Articles | Volume 44, issue 2
https://doi.org/10.5194/angeo-44-1303-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/angeo-44-1303-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Regular paper
| 
10 Nov 2026
Regular paper |
| 10 Nov 2026
| 10 Nov 2026
Reevaluation of EISCAT plasma parameters during the May 2024 geomagnetic storm using O+ ratios from AMIE-driven SD-WACCM-X
Florian Günzkofer
CORRESPONDING AUTHOR
Institute for Solar-Terrestrial Physics, German Aerospace Center (DLR), Neustrelitz, Germany
Anders Tjulin
EISCAT AB, Kiruna, Sweden
Gang Lu
High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, USA
Hanli Liu
High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, USA
Gunter Stober
Institute of Applied Physics, Microwave Physics, University of Bern, Bern, Switzerland
Oeschger Center for Climate Change Research, Microwave Physics, University of Bern, Bern, Switzerland
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Florian Günzkofer, Gunter Stober, Johan Kero, David R. Themens, Anders Tjulin, Njål Gulbrandsen, Masaki Tsutsumi, and Claudia Borries
Ann. Geophys., 43, 331–348, https://doi.org/10.5194/angeo-43-331-2025, https://doi.org/10.5194/angeo-43-331-2025, 2025
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The Earth’s magnetic field is not closed at high latitudes. Electrically charged particles can penetrate the Earth’s atmosphere, deposit their energy, and heat the local atmosphere–ionosphere. This presumably causes an upwelling of the neutral atmosphere, which affects the atmosphere–ionosphere coupling. We apply a new analysis technique to infer the atmospheric density from incoherent scatter radar measurements. We identify signs of particle precipitation impact on the neutral atmosphere.
Florian Günzkofer, Gunter Stober, Dimitry Pokhotelov, Yasunobu Miyoshi, and Claudia Borries
Atmos. Meas. Tech., 16, 5897–5907, https://doi.org/10.5194/amt-16-5897-2023, https://doi.org/10.5194/amt-16-5897-2023, 2023
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Electric currents in the ionosphere can impact both satellite and ground-based infrastructure. These currents depend strongly on the collisions of ions and neutral particles. Measuring ion–neutral collisions is often only possible via certain assumptions. The direct measurement of ion–neutral collision frequencies is possible with multifrequency incoherent scatter radar measurements. This paper presents one analysis method of such measurements and discusses its advantages and disadvantages.
Florian Günzkofer, Dimitry Pokhotelov, Gunter Stober, Ingrid Mann, Sharon L. Vadas, Erich Becker, Anders Tjulin, Alexander Kozlovsky, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Evgenia Belova, Johan Kero, Nicholas J. Mitchell, and Claudia Borries
Ann. Geophys., 41, 409–428, https://doi.org/10.5194/angeo-41-409-2023, https://doi.org/10.5194/angeo-41-409-2023, 2023
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Gravity waves (GWs) are waves in Earth's atmosphere and can be observed as cloud ripples. Under certain conditions, these waves can propagate up into the ionosphere. Here, they can cause ripples in the ionosphere plasma, observable as oscillations of the plasma density. Therefore, GWs contribute to the ionospheric variability, making them relevant for space weather prediction. Additionally, the behavior of these waves allows us to draw conclusions about the atmosphere at these altitudes.
Loretta Pearl Poku, Gunter Stober, Witali Krochin, Alan Liu, Alexander Kozlovsky, Diego Janches, Jie Zeng, Wen Yi, Hanli Liu, Zishun Qiao, Kaoru Sato, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Johan Kero, and Nicholas Mitchell
Atmos. Meas. Tech., 19, 7039–7069, https://doi.org/10.5194/amt-19-7039-2026, https://doi.org/10.5194/amt-19-7039-2026, 2026
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Reliable vertical wind retrieval is essential for understanding atmospheric coupling and
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the mesosphere and lower thermosphere, improve physical consistency, and compare results with
current state-of-the-art models (VVP, 3DVAR+DIV, JAWARA, and SE-WACCM-X). Results
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dynamics. We present a novel Volume Velocity Processing method in spherical coordinates for
the mesosphere and lower thermosphere, improve physical consistency, and compare results with
current state-of-the-art models (VVP, 3DVAR+DIV, JAWARA, and SE-WACCM-X). Results
show reduced altitude-dependent biases from incomplete representation of the observation
geometry in mean horizontal and vertical winds.
