity wave drag excited by ENSO-induced anomalous convection could also modulate the MLT DW1 amplitude.
John P. McCormack, V. Lynn Harvey, Cora E. Randall, Nicholas Pedatella, Dai Koshin, Kaoru Sato, Lawrence Coy, Shingo Watanabe, Fabrizio Sassi, and Laura A. Holt
Atmos. Chem. Phys., 21, 17577–17605, https://doi.org/10.5194/acp-21-17577-2021, https://doi.org/10.5194/acp-21-17577-2021, 2021
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In order to have confidence in atmospheric predictions, it is important to know how well different numerical model simulations of the Earth’s atmosphere agree with one another. This work compares four different data assimilation models that extend to or beyond the mesosphere. Results shown here demonstrate that while the models are in close agreement below ~50 km, large differences arise at higher altitudes in the mesosphere and lower thermosphere that will need to be reconciled in the future.
Viktoria J. Nordström and Annika Seppälä
Atmos. Chem. Phys., 21, 12835–12853, https://doi.org/10.5194/acp-21-12835-2021, https://doi.org/10.5194/acp-21-12835-2021, 2021
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The winter winds over Antarctica form a stable vortex. However, in 2019 the vortex was disrupted and the temperature in the polar stratosphere rose by 50°C. This event, called a sudden stratospheric warming, is a rare event in the Southern Hemisphere, with the only known major event having taken place in 2002. The 2019 event helps us unravel its causes, which are largely unknown. We have discovered a unique behaviour of the equatorial winds in 2002 and 2019 that may signal an impending SH SSW.
Shican Qiu, Ning Wang, Willie Soon, Gaopeng Lu, Mingjiao Jia, Xingjin Wang, Xianghui Xue, Tao Li, and Xiankang Dou
Atmos. Chem. Phys., 21, 11927–11940, https://doi.org/10.5194/acp-21-11927-2021, https://doi.org/10.5194/acp-21-11927-2021, 2021
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Our results suggest that lightning strokes would probably influence the ionosphere and thus give rise to the occurrence of a sporadic sodium layer (NaS), with the overturning of the electric field playing an important role. Model simulation results show that the calculated first-order rate coefficient could explain the efficient recombination of Na+→Na in this NaS case study. A conjunction between the lower and upper atmospheres could be established by these inter-connected phenomena.
Christoph Franzen, Patrick Joseph Espy, and Robert Edward Hibbins
Atmos. Chem. Phys., 20, 333–343, https://doi.org/10.5194/acp-20-333-2020, https://doi.org/10.5194/acp-20-333-2020, 2020
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Ground-based observations of the hydroxyl (OH) airglow have indicated that the rotational energy levels may not be in thermal equilibrium with the surrounding gas. Here we use simulations of the OH airglow to show that temperature changes across the extended airglow layer, either climatological or those temporarily caused by atmospheric waves, can mimic this effect for thermalized OH. Thus, these must be considered in order to quantify the non-thermal nature of the OH airglow.
Ryosuke Shibuya and Kaoru Sato
Atmos. Chem. Phys., 19, 3395–3415, https://doi.org/10.5194/acp-19-3395-2019, https://doi.org/10.5194/acp-19-3395-2019, 2019
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The first long-term simulation using the high-top non-hydrostatic general circulation model (NICAM) was executed to analyze mesospheric gravity waves. A new finding in this paper is that the spectrum of the vertical fluxes of the zonal momentum has an isolated peak at frequencies slightly lower than f at latitudes from 30 to 75° S at a height of 70 km. This study discusses the physical mechanism for an explanation of the existence of the isolated spectrum peak in the mesosphere.
Friederike Lilienthal, Christoph Jacobi, and Christoph Geißler
Atmos. Chem. Phys., 18, 15725–15742, https://doi.org/10.5194/acp-18-15725-2018, https://doi.org/10.5194/acp-18-15725-2018, 2018
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The terdiurnal solar tide is an atmospheric wave, owing to the daily variation of solar heating with a period of 8 h. Here, we present model simulations of this tide and investigate the relative importance of possible forcing mechanisms because they are still under debate. These are, besides direct solar heating, nonlinear interactions between other tides and gravity wave–tide interactions. As a result, solar heating is most important and nonlinear effects partly counteract this forcing.
