04 Sep 2018
| 04 Sep 2018
Ionospheric response to solar EUV variations: Preliminary results
Rajesh Vaishnav
CORRESPONDING AUTHOR
Leipzig Institute for Meteorology, Universität Leipzig,
Stephanstr. 3, 04103 Leipzig, Germany
Christoph Jacobi
Leipzig Institute for Meteorology, Universität Leipzig,
Stephanstr. 3, 04103 Leipzig, Germany
Jens Berdermann
German Aerospace Center, Kalkhorstweg 53, 17235 Neustrelitz, Germany
Erik Schmölter
German Aerospace Center, Kalkhorstweg 53, 17235 Neustrelitz, Germany
Mihail Codrescu
Space Weather Prediction Centre, National Oceanic and Atmospheric
Administration, Boulder, Colorado, USA
Related authors
Rajesh Vaishnav, Christoph Jacobi, Jens Berdermann, Mihail Codrescu, and Erik Schmölter
Ann. Geophys., 39, 641–655, https://doi.org/10.5194/angeo-39-641-2021, https://doi.org/10.5194/angeo-39-641-2021, 2021
Short summary
Short summary
We investigate the role of eddy diffusion in the delayed ionospheric response against solar flux changes in the solar rotation period using the CTIPe model. The study confirms that eddy diffusion is an important factor affecting the delay of the total electron content. An increase in eddy diffusion leads to faster transport processes and an increased loss rate, resulting in a decrease in the ionospheric delay.
Rajesh Vaishnav, Erik Schmölter, Christoph Jacobi, Jens Berdermann, and Mihail Codrescu
Ann. Geophys., 39, 341–355, https://doi.org/10.5194/angeo-39-341-2021, https://doi.org/10.5194/angeo-39-341-2021, 2021
Short summary
Short summary
We investigate the delayed ionospheric response using the observed and CTIPe-model-simulated TEC against the solar EUV flux. The ionospheric delay estimated using model-simulated TEC is in good agreement with the delay estimated for observed TEC. The study confirms the model's capabilities to reproduce the delayed ionospheric response against the solar EUV flux. Results also indicate that the average delay is higher in the Northern Hemisphere as compared to the Southern Hemisphere.
Rajesh Vaishnav, Christoph Jacobi, and Jens Berdermann
Ann. Geophys., 37, 1141–1159, https://doi.org/10.5194/angeo-37-1141-2019, https://doi.org/10.5194/angeo-37-1141-2019, 2019
Short summary
Short summary
We investigate the ionospheric response to the temporal and spatial dynamics of the solar activity using total electron content (TEC) maps and multiple solar proxies. The maximum correlation at a 16–32-d timescale is observed between the He-II, Mg-II, and F30 with respect to global mean TEC, with an effective time delay of about 1 d. The most suitable proxy to represent the solar activity at the timescales of 16–32 d and 32–64 d is He-II.
Erik Schmölter, Jens Berdermann, Norbert Jakowski, Christoph Jacobi, and Rajesh Vaishnav
Adv. Radio Sci., 16, 149–155, https://doi.org/10.5194/ars-16-149-2018, https://doi.org/10.5194/ars-16-149-2018, 2018
Short summary
Short summary
Physical and chemical processes in the ionosphere are driven by complex interactions with the solar radiation. The ionospheric plasma is in particular sensitive to solar variations with a time delay between one and two days.
Here we present preliminary results of the ionospheric delay based on a comprehensive and reliable database consisting of GNSS TEC Maps and EUV spectral flux data.
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
Short summary
Short summary
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.
Sina Mehrdad, Sajedeh Marjani, Dörthe Handorf, and Christoph Jacobi
EGUsphere, https://doi.org/10.5194/egusphere-2025-3005, https://doi.org/10.5194/egusphere-2025-3005, 2025
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
Wind flowing over mountains creates wave-like patterns aloft that can influence the atmosphere higher up in the stratosphere and mesosphere. In this study, we intensified these waves over specific regions like the Himalayas and Rocky Mountains and examined the resulting climate effects. We found that this can shift global wind patterns and even impact extreme events near the poles, showing how small regional changes in stratospheric wind patterns can influence the broader climate system.
J. Federico Conte, Jorge L. Chau, Toralf Renkwitz, Ralph Latteck, Masaki Tsutsumi, Christoph Jacobi, Njål Gulbrandsen, and Satonori Nozawa
EGUsphere, https://doi.org/10.5194/egusphere-2025-1996, https://doi.org/10.5194/egusphere-2025-1996, 2025
Short summary
Short summary
Analysis of 10 years of continuous measurements provided MMARIA/SIMONe Norway and MMARIA/SIMONe Germany reveals that the divergent and vortical motions in the mesosphere and lower thermosphere exchange the dominant role depending on the height and the time of the year. At summer mesopause altitudes over middle latitudes, the horizontal divergence and the relative vorticity contribute approximately the same, indicating an energetic balance between mesoscale divergent and vortical motions.
Christoph Jacobi, Khalil Karami, Ales Kuchar, Manfred Ern, Toralf Renkwitz, Ralph Latteck, and Jorge L. Chau
Adv. Radio Sci., 23, 21–31, https://doi.org/10.5194/ars-23-21-2025, https://doi.org/10.5194/ars-23-21-2025, 2025
Short summary
Short summary
Half-hourly mean winds have been obtained using ground-based low-frequency and very high frequency radio observations of the mesopause region at Collm, Germany, since 1984. Long-term changes of wind variances, which are proxies for short-period atmospheric gravity waves, have been analysed. Gravity wave amplitudes increase with time in winter, but mainly decrease in summer. The trends are consistent with mean wind changes according to wave theory.
Sina Mehrdad, Dörthe Handorf, Ines Höschel, Khalil Karami, Johannes Quaas, Sudhakar Dipu, and Christoph Jacobi
Weather Clim. Dynam., 5, 1223–1268, https://doi.org/10.5194/wcd-5-1223-2024, https://doi.org/10.5194/wcd-5-1223-2024, 2024
Short summary
Short summary
This study introduces a novel deep learning (DL) approach to analyze how regional radiative forcing in Europe impacts the Arctic climate. By integrating atmospheric poleward energy transport with DL-based clustering of atmospheric patterns and attributing anomalies to specific clusters, our method reveals crucial, nuanced interactions within the climate system, enhancing our understanding of intricate climate dynamics.
