Последние статьи в Annales Geophysicae

TIMED Doppler Interferometer Measurements of Neutral Winds at the Mesosphere and Lower Thermosphere and Comparison to Meteor Radar Winds
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. Discuss., https//doi.org/10.5194/angeo-2024-13,2024
Preprint under review for ANGEO (discussion: open, 0 comments)
This study focuses on the 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 winds measurements and MR winds shows good agreement. A TIDI-MR seasonal comparison and the altitude-latitude dependence for winds is performed. TIDI reproduce the mean circulation well when compared with the MRs and might be useful as a lower boundary for general circulation models.

Long-term changes in the dependence of NmF2 on solar flux at Juliusruh
Maria Gloria Tan Jun Rios, Claudia Borries, Huixin Liu, and Jens Mielich
Ann. Geophys. Discuss., https//doi.org/10.5194/angeo-2024-11,2024
Preprint under review for ANGEO (discussion: open, 3 comments)
The study analyzes hourly NmF2 data from Juliusruh (1957 to 2023) and examines the response of NmF2 to solar flux by using three different solar EUV proxies for six solar cycles, including a separation of the ascending and descending phases. The response is better represented with a quadratic regression and F30 shows the highest correlation for describing NmF2 dependence over time. These results revealed a steady decrease in NmF2, influenced by the intensity of the solar activity index.

Ionospheric upwelling and the level of associated noise at solar minimum
Timothy Wemimo David, Chizurumoke Michael Michael, Darren Wright, Adetoro Temitope Talabi, and Abayomi Ekundayo Ajetunmobi
Ann. Geophys., 42, 349–354, https://doi.org/10.5194/angeo-42-349-2024, 2024
The Earth’s upper atmospheres are dominated by matter also known as plasma. These plasmas can flow from the lower region, the ionosphere, to the further-up region, the magnetosphere, which is described as upwelling. We analyse data for ionospheric upwelling over the solar minimum period. A main finding is that the noise or rejected data in the dataset were predominant around the local evening and in winter and minimum around local noon and in summer.

Sensitivity analysis of a Martian atmospheric column model with data from the Mars Science Laboratory
Joonas Leino, Ari-Matti Harri, Mark Paton, Jouni Polkko, Maria Hieta, and Hannu Savijärvi
Ann. Geophys., 42, 331–348, https://doi.org/10.5194/angeo-42-331-2024, 2024
The 1-D column model has been used extensively in studying the Martian atmosphere. In this study, we investigated the sensitivity of the column model to its initialization. The results of the model were compared with Curiosity rover measurements. The initial value of airborne dust and surface temperature had the greatest influence on the temperature prediction, while the initial atmospheric moisture content and the shape of the initial moisture profile modified the humidity prediction the most.

Multi-GNSS real-time tropospheric delay retrieval based on SSR products from different analysis centers
Wanqiang Yao, Haoran Huang, Xiongwei Ma, Qi Zhang, Yibin Yao, Xiaohu Lin, Qingzhi Zhao, and Yunzheng Huang
Ann. Geophys. Discuss., https//doi.org/10.5194/angeo-2024-8,2024
Preprint under review for ANGEO (discussion: final response, 4 comments)
There is limited discussion on the impact of SSR corrections based on different ACs on RT ZTD accuracy. In this study, RT-PPP based on multiple ACs is used to estimate the positioning performance and ZTD accuracy of SSR products based on different ACs. GNSS from 8 IGMAS stations is increased from 355 in 2023 to 14 in 2024. WHU-SSR has a higher accuracy of RT-PPP derived ZTD with an RMSE of 6.06 mm and a perfect availability with an integrity rate of 89 %.

Characteristic features of latitudinal manifestations of the 23–24 April 2023 geomagnetic storm
Leonid Chernogor
Ann. Geophys. Discuss., https//doi.org/10.5194/angeo-2024-9,2024
Revised manuscript under review for ANGEO (discussion: final response, 6 comments)
Ground-based magnetometer observations show that part of the near-Earth cross-tail current closed itself via the ionosphere, to which it was linked by the substorm current wedge, and manifested itself in the magnetograms acquired at high and equatorial latitude stations on the night side of the Earth. Observations suggest that the Bz interplanetary magnetic field component threshold for the formation of the substorm current wedge lies in the –(22–30) nT interval.

Low-frequency solar radio type II bursts and their association with space weather events during the ascending phase of solar cycle 25
Theogene Ndacyayisenga, Jean Uwamahoro, Jean Claude Uwamahoro, Daniel Izuikedinachi Okoh, Kantepalli Sasikumar Raja, Akeem Babatunde Rabiu, Christian Kwisanga, and Christian Monstein
Ann. Geophys., 42, 313–329, https://doi.org/10.5194/angeo-42-313-2024, 2024
This article reports the first observations of 32 type II bursts in cycle 25 from May 2021 to December 2022. The impacts of space weather on ionospheric total electron content (TEC) enhancement, as measured by the rate of change of TEC index (ROTI), are also studied. According to the current analysis, 19 of 32 type II bursts are connected with imminent space weather occurrences, such as radio blackouts and polar cap absorption events, indicating a high likelihood of space weather disturbance. 