Francie Schmidt, Gerd Baumgarten, Uwe Berger, Jens Fiedler, and Franz-Josef Lübken
Atmos. Chem. Phys., 18, 8893–8908, https://doi.org/10.5194/acp-18-8893-2018, https://doi.org/10.5194/acp-18-8893-2018, 2018
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Local time variations of polar mesospheric clouds (PMCs) in the Northern Hemisphere are studied using a combination of a global circulation model and a microphysical model. We investigate the brightness, altitude, and occurrence of the clouds and find a good agreement between model and observations. The variations are caused by tidal structures in background parameters. The temperature varies by about 2 K and water vapor by about 3 ppmv at the altitude of ice particle sublimation near 81.5 km.
Maartje Sanne Kuilman and Bodil Karlsson
Atmos. Chem. Phys., 18, 4217–4228, https://doi.org/10.5194/acp-18-4217-2018, https://doi.org/10.5194/acp-18-4217-2018, 2018
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In this study, we investigate the role of the winter residual circulation in the summer mesopause region using the Whole Atmosphere Community Climate Model. In addition, we study the role of the summer stratosphere in shaping the conditions of the summer polar mesosphere. We strengthen the evidence that the variability in the summer mesopause region is mainly driven by changes in the summer mesosphere rather than in the summer stratosphere.
Sheng-Yang Gu, Han-Li Liu, Xiankang Dou, and Tao Li
Atmos. Chem. Phys., 16, 4885–4896, https://doi.org/10.5194/acp-16-4885-2016, https://doi.org/10.5194/acp-16-4885-2016, 2016
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The influences of sudden stratospheric warming in the Northern Hemisphere on quasi-2-day waves are studied with both observations and simulations. We found the energy of W3 is transferred to W2 through the nonlinear interaction with SPW1 and the instability at winter mesopause could provide additional amplification for W3. The summer easterly is enhanced during SSW, which is more favorable for the propagation of quasi-2-day waves.
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
Shoujuan Shu, Fuqing Zhang, Jie Ming, and Yuan Wang
Atmos. Chem. Phys., 14, 6329–6342, https://doi.org/10.5194/acp-14-6329-2014, https://doi.org/10.5194/acp-14-6329-2014, 2014
S. Palit, T. Basak, S. K. Mondal, S. Pal, and S. K. Chakrabarti
Atmos. Chem. Phys., 13, 9159–9168, https://doi.org/10.5194/acp-13-9159-2013, https://doi.org/10.5194/acp-13-9159-2013, 2013
M. T. Montgomery and R. K. Smith
Atmos. Chem. Phys., 12, 4001–4009, https://doi.org/10.5194/acp-12-4001-2012, https://doi.org/10.5194/acp-12-4001-2012, 2012
C. G. Hoffmann, D. E. Kinnison, R. R. Garcia, M. Palm, J. Notholt, U. Raffalski, and G. Hochschild
Atmos. Chem. Phys., 12, 3261–3271, https://doi.org/10.5194/acp-12-3261-2012, https://doi.org/10.5194/acp-12-3261-2012, 2012
Cited articles
Banks, P. and Kockarts, G. (Eds.): Chapter 19 – Plasma Transport, in: Aeronomy, Academic Press, New York, 152–168, https://doi.org/10.1016/B978-0-12-077802-7.50011-7, 1973.
Bones, D. L., Plane, J. M. C., and Feng, W.: Dissociative Recombination of FeO+ with Electrons: Implications for Plasma Layers in the Ionosphere, J. Phys. Chem. A, 120, 1369–1376, https://doi.org/10.1021/acs.jpca.5b04947, 2016. a
Boris, J., Landsberg, A., Oran, E., and Gardner, J.: LCPFCT-A Flux-Corrected
Transport Algorithm for Solving Generalized Continuity Equations, Naval Research Lab Washington DC, NRL Memorandum Report, 93–7192, 1993. a
Cai, X., Yuan, T., and Eccles, J. V.: A Numerical Investigation on Tidal and Gravity Wave Contributions to the Summer Time Na Variations in the Midlatitude E Region, J. Geophys. Res.-Space, 122, 10577–10595, https://doi.org/10.1002/2016JA023764, 2017. a