Ales Kuchar, Maurice Öhlert, Roland Eichinger, and Christoph Jacobi
Weather Clim. Dynam., 5, 895–912, https://doi.org/10.5194/wcd-5-895-2024, https://doi.org/10.5194/wcd-5-895-2024, 2024
Short summary
Short summary
Exploring the polar vortex's impact on climate, the study evaluates model simulations against the ERA5 reanalysis data. Revelations about model discrepancies in simulating disruptive stratospheric warmings and vortex behavior highlight the need for refined model simulations of past climate. By enhancing our understanding of these dynamics, the research contributes to more reliable climate projections of the polar vortex with the impact on surface climate.
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
Short summary
Short summary
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.
Christoph Jacobi, Ales Kuchar, Toralf Renkwitz, and Juliana Jaen
Adv. Radio Sci., 21, 111–121, https://doi.org/10.5194/ars-21-111-2023, https://doi.org/10.5194/ars-21-111-2023, 2023
Short summary
Short summary
Middle atmosphere long-term changes show the signature of climate change. We analyse 43 years of mesopause region horizontal winds obtained at two sites in Germany. We observe mainly positive trends of the zonal prevailing wind throughout the year, while the meridional winds tend to decrease in magnitude in both summer and winter. Furthermore, there is a change in long-term trends around the late 1990s, which is most clearly visible in summer winds.
Juliana Jaen, Toralf Renkwitz, Huixin Liu, Christoph Jacobi, Robin Wing, Aleš Kuchař, Masaki Tsutsumi, Njål Gulbrandsen, and Jorge L. Chau
Atmos. Chem. Phys., 23, 14871–14887, https://doi.org/10.5194/acp-23-14871-2023, https://doi.org/10.5194/acp-23-14871-2023, 2023
Short summary
Short summary
Investigation of winds is important to understand atmospheric dynamics. In the summer mesosphere and lower thermosphere, there are three main wind flows: the mesospheric westward, the mesopause southward (equatorward), and the lower-thermospheric eastward wind. Combining almost 2 decades of measurements from different radars, we study the trend, their interannual oscillations, and the effects of the geomagnetic activity over these wind maxima.
Olivia Linke, Johannes Quaas, Finja Baumer, Sebastian Becker, Jan Chylik, Sandro Dahlke, André Ehrlich, Dörthe Handorf, Christoph Jacobi, Heike Kalesse-Los, Luca Lelli, Sina Mehrdad, Roel A. J. Neggers, Johannes Riebold, Pablo Saavedra Garfias, Niklas Schnierstein, Matthew D. Shupe, Chris Smith, Gunnar Spreen, Baptiste Verneuil, Kameswara S. Vinjamuri, Marco Vountas, and Manfred Wendisch
Atmos. Chem. Phys., 23, 9963–9992, https://doi.org/10.5194/acp-23-9963-2023, https://doi.org/10.5194/acp-23-9963-2023, 2023
Short summary
Short summary
Lapse rate feedback (LRF) is a major driver of the Arctic amplification (AA) of climate change. It arises because the warming is stronger at the surface than aloft. Several processes can affect the LRF in the Arctic, such as the omnipresent temperature inversion. Here, we compare multimodel climate simulations to Arctic-based observations from a large research consortium to broaden our understanding of these processes, find synergy among them, and constrain the Arctic LRF and AA.
Khalil Karami, Rolando Garcia, Christoph Jacobi, Jadwiga H. Richter, and Simone Tilmes
Atmos. Chem. Phys., 23, 3799–3818, https://doi.org/10.5194/acp-23-3799-2023, https://doi.org/10.5194/acp-23-3799-2023, 2023
Short summary
Short summary
Alongside mitigation and adaptation efforts, stratospheric aerosol intervention (SAI) is increasingly considered a third pillar to combat dangerous climate change. We investigate the teleconnection between the quasi-biennial oscillation in the equatorial stratosphere and the Arctic stratospheric polar vortex under a warmer climate and an SAI scenario. We show that the Holton–Tan relationship weakens under both scenarios and discuss the physical mechanisms responsible for such changes.
Christoph Jacobi, Kanykei Kandieva, and Christina Arras
Adv. Radio Sci., 20, 85–92, https://doi.org/10.5194/ars-20-85-2023, https://doi.org/10.5194/ars-20-85-2023, 2023
Short summary
Short summary
Sporadic E (Es) layers are thin regions of accumulated ions in the lower ionosphere. They can be observed by disturbances of GNSS links between low-Earth orbiting satellites and GNSS satellites. Es layers are influenced by neutral atmospheric tides and show the coupling between the neutral atmosphere and the ionosphere. Here we analyse migrating (sun-synchronous) and non-migrating tidal components in Es. The main signatures are migrating Es, but nonmigrating components are found as well.
Gerhard Georg Bruno Schmidtke, Raimund Brunner, and Christoph Jacobi
EGUsphere, https://doi.org/10.5194/egusphere-2023-139, https://doi.org/10.5194/egusphere-2023-139, 2023
Preprint withdrawn
Short summary
Short summary
The instrument records annual changes in Spectral Outgoing Radiation from 200–1100 nm, with 60 photomultiplier tubes simultaneously providing spectrometer and photometer data. Using Total Solar Irradiance data with a stability of 0.01 Wm-2 per year to recalibrate the established instruments, stable data of ~0.1 Wm-2 over a solar cycle period is expected. Determination of the changes in the global green Earth coverage and mapping will also assess the impact of climate engineering actions.
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
Short summary
Short summary
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.
Ales Kuchar, Petr Sacha, Roland Eichinger, Christoph Jacobi, Petr Pisoft, and Harald Rieder
EGUsphere, https://doi.org/10.5194/egusphere-2022-474, https://doi.org/10.5194/egusphere-2022-474, 2022
Preprint archived
Short summary
Short summary
We focus on the impact of small-scale orographic gravity waves (OGWs) above the Himalayas. The interaction of GWs with the large-scale circulation in the stratosphere is not still well understood and can have implications on climate projections. We use a chemistry-climate model to show that these strong OGW events are associated with anomalously increased upward planetary-scale waves and in turn affect the circumpolar circulation and have the potential to alter ozone variability as well.