Observations of ionospheric disturbances associated with the 2020 Beirut explosion by Defense Meteorological Satellite Program and ground-based ionosondes
Rezy Pradipta and Pei-Chen Lai
Ann. Geophys., 42, 301–312, https://doi.org/10.5194/angeo-42-301-2024, 2024
A large explosion released a significant amount of energy into the Earth's upper atmosphere in Beirut on 4 Aug 2020, generating traveling ionospheric disturbances (TIDs). These TIDs were observed in previous work using GPS total electron content measurements around Beirut. Here, we used measurements from the Defense Meteorological Satellite Program and ionosondes in the Mediterranean to show that the TIDs from the Beirut explosion were able to reach greater distances than previously reported.

On the relationship between the mesospheric sodium layer and the meteoric input function
Yanlin Li, Tai-Yin Huang, Julio Urbina, Fabio Vargas, and Wuhu Feng
Ann. Geophys., 42, 285–299, https://doi.org/10.5194/angeo-42-285-2024, 2024
This work combines lidar observation data and a new numerical sodium (Na) chemistry model, using data assimilation to study the relation between the mesospheric Na layer and the meteoric input function. Simulation captures the seasonal variability in the Na number density compared with lidar observations over the Colorado State University (CSU) lidar. The estimated global ablated meteoroid material inputs from Andes Lidar Observatory and CSU observations are 83 t d-1 and 53 t d-1, respectively.

Observations of traveling ionospheric disturbances driven by gravity waves from sources in the upper and lower atmosphere
Paul Prikryl, David R. Themens, Jaroslav Chum, Shibaji Chakraborty, Robert G. Gillies, and James M. Weygand
Ann. Geophys. Discuss., https//doi.org/10.5194/angeo-2024-6,2024
Preprint under review for ANGEO (discussion: open, 3 comments)
Travelling ionospheric disturbances are plasma density fluctuations usually driven by atmospheric gravity waves in the neutral atmosphere. The aim of this study is to attribute multi-instrument observations of travelling ionospheric disturbances to gravity waves generated in the upper atmosphere at high latitudes or gravity waves generated by tropospheric weather systems at mid latitudes.

Scale size estimation and flow pattern recognition around a magnetosheath jet
Adrian Pöppelwerth, Georg Glebe, Johannes Z. D. Mieth, Florian Koller, Tomas Karlsson, Zoltán Vörös, and Ferdinand Plaschke
Ann. Geophys., 42, 271–284, https://doi.org/10.5194/angeo-42-271-2024, 2024
In the magnetosheath, a near-Earth region of space, we observe increases in plasma velocity and density, so-called jets. As they propagate towards Earth, jets interact with the ambient plasma. We study this interaction with three spacecraft simultaneously to infer their sizes. While previous studies have investigated their size almost exclusively statistically, we demonstrate a new method of determining the sizes of individual jets.

Atmospheric odd nitrogen response to electron forcing from a 6D magnetospheric hybrid-kinetic simulation
Tuomas Häkkilä, Maxime Grandin, Markus Battarbee, Monika E. Szeląg, Markku Alho, Leo Kotipalo, Niilo Kalakoski, Pekka T. Verronen, and Minna Palmroth
Ann. Geophys. Discuss., https//doi.org/10.5194/angeo-2024-7,2024
Preprint under review for ANGEO (discussion: final response, 3 comments)
We study the atmospheric impact of auroral electron precipitation, by the novel combination of both magnetospheric and atmospheric modelling. We first simulate fluxes of auroral electrons, and then use these fluxes to model their atmospheric impact. We find an increase of up to 200 % in thermospheric odd nitrogen, and a corresponding decrease in stratospheric ozone of around 0.7 %. The produced auroral electron precipitation is realistic, and shows the potential for future studies.

On the importance of middle-atmosphere observations on ionospheric dynamics using WACCM-X and SAMI3
Fabrizio Sassi, Angeline G. Burrell, Sarah E. McDonald, Jennifer L. Tate, and John P. McCormack
Ann. Geophys., 42, 255–269, https://doi.org/10.5194/angeo-42-255-2024, 2024
This study shows how middle-atmospheric data (starting at 40 km) affect day-to-day ionospheric variability. We do this by using lower atmospheric measurements that include and exclude the middle atmosphere in a coupled ionosphere–thermosphere model. Comparing the two simulations reveals differences in two thermosphere–ionosphere coupling mechanisms. Additionally, comparison against observations showed that including the middle-atmospheric data improved the resulting ionosphere.