Cai, X., Yuan, T., Eccles, J. V., Pedatella, N. M., Xi, X., Ban, C., and Liu, A. Z.: A Numerical Investigation on the Variation of Sodium Ion and Observed Thermospheric Sodium Layer at Cerro Pachón, Chile During Equinox, J. Geophys. Res.-Space, 124, 10395–10414, https://doi.org/10.1029/2018JA025927, 2019. a, b
Carrillo-Sánchez, J. D., Gómez-Martín, J. C., Bones, D. L., Nesvorný, D., Pokorný, P., Benna, M., Flynn, G. J., and Plane, J. M.: Cosmic dust fluxes in the atmospheres of Earth, Mars, and Venus, Icarus, 335, 113395, https://doi.org/10.1016/j.icarus.2019.113395, 2020. a
Carter, L. N. and Forbes, J. M.: Global transport and localized layering of metallic ions in the upper atmospherer, Ann. Geophys., 17, 190–209, https://doi.org/10.1007/s00585-999-0190-6, 1999. a, b
Chu, X. and Yu, Z.: Formation mechanisms of neutral Fe layers in the
thermosphere at Antarctica studied with a thermosphere-ionosphere Fe/Fe+ (TIFe) model, J. Geophys. Res.-Space, 122, 6812–6848, https://doi.org/10.1002/2016JA023773, 2017. a, b
Chu, X., Yu, Z., Gardner, C. S., Chen, C., and Fong, W.: Lidar observations of neutral Fe layers and fast gravity waves in the thermosphere (110–155 km) at McMurdo (77.8∘ S, 166.7∘ E), Antarctica, Geophys. Res. Lett., 38, L23807, https://doi.org/10.1029/2011GL050016, 2011. a, b
Chu, X., Nishimura, Y., Xu, Z., Yu, Z., Plane, J. M. C., Gardner, C. S., and Ogawa, Y.: First Simultaneous Lidar Observations of Thermosphere-Ionosphere Fe and Na (TIFe and TINa) Layers at McMurdo (77.84∘ S, 166.67∘ E), Antarctica With Concurrent Measurements of Aurora Activity, Enhanced Ionization Layers, and Converging Electric Field, Geophys. Res. Lett., 47, e2020GL090181, https://doi.org/10.1029/2020GL090181, 2020. a, b
Dou, X. K., Qiu, S. C., Xue, X. H., Chen, T. D., and Ning, B. Q.: Sporadic and thermospheric enhanced sodium layers observed by a lidar chain over China, J. Geophys. Res.-Space, 118, 6627–6643, https://doi.org/10.1002/JGRA.50579, 2013. a, b
Dymond, K. F., Wolfram, K. D., Budzien, S. A., Nicholas, A. C., McCoy, R. P., and Thomas, R. J.: Middle ultraviolet emission from ionized iron, Geophys. Res. Lett., 30, 1003, https://doi.org/10.1029/2002GL015060, 2003. a, b
Feng, W. H., Marsh, D. R., Chipperfield, M. P., Janches, D., Hoffner, J., Yi, F., and Plane, J. M. C.: A global atmospheric model of meteoric iron, J. Geophys. Res.-Atmos., 118, 9456–9474, 2013. a
Friedman, J. S., Chu, X., Brum, C. G. M., and Lu, X.: Observation of a thermospheric descending layer of neutral K over Arecibo, J. Atmos. Sol.-Terr. Phy., 104, 253–259, https://doi.org/10.1016/j.jastp.2013.03.002, 2013. a
Gao, Q., Chu, X., Xue, X., Dou, X., Chen, T., and Chen, J.: Lidar observations of thermospheric Na layers up to 170 km with a descending tidal phase at Lijiang (26.7∘ N, 100.0∘ E), China, J. Geophys. Res.-Space, 120, 9213–9220, https://doi.org/10.1002/2015JA021808, 2015. a
Huba, J. D., Krall, J., and Drob, D.: Global Ionospheric Metal Ion Transport With SAMI3, Geophys. Res. Lett., 46, 7937–7944, https://doi.org/10.1029/2019GL083583, 2019. a, b
Hurrell, J. W., Holland, M. M., Gent, P. R., Ghan, S., Kay, J. E., Kushner, P. J., Lamarque, J.-F., Large, W. G., Lawrence, D., Lindsay, K., Lipscomb, W. H., Long, M. C., Mahowald, N., Marsh, D. R., Neale, R. B., Rasch, P., Vavrus, S., Vertenstein, M., Bader, D., Collins, W. D., Hack, J. J., Kiehl, J., and Marshall, S.: The Community Earth System Model: A Framework for Collaborative Research, B. Am. Meteorol. Soc., 94, 1339–1360, https://doi.org/10.1175/BAMS-D-12-00121.1, 2013. a