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
Short summary
Short summary
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.
Juliana Jaen, Toralf Renkwitz, Jorge L. Chau, Maosheng He, Peter Hoffmann, Yosuke Yamazaki, Christoph Jacobi, Masaki Tsutsumi, Vivien Matthias, and Chris Hall
Ann. Geophys., 40, 23–35, https://doi.org/10.5194/angeo-40-23-2022, https://doi.org/10.5194/angeo-40-23-2022, 2022
Short summary
Short summary
To study long-term trends in the mesosphere and lower thermosphere (70–100 km), we established two summer length definitions and analyzed the variability over the years (2004–2020). After the analysis, we found significant trends in the summer beginning of one definition. Furthermore, we were able to extend one of the time series up to 31 years and obtained evidence of non-uniform trends and periodicities similar to those known for the quasi-biennial oscillation and El Niño–Southern Oscillation.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Rajesh Vaishnav, Christoph Jacobi, Jens Berdermann, Mihail Codrescu, and Erik Schmölter
Ann. Geophys., 39, 641–655, https://doi.org/10.5194/angeo-39-641-2021, https://doi.org/10.5194/angeo-39-641-2021, 2021
Short summary
Short summary
We investigate the role of eddy diffusion in the delayed ionospheric response against solar flux changes in the solar rotation period using the CTIPe model. The study confirms that eddy diffusion is an important factor affecting the delay of the total electron content. An increase in eddy diffusion leads to faster transport processes and an increased loss rate, resulting in a decrease in the ionospheric delay.
Rajesh Vaishnav, Erik Schmölter, Christoph Jacobi, Jens Berdermann, and Mihail Codrescu
Ann. Geophys., 39, 341–355, https://doi.org/10.5194/angeo-39-341-2021, https://doi.org/10.5194/angeo-39-341-2021, 2021
Short summary
Short summary
We investigate the delayed ionospheric response using the observed and CTIPe-model-simulated TEC against the solar EUV flux. The ionospheric delay estimated using model-simulated TEC is in good agreement with the delay estimated for observed TEC. The study confirms the model's capabilities to reproduce the delayed ionospheric response against the solar EUV flux. Results also indicate that the average delay is higher in the Northern Hemisphere as compared to the Southern Hemisphere.
Harikrishnan Charuvil Asokan, Jorge L. Chau, Raffaele Marino, Juha Vierinen, Fabio Vargas, Juan Miguel Urco, Matthias Clahsen, and Christoph Jacobi
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2020-974, https://doi.org/10.5194/acp-2020-974, 2020
Preprint withdrawn
Short summary
Short summary
This paper explores the dynamics of gravity waves and turbulence present in the mesosphere and lower thermosphere (MLT) region. We utilized two different techniques on meteor radar observations and simulations to obtain power spectra at different horizontal scales. The techniques are applied to a special campaign conducted in northern Germany in November 2018. The study revealed the dominance of large-scale structures with horizontal scales larger than 500 km during the campaign period.
Ales Kuchar, Petr Sacha, Roland Eichinger, Christoph Jacobi, Petr Pisoft, and Harald E. Rieder
Weather Clim. Dynam., 1, 481–495, https://doi.org/10.5194/wcd-1-481-2020, https://doi.org/10.5194/wcd-1-481-2020, 2020
Short summary
Short summary
Our study focuses on the impact of topographic structures such as the Himalayas and Rocky Mountains, so-called orographic gravity-wave hotspots. These hotspots play an important role in the dynamics of the middle atmosphere, in particular in the lower stratosphere. We study intermittency and zonally asymmetric character of these hotspots and their effects on the upper stratosphere and mesosphere using a new detection method in various modeling and observational datasets.
Christoph Geißler, Christoph Jacobi, and Friederike Lilienthal
Ann. Geophys., 38, 527–544, https://doi.org/10.5194/angeo-38-527-2020, https://doi.org/10.5194/angeo-38-527-2020, 2020
Short summary
Short summary
This is an extensive model study to analyze the migrating quarterdiurnal solar tide (QDT) and its forcing mechanisms in the middle atmosphere. We first show a climatology of the QDT amplitudes and examine the contribution of the different forcing mechanisms, including direct solar, nonlinear and gravity wave forcing, on the QDT amplitude. We then investigate the destructive interference between the individual forcing mechanisms.
Friederike Lilienthal, Erdal Yiğit, Nadja Samtleben, and Christoph Jacobi
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2019-339, https://doi.org/10.5194/gmd-2019-339, 2020
Preprint withdrawn
Short summary
Short summary
Gravity waves are a small-scale but prominent dynamical feature in the Earth's atmosphere. Here, we use a mechanistic nonlinear general circulation model and implement a modern whole atmosphere gravity wave parameterization. We study the response of the atmosphere on several phase speed spectra. We find a large influence of fast travelling waves on the background dynamics in the thermosphere and also a strong dependence of the amplitude of the terdiurnal solar tide, indicating wave interactions.
Erik Schmölter, Jens Berdermann, Norbert Jakowski, and Christoph Jacobi
Ann. Geophys., 38, 149–162, https://doi.org/10.5194/angeo-38-149-2020, https://doi.org/10.5194/angeo-38-149-2020, 2020
Short summary
Short summary
This study correlates ionospheric parameters with the integrated solar radiation for an analysis of the delayed ionospheric response in order to confirm previous studies on the delay and to further specify variations of the delay (seasonal and spatial). Results also indicate the dependence on the geomagnetic activity as well as on the 11-year solar cycle. The results are important for the understanding of ionospheric processes and could be used for the validation of ionospheric models.