Ales Kuchar, Matthias Stocker, Alistair Bell, Bruno Lehner, Jessica Kult-Herdin, Gabriel Chiodo, Timofei Sukhodolov, Eugene Rozanov, Gunter Stober, and Harald E. Rieder
Atmos. Chem. Phys., 26, 15479–15493, https://doi.org/10.5194/acp-26-15479-2026, https://doi.org/10.5194/acp-26-15479-2026, 2026
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We investigated why the Northern Hemisphere winter polar vortex became unusually strong in the winter of 2024/2025. Using satellite and reanalysis datasets, and model simulations, we found that extra water erupted high in the atmosphere by the 2022 Hunga Tonga eruption led to cooling of polar latitudes of the upper atmosphere, helping the winds aloft intensify. This link suggests such volcanic eruptions can shape winters in the upper atmosphere for several years.
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EGUsphere, https://doi.org/10.5194/egusphere-2026-5705, https://doi.org/10.5194/egusphere-2026-5705, 2026
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We examined how major wintertime disruptions of the Arctic atmosphere affect the downward transport of nitric oxide. Using satellite observations and a whole-atmosphere model, we found that large-scale waves repeatedly organize nitric oxide into distinct regions and that this transport differs between split and displaced polar vortices. The results improve understanding of how atmospheric dynamics control chemical transport between the upper atmosphere and stratosphere.
Bernd Funke, Michael Höpfner, Stefan Bender, Quentin Errera, Udo Grabowski, Alex Hoffmann, Han-Li Liu, Nick M. Pedatella, Piera Raspollini, Jörn Ungermann, and Björn-Martin Sinnhuber
EGUsphere, https://doi.org/10.5194/egusphere-2026-3881, https://doi.org/10.5194/egusphere-2026-3881, 2026
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We introduce two performance modeling tools, the Linear Performance Estimator (LPE) and the Fast L2 Simulator (FL2S), developed for CAIRT, a proposed ESA Earth Explorer mission. CAIRT aims to observe the middle atmosphere using an Imaging Fourier Transform Spectrometer. LPE quantifies spatial resolution and tomographic retrieval uncertainties, while FL2S generates synthetic data products that mimic the retrieval chain. Together, they demonstrate CAIRT's ability to meet scientific requirements.
Simone Brunamonti, Yann Poltera, Gonzague Romanens, Alex Weitnauer, Philipp Scheidegger, Adrianos Filinis, Alistair Bell, Giovanni Martucci, Frank Gunther Wienhold, Thomas Peter, Peter Oelsner, Ruud Dirksen, Alexander Haefele, Lukas Emmenegger, Gunter Stober, and Béla Tuzson
EGUsphere, https://doi.org/10.5194/egusphere-2026-4762, https://doi.org/10.5194/egusphere-2026-4762, 2026
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Accurate measurements of the concentration of water vapor in the upper atmosphere are essential for reliable climate predictions. We investigated the performance of a new lightweight (less than 4 kg) hygrometer, based on laser absorption spectroscopy, in a series of atmospheric test flights using weather balloons, reaching up to 35 km altitude. The results demonstrate the high accuracy and suitability of this technique for applications in long-term climate monitoring and atmospheric research.
Joseph Klemp, William Skamarock, Soudeh Kamali, Han-Li Liu, and Jihyeon Jang
EGUsphere, https://doi.org/10.5194/egusphere-2026-3568, https://doi.org/10.5194/egusphere-2026-3568, 2026
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In numerically simulating atmospheric phenomena that extend into the thermosphere, it is important to allow the atmosphere to expand/contract vertically in response the significant diabatic heating/cooling that occurs at these high altitudes. This paper examines the suitability of employing a new treatment of the upper boundary in the MPAS-A model that permits its vertical mobility in deep-atmosphere global applications.