Joiner, J. and Aikin, A. C.: Temporal and spatial variations in upper atmospheric Mg+, J. Geophys. Res.-Space, 101, 5239–5249, https://doi.org/10.1029/95JA03517, 1996. a
Kelley, M.: The Earth's Ionosphere: Plasma Physics and Electrodynamics, 2nd edn., Elsevier, Academic Press, London, UK, 2009. a
Kumar, S. and Hanson, W. B.: The morphology of metallic ions in the upper atmosphere, J. Geophys. Res., 85, 6783–6801, https://doi.org/10.1029/JA085iA12p06783, 1980. a
Langowski, M. P., von Savigny, C., Burrows, J. P., Feng, W., Plane, J. M. C., Marsh, D. R., Janches, D., Sinnhuber, M., Aikin, A. C., and Liebing, P.: Global investigation of the Mg atom and ion layers using SCIAMACHY/Envisat observations between 70 and 150 km altitude and WACCM-Mg model results, Atmos. Chem. Phys., 15, 273–295, https://doi.org/10.5194/acp-15-273-2015, 2015. a, b, c, d, e, f, g
Layzer, D.: Theory of Midlatitude Sporadic E, Radio Sci., 7, 385–395, https://doi.org/10.1029/RS007i003p00385, 1972. a
Liu, A. Z., Guo, Y., Vargas, F., and Swenson, G. R.: First measurement of horizontal wind and temperature in the lower thermosphere (105–140 km) with a Na Lidar at Andes Lidar Observatory, Geophys. Res. Lett., 43, 2374–2380, https://doi.org/10.1002/2016GL068461, 2016. a
Liu, H., Foster, B. T., Hagan, M. E., McInerney, J. M., Maute, A., Qian, L., Richmond, A. D., Roble, R. G., Solomon, S. C., Garcia, R. R., Kinnison, D., Marsh, D. R., Smith, A. K., Richter, J., Sassi, F., and Oberheide, J.: Thermosphere extension of the Whole Atmosphere Community Climate Model, J. Geophys. Res.-Space, 115, A12302, https://doi.org/10.1029/2010JA015586, 2010. a
Liu, H., Bardeen, C. G., Foster, B. T., Lauritzen, P., Liu, J., Lu, G., Marsh, D. R., Maute, A., McInerney, J. M., Pedatella, N. M., Qian, L., Richmond, A. D., Roble, R. G., Solomon, S. C., Vitt, F. M., and Wang, W.: Development and Validation of the Whole Atmosphere Community Climate Model With Thermosphere and Ionosphere Extension (WACCM-X 2.0), J. Adv. Model. Earth Sy., 10, 381–402, https://doi.org/10.1002/2017MS001232, 2018a. a, b, c
Liu, J., Liu, H., Wang, W., Burns, A. G., Wu, Q., Gan, Q., Solomon, S. C., Marsh, D. R., Qian, L., Lu, G., Pedatella, N. M., McInerney, J. M., Russell, J. M., and Schreiner, W. S.: First Results From the Ionospheric Extension of WACCM-X During the Deep Solar Minimum Year of 2008, J. Geophys. Res.-Space, 123, 1534–1553, https://doi.org/10.1002/2017JA025010, 2018b. a
Marsh, D. R., Janches, D., Feng, W. H., and Plane, J. M. C.: A global model of meteoric sodium, J. Geophys. Res.-Atmos., 118, 11442–11452, 2013a. a
Marsh, D. R., Mills, M. J., Kinnison, D. E., Lamarque, J. F., Calvo, N., and Polvani, L. M.: Climate Change from 1850 to 2005 Simulated in CESM1(WACCM), J. Climate, 26, 7372–7391, https://doi.org/10.1175/JCLI-D-12-00558.1, 2013b. a
Narcisi, R. S.: Processes associated with metal-ion layers in the E region of the ionosphere, Space Research, 8, 360–369, 1968. a
Neale, R. B., Richter, J., Park, S., Lauritzen, P. H., Vavrus, S. J., Rasch, P. J., and Zhang, M. H.: The Mean Climate of the Community Atmosphere Model (CAM4) in Forced SST and Fully Coupled Experiments, J. Climate, 26, 5150–5168, https://doi.org/10.1175/JCLI-D-12-00236.1, 2013. a
Pi, X. Q., Mannucci, A. J., Iijima, B. A., Wilson, B. D., Komjathy, A., Runge, T. F., and Akopian, V.: Assimilative Modeling of Ionospheric Disturbances with FORMOSAT-3/COSMIC and Ground-Based GPS Measurements, Terr. Atmos. Ocean. Sci., 20, 273–285, https://doi.org/10.3319/Tao.2008.01.04.01(F3c), 2009. a
