Bibliography

Ionospheric response to solar and magnetospheric protons during January 15–22, 2005: EAGLE whole atmosphere model results

We present an analysis of the ionosphere and thermosphere response to Solar Proton Events (SPE) and magnetospheric proton precipitation in January 2005, which was carried out using the model of the entire atmosphere EAGLE. The ionization rates for the considered period were acquired from the AIMOS (Atmospheric Ionization Module Osnabrück) dataset. For numerical experiments, we applied only the proton-induced ionization rates of that period, while all the other model input parameters, including the electron precipitations, corresponded to the quiet conditions. In January 2005, two major solar proton events with different energy spectra and proton fluxes occurred on January 17 and January 20. Since two geomagnetic storms and several sub-storms took place during the considered period, not only solar protons but also less energetic magnetospheric protons contributed to the calculated ionization rates. Despite the relative transparency of the thermosphere for high-energy protons, an ionospheric response to the SPE and proton precipitation from the magnetotail was obtained in numerical experiments. In the ionospheric E layer, the maximum increase in the electron concentration is localized at high latitudes, and at heights of the ionospheric F2 layer, the positive perturbations were formed in the near-equatorial region. An analysis of the model-derived results showed that changes in the ionospheric F2 layer were caused by a change in the neutral composition of the thermosphere. We found that in the recovery phase after both solar proton events and the enhancement of magnetospheric proton precipitations associated with geomagnetic disturbances, the TEC and electron density in the F region and in topside ionosphere/plasmasphere increase at low- and mid-latitudes due to an enhancement of atomic oxygen concentration. Our results demonstrate an important role of magnetospheric protons in the formation of negative F-region ionospheric storms. According to our results, the topside ionosphere/plasmasphere and bottom-side ionosphere can react to solar and magnetospheric protons both with the same sign of disturbances or in different way. The same statement is true for TEC and foF2 disturbances. Different disturbances of foF2 and TEC at high and low latitudes can be explained by topside electron temperature disturbances.

Bessarab, F.; Sukhodolov, T.; Klimenko, M.; Klimenko, V.; Korenkov, Yu.; Funke, B.; Zakharenkova, I.; Wissing, J.; Rozanov, E.;

Published by: Advances in Space Research      Published on: jan

YEAR: 2021     DOI: 10.1016/j.asr.2020.10.026

Ionosphere; Proton precipitations; Solar proton events; thermosphere; Whole atmosphere model

Ionospheric response to solar and magnetospheric protons during January 15—22, 2005: EAGLE whole atmosphere model results

We present an analysis of the ionosphere and thermosphere response to Solar Proton Events (SPE) and magnetospheric proton precipitation in January 2005, which was carried out

Bessarab, Fedor; Sukhodolov, Timofei; Klimenko, Maxim; Klimenko, Vladimir; Korenkov, Yu; Funke, Bernd; Zakharenkova, Irina; Wissing, Jan; Rozanov, EV;

Published by: Advances in Space Research      Published on:

YEAR: 2021     DOI: 10.1016/j.asr.2020.10.026

Climatology characteristics of ionospheric irregularities described with GNSS ROTI

the Global Ultraviolet Imager (GUVI) settled on the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) mission spacecraft. The GUVI-based model is completely

Kotulak, Kacper; Zakharenkova, Irina; Krankowski, Andrzej; Cherniak, Iurii; Wang, Ningbo; Fron, Adam;

Published by: Remote Sensing      Published on:

YEAR: 2020     DOI: 10.3390/rs12162634

ROTI Maps: a new IGS ionospheric product characterizing the ionospheric irregularities occurrence