Louis Mirallie, Eliane Maillard Barras, Caroline Jonas, Corinne Vigouroux, Roeland Van Malderen, Irina Petropavlovskikh, Sophie Godin-Beekmann, Thierry Leblanc, Wolfgang Steinbrecht, Antoine Vadès, Rolf Ruefenacht, Alexander Haefele, Gunter Stober, Peter Effertz, Julian Gröbner, Gerard Ancellet, María Cazorla, Petra Duff, Matthias M. Frey, Michael Gill, James W. Hannigan, Nicholas Jones, Rigel Kivi, Raphael Köhler, Bogumil Kois, Debra E. Kollonige, Emmanuel Mahieu, Glen McConville, Johan Mellqvist, Gary Morris, Isao Murata, Tomoo Nagahama, Gerald E. Nedoluha, Shin-Ya Ogino, Richard Querel, Ryan M. Stauffer, Wolfgang Stremme, Kimberly Strong, Ralf Sussmann, Anne M. Thompson, and Yana Virolainen
Atmos. Chem. Phys., 26, 10303–10330, https://doi.org/10.5194/acp-26-10303-2026, https://doi.org/10.5194/acp-26-10303-2026, 2026
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Witali Krochin, Axel Murk, and Gunter Stober
EGUsphere, https://doi.org/10.5194/egusphere-2026-2364, https://doi.org/10.5194/egusphere-2026-2364, 2026
This preprint is open for discussion and under review for Annales Geophysicae (ANGEO).
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Witali Krochin, Axel Murk, Andres Luder, and Gunter Stober
Atmos. Meas. Tech., 19, 2103–2123, https://doi.org/10.5194/amt-19-2103-2026, https://doi.org/10.5194/amt-19-2103-2026, 2026
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In this manuscript a new fully polarimetric radiometer for ground-based temperature sounding, TEMPERA-C (Campaign Temperature Radiometer), is presented. The advantages of the fully polarimetric approach are discussed, and a fully polarimetric calibration method is described in detail. The final measurements and the continuous series of temperature retrievals from the high altitude research station on the Jungfraujoch are also shown in this manuscript.
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Atmos. Meas. Tech., 19, 1783–1799, https://doi.org/10.5194/amt-19-1783-2026, https://doi.org/10.5194/amt-19-1783-2026, 2026
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Water vapor is an essential climate variable in the Earth's atmosphere and plays an important role in the radiative balance, serving as the most significant greenhouse gas in the upper troposphere. Hence, high-quality and continuous measurements are required. In this paper, we present the breadboard design of a newly developed radiometer, which will retrieve vertical profiles of middle atmospheric water vapor.
Chao Ban, Xin Fang, Wen Yi, Jie Zeng, Gunter Stober, Weilin Pan, Tao Li, and Xianghui Xue
Atmos. Meas. Tech., 19, 1697–1709, https://doi.org/10.5194/amt-19-1697-2026, https://doi.org/10.5194/amt-19-1697-2026, 2026
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This paper presents an intercomparison of zonal winds observed by a sodium fluorescence lidar and three types of meteor radars – a multistatic meteor radar, a conventional monostatic radar, and a forward remote receiver – located near Hefei, China. The multistatic meteor radar shows the best agreement with the lidar measurements, confirming the reliability of its wind retrievals in the mesosphere and lower thermosphere and highlighting its potential for future atmospheric dynamics studies.
Masaru Kogure, In-Sun Song, Huixin Liu, and Han-Li Liu
Atmos. Chem. Phys., 26, 665–680, https://doi.org/10.5194/acp-26-665-2026, https://doi.org/10.5194/acp-26-665-2026, 2026
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We investigate how rising CO₂ changes the migrating diurnal tide driven by solar heating and latent heat. Using a state-of-the-art model under the most extreme scenario in the Intergovernmental Panel on Climate Change report, we find that the tide strengthens between 20–70 km but weakens between 90–110 km. The increase likely reflects lower density and stronger tropical convection, whereas the decrease is consistent with enhanced diffusion.