Nadja Samtleben, Aleš Kuchař, Petr Šácha, Petr Pišoft, and Christoph Jacobi
Ann. Geophys., 38, 95–108, https://doi.org/10.5194/angeo-38-95-2020, https://doi.org/10.5194/angeo-38-95-2020, 2020
Short summary
Short summary
The additional transfer of momentum and energy induced by locally breaking gravity wave hotspots in the lower stratosphere may lead to a destabilization of the polar vortex, which is strongly dependent on the position of the hotspot. The simulations with a global circulation model show that hotspots located above Eurasia cause a total decrease in the stationary planetary wave (SPW) activity, while the impact of hotspots located in North America mostly increase the SPW activity.
Rajesh Vaishnav, Christoph Jacobi, and Jens Berdermann
Ann. Geophys., 37, 1141–1159, https://doi.org/10.5194/angeo-37-1141-2019, https://doi.org/10.5194/angeo-37-1141-2019, 2019
Short summary
Short summary
We investigate the ionospheric response to the temporal and spatial dynamics of the solar activity using total electron content (TEC) maps and multiple solar proxies. The maximum correlation at a 16–32-d timescale is observed between the He-II, Mg-II, and F30 with respect to global mean TEC, with an effective time delay of about 1 d. The most suitable proxy to represent the solar activity at the timescales of 16–32 d and 32–64 d is He-II.
Friederike Lilienthal and Christoph Jacobi
Ann. Geophys., 37, 943–953, https://doi.org/10.5194/angeo-37-943-2019, https://doi.org/10.5194/angeo-37-943-2019, 2019
Short summary
Short summary
We analyzed the forcing mechanisms of the migrating terdiurnal solar tide in the middle atmosphere, focusing the impact on the zonal mean circulation. We show that the primary solar forcing is the most dominant one but secondary wave–wave interactions also contribute in the lower thermosphere region. We further demonstrate that small-scale gravity waves can strongly and irregularly influence the amplitude of the terdiurnal tide as well as the background circulation in the thermosphere.
Christoph Jacobi and Christina Arras
Adv. Radio Sci., 17, 213–224, https://doi.org/10.5194/ars-17-213-2019, https://doi.org/10.5194/ars-17-213-2019, 2019
Short summary
Short summary
We analyze tidal phases and related wind shear in the mesosphere and
lower thermosphere as observed by a meteor radar. The wind shear phases are compared with those of sporadic E occurrence rates, which were derived from GPS radio occultation observations. We find good correspondence between radar derived wind shear and sporadic E phases for the semidiurnal, terdiurnal, and quarterdiurnal tidal components, but not for the diurnal tide.
Nadja Samtleben, Christoph Jacobi, Petr Pišoft, Petr Šácha, and Aleš Kuchař
Ann. Geophys., 37, 507–523, https://doi.org/10.5194/angeo-37-507-2019, https://doi.org/10.5194/angeo-37-507-2019, 2019
Short summary
Short summary
Simulations of locally breaking gravity wave hot spots in the stratosphere show a suppression of wave propagation at midlatitudes, which is partly compensated for by additional wave propagation through the polar region. This leads to a displacement of the polar vortex towards lower latitudes. The effect is highly dependent on the position of the artificial gravity wave forcing. It is strongest (weakest) for hot spots at lower to middle latitudes (higher latitudes).
Christoph Jacobi, Christina Arras, Christoph Geißler, and Friederike Lilienthal
Ann. Geophys., 37, 273–288, https://doi.org/10.5194/angeo-37-273-2019, https://doi.org/10.5194/angeo-37-273-2019, 2019
Short summary
Short summary
Sporadic E (Es) layers in the Earth's ionosphere are produced by ion convergence due to vertical wind shear in the presence of a horizontal component of the Earth's magnetic field. We present analyses of the 6 h tidal signatures in ES occurrence rates derived from GPS radio observations. Times of maxima in ES agree well with those of negative wind shear obtained from radar observation. The global distribution of ES amplitudes agrees with wind shear amplitudes from numerical modeling.
Daniel Mewes and Christoph Jacobi
Atmos. Chem. Phys., 19, 3927–3937, https://doi.org/10.5194/acp-19-3927-2019, https://doi.org/10.5194/acp-19-3927-2019, 2019
Short summary
Short summary
Horizontal moist static energy (MSE) transport patterns were extracted from reanalysis data using an artificial neuronal network for the winter months. The results show that during the last 30 years transport pathways that favour MSE transport through the North Atlantic are getting more frequent. This North Atlantic pathway is connected to positive temperature anomalies over the central Arctic, which implies a connection between Arctic amplification and the change in horizontal heat transport.
Sven Wilhelm, Gunter Stober, Vivien Matthias, Christoph Jacobi, and Damian J. Murphy
Ann. Geophys., 37, 1–14, https://doi.org/10.5194/angeo-37-1-2019, https://doi.org/10.5194/angeo-37-1-2019, 2019
Short summary
Short summary
This study shows that the mesospheric winds are affected by an expansion–shrinking of the mesosphere and lower thermosphere that takes place due to changes in the intensity of the solar radiation, which affects the density within the atmosphere. On seasonal timescales, an increase in the neutral density occurs together with a decrease in the eastward-directed zonal wind. Further, even after removing the seasonal and the 11-year solar cycle variations, we show a connection between them.
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
Short summary
Short summary
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.
Christoph Jacobi, Christoph Geißler, Friederike Lilienthal, and Amelie Krug
Adv. Radio Sci., 16, 141–147, https://doi.org/10.5194/ars-16-141-2018, https://doi.org/10.5194/ars-16-141-2018, 2018
Short summary
Short summary
The possible sources of the quarterdiurnal tide (QDT) in the middle atmosphere are still under discussion. Therefore, meteor radar winds were analyzed with respect to non-linear interaction, which probably plays a role in winter, but to a lesser degree in summer. Numerical model experiments lead to the conclusion that, although non-linear tidal interaction is indeed one source of the QDT, the major source is direct solar forcing of the 6-hr tidal components.
Erik Schmölter, Jens Berdermann, Norbert Jakowski, Christoph Jacobi, and Rajesh Vaishnav
Adv. Radio Sci., 16, 149–155, https://doi.org/10.5194/ars-16-149-2018, https://doi.org/10.5194/ars-16-149-2018, 2018
Short summary
Short summary
Physical and chemical processes in the ionosphere are driven by complex interactions with the solar radiation. The ionospheric plasma is in particular sensitive to solar variations with a time delay between one and two days.