Qiu, S. C., Tang, Y. H., Jia, M. J., Xue, X. H., Dou, X. K., Li, T., and Wang, Y. H.: A review of latitudinal characteristics of sporadic sodium layers, including new results from the Chinese Meridian Project, Earth-Sci. Rev., 162, 83–106, https://doi.org/10.1016/j.earscirev.2016.07.004, 2016. a
Schunk, R. W. and Nagy, A. F.: Simplified Transport Equations,
Cambridge Atmospheric and Space Science Series, Cambridge University Press, Cambridge, U.K., 104–147, https://doi.org/10.1017/CBO9780511551772.005, 2000. a
UCAR: CESM2 model, UCAR [code], available at: http://www.cesm.ucar.edu/models/cesm2/, last access: 8 October 2021. a
University of Science and Technology of China: Atmospheric Metal Data Simulated by WACCMX model repository, National Space Science Data Center [data set], https://doi.org/10.12176/01.60.00002-V01, 2021. a
Viehl, T. P., Plane, J. M. C., Feng, W., and Höffner, J.: The photolysis of FeOH and its effect on the bottomside of the mesospheric Fe layer, Geophys. Res. Lett., 43, 1373–1381, https://doi.org/10.1002/2015GL067241, 2016. a
Wang, J., Yang, Y., Cheng, X., Yang, G., Song, S., and Gong, S.: Double sodium layers observation over Beijing, China, Geophys. Res. Lett., 39, L15801, https://doi.org/10.1029/2012GL052134, 2012. a, b
Whalley, C. L., Martín, J. C. G., Wright, T. G., and Plane, J. M. C.: A kinetic study of Mg+ and Mg-containing ions reacting with O3, O2, N2, CO2, N2O and H2O: implications for magnesium ion chemistry in the upper atmosphere, Phys. Chem. Chem. Phys., 13, 6352–6364, https://doi.org/10.1039/C0CP02637A, 2011.
a
Wu, J., Feng, W., Liu, H.-L., Xue, X., Marsh, D. R., and Plane, J. M. C.: Simulation data of ‘Self-consistent Global Transport of Metallic Ions with WACCM-X’, V1, NSSDC Space Science Article Data Repository [data set], https://doi.org/10.12176/01.99.00212, 2021. a
Xue, X. H., Dou, X. K., Lei, J., Chen, J. S., Ding, Z. H., Li, T., Gao, Q., Tang, W. W., Cheng, X. W., and Wei, K.: Lower thermospheric-enhanced sodium layers observed at low latitude and possible formation: Case studies, J. Geophys. Res.-Space, 118, 2409–2418, https://doi.org/10.1002/JGRA.50200, 2013. a
Xun, Y., Yang, G., Wang, J., Du, L., Wang, Z., Jiao, J., Cheng, X., Li, F.,
and Zou, X.: The Comprehensive Study of Low Thermospheric Sodium Layers during
the 24th Solar Cycle, Atmosphere, 11, 284, https://doi.org/10.3390/atmos11030284, 2020. a, b
Yu, B., Xue, X., Scott, C. J., Wu, J., Yue, X., Feng, W., Chi, Y., Marsh, D. R., Liu, H., Dou, X., and Plane, J. M. C.: Interhemispheric transport of metallic ions within ionospheric sporadic E layers by the lower thermospheric meridional circulation, Atmos. Chem. Phys., 21, 4219–4230, https://doi.org/10.5194/acp-21-4219-2021, 2021. a
Yuan, T., Wang, J., Cai, X., Sojka, J., Rice, D., Oberheide, J., and Criddle, N.: Investigation of the seasonal and local time variations of the high-altitude sporadic Na layer (Nas) formation and the associated midlatitude descending E layer (Es) in lower E region, J. Geophys. Res.-Space, 119, 5985–5999, https://doi.org/10.1002/2014JA019942, 2014. a, b
Short summary
Metal layers occur in the MLT region (80–120 km) from the ablation of cosmic dust. The latest lidar observations show these metals can reach a height approaching 200 km, which is challenging to explain. We have developed the first global simulation incorporating the full life cycle of metal atoms and ions. The model results compare well with lidar and satellite observations of the seasonal and diurnal variation of the metals and demonstrate the importance of ion mass and ion-neutral coupling.
Metal layers occur in the MLT region (80–120 km) from the ablation of cosmic dust. The latest...
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