Stelios Tourgaidis, Dimitris Baloukidis, Panagiotis Pirnaris, Theodoros Sarris, Aaron Ridley, and Gang Lu
Ann. Geophys., 43, 881–899, https://doi.org/10.5194/angeo-43-881-2025, https://doi.org/10.5194/angeo-43-881-2025, 2025
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During geomagnetic storms, Joule heating is a major heating source of the upper atmosphere that is not well estimated, due to a lack of measurements. This leads to uncertainties in orbital calculations. We present simulations with commonly used physics-based models and empirical models that provide measurements of Joule heating. The results show great discrepancies, pointing to the need for measurements in the Earth's Lower Thermosphere-Ionosphere at altitudes where Joule heating maximizes.
Miriam Sinnhuber, Christina Arras, Stefan Bender, Bernd Funke, Hanli Liu, Daniel R. Marsh, Thomas Reddmann, Eugene Rozanov, Timofei Sukhodolov, Monika E. Szelag, and Jan Maik Wissing
Atmos. Chem. Phys., 25, 14719–14734, https://doi.org/10.5194/acp-25-14719-2025, https://doi.org/10.5194/acp-25-14719-2025, 2025
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Nitric oxide in the upper atmosphere varies with solar activity. Observations show that this starts a chain of processes affecting the ozone layer and climate system. This is often underestimated in models. We compare five models which show large differences in simulated NO. Analysis of these discrepancies identify two processes which interact with each other: the balance between atomic and molecular oxygen in the thermosphere, and a poleward - downward transport in the winter thermosphere.
Guochun Shi, Hanli Liu, Masaki Tsutsumi, Njål Gulbrandsen, Alexander Kozlovsky, Dimitry Pokhotelov, Mark Lester, Christoph Jacobi, Kun Wu, and Gunter Stober
Atmos. Chem. Phys., 25, 9403–9430, https://doi.org/10.5194/acp-25-9403-2025, https://doi.org/10.5194/acp-25-9403-2025, 2025
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Concerns about climate change are growing due to its widespread impacts, including rising temperatures, extreme weather events, and disruptions to ecosystems. To address these challenges, urgent global action is needed to monitor the distribution of trace gases and understand their effects on the atmosphere.
Ales Kuchar, Gunter Stober, Dimitry Pokhotelov, Huixin Liu, Han-Li Liu, Manfred Ern, Damian Murphy, Diego Janches, Tracy Moffat-Griffin, Nicholas Mitchell, and Christoph Jacobi
EGUsphere, https://doi.org/10.5194/egusphere-2025-2827, https://doi.org/10.5194/egusphere-2025-2827, 2025
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We studied how the healing of the Antarctic ozone layer is affecting winds high above the South Pole. Using ground-based radar, satellite data, and computer models, we found that winds in the upper atmosphere have become stronger over the past two decades. These changes appear to be linked to shifts in the lower atmosphere caused by ozone recovery. Our results show that human efforts to repair the ozone layer are also influencing climate patterns far above Earth’s surface.
Arthur Gauthier, Claudia Borries, Alexander Kozlovsky, Diego Janches, Peter Brown, Denis Vida, Christoph Jacobi, Damian Murphy, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Johan Kero, Nicholas Mitchell, Tracy Moffat-Griffin, and Gunter Stober
Ann. Geophys., 43, 427–440, https://doi.org/10.5194/angeo-43-427-2025, https://doi.org/10.5194/angeo-43-427-2025, 2025
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This study focuses on a TIMED Doppler Interferometer (TIDI)–meteor radar (MR) comparison of zonal and meridional winds and their dependence on local time and latitude. The correlation calculation between TIDI wind measurements and MR winds shows good agreement. A TIDI–MR seasonal comparison and analysis of the altitude–latitude dependence for winds are performed. TIDI reproduces the mean circulation well when compared with MRs and may be a useful lower boundary for general circulation models.
Florian Günzkofer, Gunter Stober, Johan Kero, David R. Themens, Anders Tjulin, Njål Gulbrandsen, Masaki Tsutsumi, and Claudia Borries
Ann. Geophys., 43, 331–348, https://doi.org/10.5194/angeo-43-331-2025, https://doi.org/10.5194/angeo-43-331-2025, 2025
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The Earth’s magnetic field is not closed at high latitudes. Electrically charged particles can penetrate the Earth’s atmosphere, deposit their energy, and heat the local atmosphere–ionosphere. This presumably causes an upwelling of the neutral atmosphere, which affects the atmosphere–ionosphere coupling. We apply a new analysis technique to infer the atmospheric density from incoherent scatter radar measurements. We identify signs of particle precipitation impact on the neutral atmosphere.