Here we present preliminary results of the ionospheric delay based on a comprehensive and reliable database consisting of GNSS TEC Maps and EUV spectral flux data.
Gunter Stober, Jorge L. Chau, Juha Vierinen, Christoph Jacobi, and Sven Wilhelm
Atmos. Meas. Tech., 11, 4891–4907, https://doi.org/10.5194/amt-11-4891-2018, https://doi.org/10.5194/amt-11-4891-2018, 2018
Sabine Wüst, Thomas Offenwanger, Carsten Schmidt, Michael Bittner, Christoph Jacobi, Gunter Stober, Jeng-Hwa Yee, Martin G. Mlynczak, and James M. Russell III
Atmos. Meas. Tech., 11, 2937–2947, https://doi.org/10.5194/amt-11-2937-2018, https://doi.org/10.5194/amt-11-2937-2018, 2018
Short summary
Short summary
OH*-spectrometer measurements allow the analysis of gravity wave ground-based periods, but spatial information cannot necessarily be deduced. We combine the approach of Wachter at al. (2015) in order to derive horizontal wavelengths (but based on only one OH* spectrometer) with additional information about wind and temperature and compute vertical wavelengths. Knowledge of these parameters is a precondition for the calculation of further information such as the wave group velocity.
Christoph Jacobi, Tatiana Ermakova, Daniel Mewes, and Alexander I. Pogoreltsev
Adv. Radio Sci., 15, 199–206, https://doi.org/10.5194/ars-15-199-2017, https://doi.org/10.5194/ars-15-199-2017, 2017
Short summary
Short summary
There is continuous interest in coupling processes between the lower and middle atmosphere. Here we analyse midlatitude winds measured by radar at 82–97 km and find that especially in February they are positively correlated with El Niño. The signal is strong for the upper altitudes accessible to the radar, but weakens below. The observations can be qualitatively reproduced by numerical experiments using a mechanistic global circulation model.
Friederike Lilienthal, Christoph Jacobi, Torsten Schmidt, Alejandro de la Torre, and Peter Alexander
Ann. Geophys., 35, 785–798, https://doi.org/10.5194/angeo-35-785-2017, https://doi.org/10.5194/angeo-35-785-2017, 2017
Short summary
Short summary
Gravity waves (GWs) are one of the most important dynamical features of the middle atmosphere that extends from the tropopause to the lower thermosphere. They originate from the troposphere and propagate upward. Here, we show the impact of the horizontal GW distribution in the lower atmosphere on the dynamics of the middle atmosphere using a global circulation model. As a result, we find that non-zonal GW structures can force additional stationary planetary waves.
Gunter Stober, Vivien Matthias, Christoph Jacobi, Sven Wilhelm, Josef Höffner, and Jorge L. Chau
Ann. Geophys., 35, 711–720, https://doi.org/10.5194/angeo-35-711-2017, https://doi.org/10.5194/angeo-35-711-2017, 2017
Martin Kriegel, Norbert Jakowski, Jens Berdermann, Hiroatsu Sato, and Mogese Wassaie Mersha
Ann. Geophys., 35, 97–106, https://doi.org/10.5194/angeo-35-97-2017, https://doi.org/10.5194/angeo-35-97-2017, 2017
Petr Šácha, Friederike Lilienthal, Christoph Jacobi, and Petr Pišoft
Atmos. Chem. Phys., 16, 15755–15775, https://doi.org/10.5194/acp-16-15755-2016, https://doi.org/10.5194/acp-16-15755-2016, 2016
Short summary
Short summary
With a mechanistic model for the middle and upper atmosphere we performed sensitivity simulations to study a possible impact of a localized GW breaking hotspot in the eastern Asia–northern Pacific region and also the possible influence of the spatial distribution of gravity wave activity on the middle atmospheric circulation and transport. We show implications for polar vortex stability, in situ PW generation and longitudinal variability and strength of the Brewer–Dobson circulation.
Ch. Jacobi, N. Samtleben, and G. Stober
Adv. Radio Sci., 14, 169–174, https://doi.org/10.5194/ars-14-169-2016, https://doi.org/10.5194/ars-14-169-2016, 2016
Short summary
Short summary
VHF meteor radar observations of mesosphere/lower thermosphere daily temperatures have been performed at Collm, Germany. The data have been analyzed with respect to long-period oscillations at time scales of 2 to 30 days. The results reveal that oscillations with periods of up to 6 days are more frequently observed during summer, while those with longer periods have larger amplitudes during winter. The results are comparable with analyses from radar wind measurements.
Christoph Jacobi, Norbert Jakowski, Gerhard Schmidtke, and Thomas N. Woods
Adv. Radio Sci., 14, 175–180, https://doi.org/10.5194/ars-14-175-2016, https://doi.org/10.5194/ars-14-175-2016, 2016
Short summary
Short summary
The ionospheric response to solar extreme ultraviolet variability is shown by simple proxies based on Solar Dynamics Observatory/Extreme Ultraviolet Variability Experiment solar spectra. The daily proxies are compared with global mean total electron content. At time scales of the solar rotation up to about 40 days there is a time lag between EUV and TEC variability of about one day, with a tendency to increase for longer time scales.
P. Šácha, A. Kuchař, C. Jacobi, and P. Pišoft
Atmos. Chem. Phys., 15, 13097–13112, https://doi.org/10.5194/acp-15-13097-2015, https://doi.org/10.5194/acp-15-13097-2015, 2015
Short summary
Short summary
In this study, we present a discovery of an internal gravity wave activity and breaking hotspot collocated with an area of anomalously low annual cycle amplitude and specific dynamics in the stratosphere over the Northeastern Pacific/Eastern Asia coastal region. The reasons why this particular IGW activity hotspot was not discovered before nor the specific dynamics of this region pointed out are discussed together with possible consequences on the middle atmospheric dynamics and transport.