Influence of meteoric smoke particles on the incoherent scatter measured with EISCAT VHF
Tinna L. Gunnarsdottir, Ingrid Mann, Wuhu Feng, Devin R. Huyghebaert, Ingemar Haeggstroem, Yasunobu Ogawa, Norihito Saito, Satonori Nozawa, and Takuya D. Kawahara
Ann. Geophys., 42, 213–228, https://doi.org/10.5194/angeo-42-213-2024, 2024
Several tons of meteoric particles burn up in our atmosphere each day. This deposits a great deal of material that binds with other atmospheric particles and forms so-called meteoric smoke particles. These particles are assumed to influence radar measurements. Here, we have compared radar measurements with simulations of a radar spectrum with and without dust particles and found that dust influences the radar spectrum in the altitude range of 75–85 km.

Does high-latitude ionospheric electrodynamics exhibit hemispheric mirror symmetry?
Spencer Mark Hatch, Heikki Vanhamäki, Karl Magnus Laundal, Jone Peter Reistad, Johnathan K. Burchill, Levan Lomidze, David J. Knudsen, Michael Madelaire, and Habtamu Tesfaw
Ann. Geophys., 42, 229–253, https://doi.org/10.5194/angeo-42-229-2024, 2024
In studies of the Earth's ionosphere, a hot topic is how to estimate ionospheric conductivity. This is hard to do for a variety of reasons that mostly amount to a lack of measurements. In this study we use satellite measurements to estimate electromagnetic work and ionospheric conductances in both hemispheres. We identify where our model estimates are inconsistent with laws of physics, which partially solves a previous problem with unrealistic predictions of ionospheric conductances.

Impact ionization double peaks analyzed in high temporal resolution on Solar Orbiter
Samuel Kočiščák, Andreas Kvammen, Ingrid Mann, Nicole Meyer-Vernet, David Píša, Jan Souček, Audun Theodorsen, Jakub Vaverka, and Arnaud Zaslavsky
Ann. Geophys., 42, 191–212, https://doi.org/10.5194/angeo-42-191-2024, 2024
In situ observations are crucial for understanding interplanetary dust, yet not every spacecraft has a dedicated dust detector. Dust encounters happen at great speeds, leading to high energy density at impact, which leads to ionization and charge release, which is detected with electrical antennas.  Our work looks at how the transient charge plume interacts with Solar Orbiter spacecraft. Our findings are relevant for the design of future experiments and the understanding of present data.

Application of generalized aurora computed tomography to the EISCAT_3D project
Yoshimasa Tanaka, Yasunobu Ogawa, Akira Kadokura, Takehiko Aso, Björn Gustavsson, Urban Brändström, Tima Sergienko, Genta Ueno, and Satoko Saita
Ann. Geophys., 42, 179–190, https://doi.org/10.5194/angeo-42-179-2024, 2024
We present via simulation how useful monochromatic images taken by a multi-point imager network are for auroral research in the EISCAT_3D project. We apply the generalized-aurora computed tomography (G-ACT) to modeled multiple auroral images and ionospheric electron density data. It is demonstrated that G-ACT provides better reconstruction results than the normal ACT and can interpolate ionospheric electron density at a much higher spatial resolution than observed by the EISCAT_3D radar.

Permutation entropy and complexity analysis of large-scale solar wind structures and streams
Emilia K. J. Kilpua, Simon Good, Matti Ala-Lahti, Adnane Osmane, and Venla Koikkalainen
Ann. Geophys., 42, 163–177, https://doi.org/10.5194/angeo-42-163-2024, 2024
The solar wind is organised into slow and fast streams, interaction regions, and transient structures originating from solar eruptions. Their internal characteristics are not well understood. A more comprehensive understanding of such features can give insight itno physical processes governing their formation and evolution. Using tools from information theory, we find that the solar wind shows universal turbulent properties on smaller scales, while on larger scales, clear differences arise. 

Finding reconnection lines and flux rope axes via local coordinates in global ion-kinetic magnetospheric simulations
Markku Alho, Giulia Cozzani, Ivan Zaitsev, Fasil Tesema Kebede, Urs Ganse, Markus Battarbee, Maarja Bussov, Maxime Dubart, Sanni Hoilijoki, Leo Kotipalo, Konstantinos Papadakis, Yann Pfau-Kempf, Jonas Suni, Vertti Tarvus, Abiyot Workayehu, Hongyang Zhou, and Minna Palmroth
Ann. Geophys., 42, 145–161, https://doi.org/10.5194/angeo-42-145-2024, 2024
Magnetic reconnection is one of the main processes for energy conversion and plasma transport in space plasma physics, associated with plasma entry into the magnetosphere of Earth and Earth’s substorm cycle. Global modelling of these plasma processes enables us to understand the magnetospheric system in detail. However, finding sites of active reconnection from large simulation datasets can be challenging, and this paper develops tools to find magnetic topologies related to reconnection.