Alistair Bell, Axel Murk, and Gunter Stober
EGUsphere, https://doi.org/10.5194/egusphere-2025-1396, https://doi.org/10.5194/egusphere-2025-1396, 2025
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Increases in middle atmospheric water vapour from the 2022 Hunga eruption have been measured worldwide. This study uses remote sensing measurements at two latitudes and accurate radiative transfer modeling to show significant long-wave heating effects. Though minimal at the surface, the water vapour enhancement can alter middle-atmospheric dynamics, potentially affecting ozone chemistry and weather patterns.
Zishun Qiao, Alan Z. Liu, Gunter Stober, Javier Fuentes, Fabio Vargas, Christian L. Adami, and Iain M. Reid
Atmos. Meas. Tech., 18, 1091–1104, https://doi.org/10.5194/amt-18-1091-2025, https://doi.org/10.5194/amt-18-1091-2025, 2025
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This paper describes the installation of the Chilean Observation Network De Meteor Radars (CONDOR) and its initial results. The routine winds are point-to-point comparable to the co-located lidar winds. The retrievals of spatially resolved horizontal wind fields and vertical winds are also facilitated, benefiting from the extensive meteor detections. The successful deployment and maintenance of CONDOR provide 24/7 and state-of-the-art wind measurements to the research community.
Alistair Bell, Eric Sauvageat, Gunter Stober, Klemens Hocke, and Axel Murk
Atmos. Meas. Tech., 18, 555–567, https://doi.org/10.5194/amt-18-555-2025, https://doi.org/10.5194/amt-18-555-2025, 2025
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Hardware and software developments have been made on a 22 GHz microwave radiometer for the measurement of middle-atmospheric water vapour near Bern, Switzerland. Previous measurements dating back to 2010 have been re-calibrated and an improved optimal estimation retrieval performed on these measurements, giving a 13-year dataset. Measurements made with new and improved instrumental hardware are used to correct previous measurements, which show better agreement than the non-corrected dataset.
Guochun Shi, Witali Krochin, Eric Sauvageat, and Gunter Stober
Atmos. Chem. Phys., 24, 10187–10207, https://doi.org/10.5194/acp-24-10187-2024, https://doi.org/10.5194/acp-24-10187-2024, 2024
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Here we investigated ozone anomalies over polar regions during sudden stratospheric and final stratospheric warming with ground-based microwave radiometers at polar latitudes compared with reanalysis and satellite data. The underlying dynamical and chemical mechanisms are responsible for the observed ozone anomalies in both events. Our research sheds light on these processes, emphasizing the need for a deeper understanding of these processes for more accurate climate modeling and forecasting.
Witali Krochin, Axel Murk, and Gunter Stober
Atmos. Meas. Tech., 17, 5015–5028, https://doi.org/10.5194/amt-17-5015-2024, https://doi.org/10.5194/amt-17-5015-2024, 2024
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Atmospheric tides are global-scale oscillations with periods of a fraction of a day. Their observation in the middle atmosphere is challenging and rare, as it requires continuous measurements with a high temporal resolution. In this paper, temperature time series of a ground-based microwave radiometer were analyzed with a spectral filter to derive thermal tide amplitudes and phases in an altitude range of 25–50 km at the geographical locations of Payerne and Bern (Switzerland).
Qinzeng Li, Jiyao Xu, Aditya Riadi Gusman, Hanli Liu, Wei Yuan, Weijun Liu, Yajun Zhu, and Xiao Liu
Atmos. Chem. Phys., 24, 8343–8361, https://doi.org/10.5194/acp-24-8343-2024, https://doi.org/10.5194/acp-24-8343-2024, 2024
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The 2022 Hunga Tonga–Hunga Ha’apai (HTHH) volcanic eruption not only triggered broad-spectrum atmospheric waves but also generated unusual tsunamis which can generate atmospheric gravity waves (AGWs). Multiple strong atmospheric waves were observed in the far-field area of the 2022 HTHH volcano eruption in the upper atmosphere by a ground-based airglow imager network. AGWs caused by tsunamis can propagate to the mesopause region; there is a good match between atmospheric waves and tsunamis.