F. Lilienthal and Ch. Jacobi
Atmos. Chem. Phys., 15, 9917–9927, https://doi.org/10.5194/acp-15-9917-2015, https://doi.org/10.5194/acp-15-9917-2015, 2015
Short summary
Short summary
The quasi 2-day wave (QTDW), one of the most striking features in the mesosphere/lower thermosphere, is analyzed using meteor radar measurements at Collm (51°N, 13°E) during 2004-2014. The QTDW has periods lasting between 43 and 52h during strong summer bursts, and weaker enhancements are found during winter. A correlation between QTDW amplitudes and wind shear suggests baroclinic instability to be a likely forcing mechanism.
G. Schmidtke, Ch. Jacobi, B. Nikutowski, and Ch. Erhardt
Adv. Radio Sci., 12, 251–260, https://doi.org/10.5194/ars-12-251-2014, https://doi.org/10.5194/ars-12-251-2014, 2014
F. Lilienthal and Ch. Jacobi
Adv. Radio Sci., 12, 205–210, https://doi.org/10.5194/ars-12-205-2014, https://doi.org/10.5194/ars-12-205-2014, 2014
Ch. Jacobi
Adv. Radio Sci., 12, 161–165, https://doi.org/10.5194/ars-12-161-2014, https://doi.org/10.5194/ars-12-161-2014, 2014
Cited articles
Afraimovich, E. L., Astafyeva, E. I., Oinats, A. V., Yasukevich, Yu. V., and
Zhivetiev, I. V.: Global electron content: a new conception to track solar
activity, Ann. Geophys., 26, 335–344, https://doi.org/10.5194/angeo-26-335-2008, 2008.
Akmaev, R. A.: Whole atmosphere modeling: Connecting terrestrial and space
weather, Rev. Geophys., 49, RG4004, https://doi.org/10.1029/2011RG000364, 2011.
Appleton, E. V.: Two anomalies in the ionosphere, Nature, 157, 691, https://doi.org/10.1038/157691a0, 1946.
BenMoussa, A., Gissot, S., Schühle, U., Del Zanna, G., Auchère, F., Mekaoui,
S., Jones, A. R., Walton, D., Eyles, C. J., Thuillier, G., Seaton, D.,
Dammasch, I. E., Cessateur, G., Meftah, M., Andretta, V., Berghmans, D.,
Bewsher, D., Bolsée, D., Bradley, L., Brown, D. S., Chamberlin, P. C., Dewitte,
S., Didkovsky, L. V., Dominique, M., Eparvier, F. G., Foujols, T., Gillotay,
D., Giordanengo, B., Halain, J. P., Hock, R. A., Irbah, A., Jeppesen, C.,
Judge, D. L., Kretzschmar, M., McMullin, D. R., Nicula, B., Schmutz, W., Ucker,
G., Wieman, S., Woodraska, D., and Woods, T. N.: On-orbit degradation of
solar instruments, Sol. Phys., 288, 389–434, https://doi.org/10.1007/s11207-013-0290-z, 2013.
Bilitza, D., McKinnell, L. A., Reinisch, B., and Fuller-Rowell, T.: The
International Reference Ionosphere (IRI) today and in the future, J.
Geodesy., 85, 909–920, https://doi.org/10.1007/s00190-010-0427-x, 2011.
CDDIS: GNSS Atmospheric Products, available at:
http://cddis.nasa.gov/Data_and_Derived_Products/GNSS/atmospheric_products.html (last access: 29 June), 2017.
Chen, Y., Liu, L., and Wan, W.: Does the F10.7 index correctly describe
solar EUV flux during the deep solar minimum of 2007–2009?, J. Geophys.
Res., 116, A04304, https://doi.org/10.1029/2010JA016301, 2011.
Chen, Y., Liu, L., and Wan, W.: The discrepancy in solar EUV-proxy
correlations on solar cycle and solar rotation timescales and its
manifestation in the ionosphere, J. Geophys. Res., 117, A03313,
https://doi.org/10.1029/2011JA017224, 2012.
Codrescu, M. V., Fuller-Rowell, T. J., Munteanu, V., Minter, C. F., and
Millward, G. H.: Validation of the coupled thermosphere ionosphere
plasmasphere electrodynamics model: CTIPe-Mass Spectrometer Incoherent
Scatter temperature comparison, Adv. Space Res., 6, S09005,
https://doi.org/10.1029/2007SW000364, 2008.
Codrescu, M. V., Negrea, C., Fedrizzi, M., Fuller-Rowell, T. J., Dobin, A.,
Jakowsky, N., Khalsa, H., Matsuo, T., and Maruyama, N.: A real-time run of
the Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics (CTIPe)
model, Adv. Space Res., 10, S02001, https://doi.org/10.1029/2011SW000736, 2012.
DeWolfe, A. W., Wilson, A., Lindholm, D. M., Pankratz, C. K., Snow, M.
A., and Woods, T. N.: Solar Irradiance Data Products at the LASP Interactive
Solar Irradiance Datacenter (LISIRD), in: AGU Fall Meeting 2010, Abstract
GC21B-0881, San Francisco, California, USA, 2010.
Dudok de Wit, T., Kretzschmar, M., Lilensten, J., and Woods, T.: Finding the
best proxies for the solar UV irradiance, Geophys. Res. Lett., 36, L10107,
https://doi.org/10.1029/2009GL037825, 2009.
Fedrizzi, M., Fuller-Rowell, T. J., and Codrescu, M. V.: Global Joule
heating index derived from thermospheric density physics- based modeling and
observations, Adv. Space Res., 10, S03001, https://doi.org/10.1029/2011SW000724, 2012.
Fitzmaurice, A., Kunznetsova, M., Shim, J. S., and Uritskey, V.: Impact of
Solar Activity on the Ionosphere/Thermosphere during Geomagnetic Quiet Time
for CTIPe and TIE-GCM, Arxiv, Physics eprint, arXiv:1701.06525, 2017.
Forbes, J. M., Palo, S. E., and Zhang, X.: Variability of the ionosphere, J.
Atmos. Sol.-Terr. Phy., 62, 685–693, https://doi.org/10.1016/S1364-6826(00)00029-8,
2000.
Fuller-Rowell, T. J. and Rees, D.: A three-dimensional time-dependent global
model of the thermosphere, J. Atmos. Sci., 37, 2545–2567,
https://doi.org/10.1175/1520-0469(1980)037<2545:ATDTDG>2.0.CO;2,
1980.