Gunter Stober, Sharon L. Vadas, Erich Becker, Alan Liu, Alexander Kozlovsky, Diego Janches, Zishun Qiao, Witali Krochin, Guochun Shi, Wen Yi, Jie Zeng, Peter Brown, Denis Vida, Neil Hindley, Christoph Jacobi, Damian Murphy, Ricardo Buriti, Vania Andrioli, Paulo Batista, John Marino, Scott Palo, Denise Thorsen, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Kathrin Baumgarten, Johan Kero, Evgenia Belova, Nicholas Mitchell, Tracy Moffat-Griffin, and Na Li
Atmos. Chem. Phys., 24, 4851–4873, https://doi.org/10.5194/acp-24-4851-2024, https://doi.org/10.5194/acp-24-4851-2024, 2024
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On 15 January 2022, the Hunga Tonga-Hunga Ha‘apai volcano exploded in a vigorous eruption, causing many atmospheric phenomena reaching from the surface up to space. In this study, we investigate how the mesospheric winds were affected by the volcanogenic gravity waves and estimated their propagation direction and speed. The interplay between model and observations permits us to gain new insights into the vertical coupling through atmospheric gravity waves.
Florian Günzkofer, Gunter Stober, Dimitry Pokhotelov, Yasunobu Miyoshi, and Claudia Borries
Atmos. Meas. Tech., 16, 5897–5907, https://doi.org/10.5194/amt-16-5897-2023, https://doi.org/10.5194/amt-16-5897-2023, 2023
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Electric currents in the ionosphere can impact both satellite and ground-based infrastructure. These currents depend strongly on the collisions of ions and neutral particles. Measuring ion–neutral collisions is often only possible via certain assumptions. The direct measurement of ion–neutral collision frequencies is possible with multifrequency incoherent scatter radar measurements. This paper presents one analysis method of such measurements and discusses its advantages and disadvantages.
Florian Günzkofer, Dimitry Pokhotelov, Gunter Stober, Ingrid Mann, Sharon L. Vadas, Erich Becker, Anders Tjulin, Alexander Kozlovsky, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Evgenia Belova, Johan Kero, Nicholas J. Mitchell, and Claudia Borries
Ann. Geophys., 41, 409–428, https://doi.org/10.5194/angeo-41-409-2023, https://doi.org/10.5194/angeo-41-409-2023, 2023
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Gravity waves (GWs) are waves in Earth's atmosphere and can be observed as cloud ripples. Under certain conditions, these waves can propagate up into the ionosphere. Here, they can cause ripples in the ionosphere plasma, observable as oscillations of the plasma density. Therefore, GWs contribute to the ionospheric variability, making them relevant for space weather prediction. Additionally, the behavior of these waves allows us to draw conclusions about the atmosphere at these altitudes.
Guochun Shi, Witali Krochin, Eric Sauvageat, and Gunter Stober
Atmos. Chem. Phys., 23, 9137–9159, https://doi.org/10.5194/acp-23-9137-2023, https://doi.org/10.5194/acp-23-9137-2023, 2023
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We present the interannual and climatological behavior of ozone and water vapor from microwave radiometers in the Arctic.
By defining a virtual conjugate latitude station in the Southern Hemisphere, we investigate altitude-dependent interhemispheric differences and estimate the ascent and descent rates of water vapor in both hemispheres. Ozone and water vapor measurements will create a deeper understanding of the evolution of middle atmospheric ozone and water vapor.