Fuller-Rowell, T. J. and Rees, D.: Derivation of a conservation equation
for mean molecular weight for a two-constituent gas within a
three-dimensional, time-dependent model of the thermosphere, Planet. Space
Sci., 31, 1209–1222, https://doi.org/10.1016/0032-0633(83)90112-5, 1983.
Grinsted, A., Moore, J. C., and Jevrejeva, S.: Application of the cross
wavelet transform and wavelet coherence to geophysical time series,
Nonlinear Proc. Geoph., 11, 561–566, https://doi.org/10.5194/npg-11-561-2004,
2004.
Hanson W. B. and Moffett, R. J.: Ionization transport effects in the
equatorial F-region, J. Geophys. Res., 71, 5559–5572, https://doi.org/10.1029/JZ071i023p05559, 1966.
Hernandez-Pajares, M., Juan, J. M., Sanz, J., Orus, R., Garcia-Rigo, A.,
Feltens, J., Komjathy, A., Schaer, S. C., and Krankowski, A.: The IGS VTEC
maps: a reliable source of ionospheric information since 1998, J. Geodyn., 83,
263–275, https://doi.org/10.1007/s00190-008-0266-1, 2009.
Hinteregger, H. E., Fukui, K., and Gilson, B. R.: Observational, reference
and model data on solar EUV, from measurements on AE-E, Geophys. Res. Lett.,
8, 1147–1150, https://doi.org/10.1029/GL008i011p01147, 1981.
Hocke, K.: Oscillations of global mean TEC, J. Geophys. Res., 113, 1–13, A04302, https://doi.org/10.1029/2007JA012798, 2008.
IUP: Mg-II index, available at:
http://www.iup.uni-bremen.de/UVSAT/Datasets/mgii, last access:
30 June 2017.
Jacobi, C., Jakowski, N., Schmidtke, G., and Woods, T. N.: Delayed response
of the global total electron content to solar EUV variations, Adv. Radio
Sci., 14, 175–180, https://doi.org/10.5194/ars-14-175-2016, 2016.
Jakowski, N., Fichtelmann, B., and Jungstand, A.: Solar activity control of
Ionospheric and thermospheric processes, J. Atmos. Terr. Phys., 53,
1125–1130, https://doi.org/10.1016/0021-9169(91)90061-B, 1991.
LASP (2017): LASP Interactive Solar Irradiance Data Center,
available at: http://lasp.colorado.edu/lisird, last access: 30 June 2017.
Lean, J. L., White, O. R., Livingston, W. C., and Picone, J. M.: Variability
of a composite chromospheric irradiance index during the 11-year activity
cycle and over longer time periods, J. Geophys. Res., 106, 10645–10658,
https://doi.org/10.1029/2000JA000340, 2001.
Lean, J. L., Woods, T. N., Eparvier, F. G., Meier, R. R., Strickland, D. J.,
Correira, J. T., and Evans, J. S.: Solar extreme ultraviolet irradiance:
Present, past, and future, J. Geophys. Res., 116, A01102,
https://doi.org/10.1029/2010JA015901, 2011.
Lee, C. K., Han, S. C., Bilitza, D., and Seo, K. W.: Global characteristics
of the correlation and time lag between solar and ionospheric parameters in
the 27-day period, J. Atmos. Sol-Terr. Phy., 77, 219–224, https://doi.org/10.1016/j.jastp.2012.01.010, 2012.
Liu, L., Wan, W., Ning, B., Pirog, O. M., and Kurkin V. I.: Solar activity
variations of the ionospheric peak electron density, J. Geophys. Res., 111,
A08304, https://doi.org/10.1029/2006JA011598, 2006.
Maruyama, T.: Solar proxies pertaining to empirical ionospheric total
electron content models, J. Geophy. Res., 15, A04306,
https://doi.org/10.1029/2009JA014890, 2010.
McNamara, L. F. and Smith, D. H.: Total electron content of the ionosphere
at 31 S, 1967–1974, J. Atmos. Terr. Phys., 44, 227–239, https://doi.org/10.1016/0021-9169(82)90028-9, 1982.
Millward, G. H., Moffett, R. J., Quegan, S., and Fuller-Rowell, T. J.: A
coupled thermosphere-ionosphere-plasmasphere model (CTIP), in:
Solar-Terrestrial Energy Program: Handbook of Ionospheric Models, edited by:
Schunk, R. W., Cent. for Atmos. and Space Sci., Utah State
Univ., Logan, Utah, USA, 239–279, 1996.
Millward, G. H., Müller-Wodarg, I. C. F., Aylward, A. D., Fuller-Rowell,
T. J., Richmond, A. D., and Moffett, R. J.: An investigation into the
influence of tidal forcing on F region equatorial vertical ion drift using a
global ionosphere-thermosphere model with coupled electrodynamics, J.
Geophys. Res., 106, 24733–24744, https://doi.org/10.1029/2000JA000342, 2001.
Min, K., Park, J., Kim, H., Kim, V., Kil, H., Lee, J., Rentz, S., Lühr,
H., and Paxton, L.: The 27-day modulation of the low-latitude ionosphere
during a solar maximum, J. Geophys. Res., 114, A04317,
https://doi.org/10.1029/2008JA013881, 2009.
Negrea, C., Codrescu, M. V., and Fuller-Rowell, T. J.: On the validation
effort of the Coupled Thermosphere Ionosphere Plasmasphere Electrodynamics
model, Adv. Space Res., 10, S08010, https://doi.org/10.1029/2012SW000818, 2012.
Noll, C.: The Crustal Dynamics Data Information System: A resource to
support scientific analysis using space geodesy, Adv. Space Res., 45,
1421–1440, https://doi.org/10.1016/j.asr.2010.01.018, 2010.
Oinats, A. V., Ratovsky, K. G., and Kotovich, G. V.: Influence of the 27-day
solar flux variations on the ionosphere parameters measured at Irkutsk in
2003–2005, Adv. Space Res., 42, 639–644, https://doi.org/10.1016/j.asr.2008.02.009,
2008.