Gunter Stober, Alan Liu, Alexander Kozlovsky, Zishun Qiao, Witali Krochin, Guochun Shi, Johan Kero, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Kathrin Baumgarten, Evgenia Belova, and Nicholas Mitchell
Ann. Geophys., 41, 197–208, https://doi.org/10.5194/angeo-41-197-2023, https://doi.org/10.5194/angeo-41-197-2023, 2023
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The Hunga Tonga–Hunga Ha‘apai volcanic eruption was one of the most vigorous volcanic explosions in the last centuries. The eruption launched many atmospheric waves traveling around the Earth. In this study, we identify these volcanic waves at the edge of space in the mesosphere/lower-thermosphere, leveraging wind observations conducted with multi-static meteor radars in northern Europe and with the Chilean Observation Network De Meteor Radars (CONDOR).
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.
Gunter Stober, Alan Liu, Alexander Kozlovsky, Zishun Qiao, Ales Kuchar, Christoph Jacobi, Chris Meek, Diego Janches, Guiping Liu, Masaki Tsutsumi, Njål Gulbrandsen, Satonori Nozawa, Mark Lester, Evgenia Belova, Johan Kero, and Nicholas Mitchell
Atmos. Meas. Tech., 15, 5769–5792, https://doi.org/10.5194/amt-15-5769-2022, https://doi.org/10.5194/amt-15-5769-2022, 2022
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Precise and accurate measurements of vertical winds at the mesosphere and lower thermosphere are rare. Although meteor radars have been used for decades to observe horizontal winds, their ability to derive reliable vertical wind measurements was always questioned. In this article, we provide mathematical concepts to retrieve mathematically and physically consistent solutions, which are compared to the state-of-the-art non-hydrostatic model UA-ICON.
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.
Witali Krochin, Francisco Navas-Guzmán, David Kuhl, Axel Murk, and Gunter Stober
Atmos. Meas. Tech., 15, 2231–2249, https://doi.org/10.5194/amt-15-2231-2022, https://doi.org/10.5194/amt-15-2231-2022, 2022
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This study leverages atmospheric temperature measurements performed with a ground-based radiometer making use of data that was collected during a 4-year observational campaign applying a new retrieval algorithm that improves the maximal altitude range from 45 to 55 km. The measurements are validated against two independent data sets, MERRA2 reanalysis data and the meteorological analysis of NAVGEM-HA.
Sumanta Sarkhel, Gunter Stober, Jorge L. Chau, Steven M. Smith, Christoph Jacobi, Subarna Mondal, Martin G. Mlynczak, and James M. Russell III
Ann. Geophys., 40, 179–190, https://doi.org/10.5194/angeo-40-179-2022, https://doi.org/10.5194/angeo-40-179-2022, 2022
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A rare gravity wave event was observed on the night of 25 April 2017 over northern Germany. An all-sky airglow imager recorded an upward-propagating wave at different altitudes in mesosphere with a prominent wave front above 91 km and faintly observed below. Based on wind and satellite-borne temperature profiles close to the event location, we have found the presence of a leaky thermal duct layer in 85–91 km. The appearance of this duct layer caused the wave amplitudes to diminish below 91 km.
Christoph Jacobi, Friederike Lilienthal, Dmitry Korotyshkin, Evgeny Merzlyakov, and Gunter Stober
Adv. Radio Sci., 19, 185–193, https://doi.org/10.5194/ars-19-185-2021, https://doi.org/10.5194/ars-19-185-2021, 2021
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We compare winds and tidal amplitudes in the upper mesosphere/lower thermosphere region for cases with disturbed and undisturbed geomagnetic conditions. The zonal winds in both the mesosphere and lower thermosphere tend to be weaker during disturbed conditions. The summer equatorward meridional wind jet is weaker for disturbed geomagnetic conditions. The effect of geomagnetic variability on tidal amplitudes, except for the semidiurnal tide, is relatively small.
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Short summary
Incoherent scatter radars (ISRs) are an important measurement tool for space weather research. However, ISR measurements require previous knowledge of the state of the ionosphere, especially the ratio of atomic oxygen ions (O+) to electrons. We present ISR measurements during the May 2024 "Mothers' Day Storm" and apply data assimilation-based O+ ratios, which should result in more accurate ISR measurements. The advantages and disadvantages of our method are compared to those of other approaches.
Incoherent scatter radars (ISRs) are an important measurement tool for space weather research....