Pesnell, W. D., Thompson, B. J., and Chamberlin, P. C.: The Solar Dynamics
Observatory (SDO), Solar Phys., 275, 3–15, https://doi.org/10.1007/s11207-011-9841-3,
2012.
Quegan, S., Bailey, G. J., Moffett, R. J., Heelis, R. A., Fuller-Rowell, T.
J., Rees, D., and Spiro, R. W.: A theoretical study of the distribution of
ionization in the high-latitude ionosphere and the plasmasphere: First
results on the mid-latitude trough and the light-ion trough, J. Atmos. Terr.
Phys., 44, 619–640, https://doi.org/10.1016/0021-9169(82)90073-3, 1982.
Rawer, K., Bilitza, D., and Ramakrishnan, S.: Goals and status of the
International Reference Ionosphere, Rev. Geophys., 16, 177–181,
https://doi.org/10.1029/RG016i002p00177,1978.
Richmond, A. D., Ridley, E. C., and Roble, R. G.: A thermosphere/ionosphere
general circulation model with coupled electrodynamics, Geophys. Res. Lett.,
19, 601–604, https://doi.org/10.1029/92GL00401, 1992.
Rishbeth, H.: Day-to-day ionospheric variations in a period of high solar
activity, J. Atmos. Terr. Phys., 55, 165–171, https://doi.org/10.1016/0021-9169(93)90121-E, 1993.
Roble, R. G., Ridley, E. C., Richmond, A. D., and Dickinson, R. E.: A coupled
thermosphere/ionosphere general circulation model, Geophys. Res. Lett.,
15, 1325–1328, https://doi.org/10.1029/GL015i012p01325, 1988.
Sterling, D. L., Hanson, W. B., Moffett, R. J., and Baxter, R. G.: Influence
of electromagnetic drift and neutral air winds on some features of the
F2-region, Radio Sci., 4, 1005–1023, https://doi.org/10.1029/RS004i011p01005, 1969.
Su, Y. Z., Bailey, G. J., and Fukao, S.: Altitude dependencies in the solar
activity variations of the ionospheric electron density, J. Geophys. Res.,
104, 14879–14891, https://doi.org/10.1029/1999JA900093, 1999.
Tapping, K. F.: Recent solar radio astronomy at centimeter wavelengths:
The temporal variability of the 10.7 cm flux, J. Geophys. Res., 92,
829–838, https://doi.org/10.1029/JD092iD01p00829, 1987.
Unglaub, C., Jacobi, C., Schmidtke, G., Nikutowski, B., and Brunner, R.:
EUV-TEC proxy to describe ionospheric variability using satellite-borne
solar EUV measurements: First results, Adv. Space Res., 47, 1578–1584,
https://doi.org/10.1016/j.asr.2010.12.014, 2011.
Unglaub, C., Jacobi, Ch., Schmidtke, G., Nikutowski, B., and Brunner, R.:
EUV-TEC proxy to describe ionospheric variability using satellite-borne solar
EUV measurements, Adv. Radio Sci., 10, 259–263,
https://doi.org/10.5194/ars-10-259-2012, 2012.
Viereck, R., Puga, L., McMullin, D., Judge, D., Weber, M., and Tobiska,
W. K.: The Mg II index: A proxy for solar EUV, Geophys. Res. Lett., 28,
1343–1346, https://doi.org/10.1029/2000GL012551, 2001.
Wintoft, P.: The variability of solar EUV: A multiscale comparison between
sunspot number, 10.7 cm flux, LASP MgII index, and SOHO/SEM EUV flux, J.
Atmos. Sol. Terr. Phys., 73, 1708–1714, https://doi.org/10.1016/j.jastp.2011.03.009,
2011.
Woods, T. N. and Eparvier, F. G.: Solar ultraviolet variability during the
TIMED mission, Adv. Space Res., 37, 219–224, https://doi.org/10.1016/j.asr.2004.10.006,
2006.
Woods, T. N. and Rottman, G.: Solar ultraviolet variability over time periods
of aeronomic interest, in: Atmospheres in the Solar System: Comparative
Aeronomy, Geophys. Monogr. Ser., vol. 130, edited by: Mendillo, M., Nagy, A.,
and Waite, J. H., 221–234, AGU, Washington, DC, https://doi.org/10.1029/130GM14, 2002.
Woods, T. N., Bailey, S., Eparvier, F., Lawrence, G., Lean, J., McClintock,
B., Roble, R., Rottmann, G. J., Solomon, S. C., Tobiska, W. K., and White,
O. R.: TIMED Solar EUV Experiment, Phys. Chem. Earth Pt. C, 25, 393–396,
https://doi.org/10.1016/S1464-1917(00)00040-4, 2000.
Woods, T. N., Eparvier, F., Bailey, S., Chamberlin, P., Lean, J., Rottmann,
G. J., Solomon, S. C., Tobiska, W. K., and Woodraska, D. L.: Solar EUV
Experiment (SEE): Mission overview and first results, J. Geophys. Res., 110,
A01312, https://doi.org/10.1029/2004JA010765, 2005.
Woods, T. N., Eparvier, F. G., Hock, R., Jones, A. R., Woodraska, D., Judge,
D., Didkovsky, L., Lean, J., Mariska, J., Warren, H., McMullin, D.,
Chamberlin, P., Berthiaume, G., Bailey, S., Fuller-Rowell, T., Sojka, J.,
Tobiska, W. K., and Viereck, R.: Extreme Ultraviolet Variability Experiment
(EVE) on the Solar Dynamics Observatory (SDO): Overview of Science
Objectives, Instrument Design, Data Products, and Model Developments, Sol. Phys., 275, 115–143, https://doi.org/10.1007/s11207-009-9487-6, 2012.
Short summary
We investigate the ionospheric response to solar Extreme Ultraviolet (EUV) variations using different solar proxies and IGS TEC maps. An ionospheric delay in GTEC is observed at the 27 days solar rotation period with the time scale of about ~ 1–2 days. Here we present preliminary results from the CTIPe model simulations which qualitatively reproduce the observed ~1-2 days delay in GTEC, which is might be due to vertical transport processes.
We investigate the ionospheric response to solar Extreme Ultraviolet (EUV) variations using...