The International GNSS Service (IGS) has recently accepted for official release a new ionospheric product to characterize ionospheric irregularity and intensity as derived from multi-site ground-based GPS observations. This product was developed and implemented in the Space Radio-Diagnostic Research Center (SRRC), University of Warmia and Mazury. The SRRC has implemented this approach using in-house software for multi-step processing and interpretation of carrier phase delays in dual-frequency GPS signals and provides the new product to the IGS database. We used measurements with 30-s sampling rate from about 700 GPS stations located at high and middle latitudes of the Northern Hemisphere. The product represents changes in the GPS-based Rate of TEC Index (ROTI) and has a polar projection within a range of 50\textdegree\textendash90\textdegreeN in geomagnetic latitude and 00\textendash24 magnetic local time. The new service allows regular monitoring of ionospheric irregularities over the Northern Hemisphere. We demonstrate results of visualization and analysis of the IGS ROTI Maps product for representative periods with geomagnetically quiet conditions and severe geomagnetic storms in 2014\textendash2015 in order to demonstrate the performance and ability of this product to depict the development of ionospheric irregularities in the area of interest. During space weather events, the ionospheric irregularities oval, as deduced from the ROTI Maps, expands significantly in size toward midlatitudes with simultaneous increase in irregularities intensity, which can lead to degradation of the GPS precise positioning performance at lower latitudes.

Cherniak, Iurii; Krankowski, Andrzej; Zakharenkova, Irina;

Published by: GPS Solutions      Published on: 06/2018

YEAR: 2018     DOI: 10.1007/s10291-018-0730-1

Study of the Equatorial and Low-Latitude Electrodynamic and Ionospheric Disturbances During the 22\textendash23 June 2015 Geomagnetic Storm Using Ground-Based and Spaceborne Techniques

We use a set of ground-based instruments (Global Positioning System receivers, ionosondes, magnetometers) along with data of multiple satellite missions (Swarm, C/NOFS, DMSP, GUVI) to analyze the equatorial and low-latitude electrodynamic and ionospheric disturbances caused by the geomagnetic storm of 22\textendash23 June 2015, which is the second largest storm in the current solar cycle. Our results show that at the beginning of the storm, the equatorial electrojet (EEJ) and the equatorial zonal electric fields were largely impacted by the prompt penetration electric fields (PPEF). The PPEF were first directed eastward and caused significant ionospheric uplift and positive ionospheric storm on the dayside, and downward drift on the nightside. Furthermore, about 45\ min after the storm commencement, the interplanetary magnetic field (IMF) Bz component turned northward, leading to the EEJ changing sign to westward, and to overall decrease of the vertical total electron content (VTEC) and electron density on the dayside. At the end of the main phase of the storm, and with the second long-term IMF Bz southward turn, we observed several oscillations of the EEJ, which led us to conclude that at this stage of the storm, the disturbance dynamo effect was already in effect, competing with the PPEF and reducing it. Our analysis showed no significant upward or downward plasma motion during this period of time; however, the electron density and the VTEC drastically increased on the dayside (over the Asian region). We show that this second positive storm was largely influenced by the disturbed thermospheric conditions.

Astafyeva, E.; Zakharenkova, I.; Hozumi, K.; Alken, P.; isson, Co; Hairston, M.; Coley, W.;

Published by: Journal of Geophysical Research: Space Physics      Published on: 03/2018

YEAR: 2018     DOI: 10.1002/jgra.v123.310.1002/2017JA024981

Features of High-Lat Ionospheric Irregularities Development as Revealed by Ground-Based GPS Observations, Satellite-Borne GPS Observations and Satellite In Situ Measurements over the Territory of Russia during the Geomagnetic Storm on March 17-18, 2015

The dynamic picture of the response of the high- and mid-latitude ionosphere to the strong geomagnetic disturbances on March 17-18, 2015, has been studied with ground-based and satellite observations, mainly, by transionospheric measurements of delays of GPS (Global Positioning System) signals. The advantages of the joint use of ground-based GPS measurements and GPS measurements on board of the Swarm Low-Earth-Orbit satellite mission for monitoring of the appearance of ionospheric irregularities over the territory of Russia are shown for the first time. The results of analysis of ground-based and space-borne GPS observations, as well as satellite, in situ measurements, revealed large-scale ionospheric plasma irregularities observed over the territory of Russia in the latitude range of 50^o - 85^o N during the main phase of the geomagnetic storm. The most intense ionospheric irregularities were detected in the auroral zone and in the region of the main ionospheric trough (MIT). It has been found that sharp changes in the phase of the carrier frequency of the navigation signal from all tracked satellites were recorded at all GPS stations located to the North from 55^o MLAT. The development of a deep MIT was related to dynamic processes in the subauroral ionosphere, in particular, with electric fields of the intense subauroral polarization stream. Analysis of the electron and ion density values obtained by instruments on board of the Swarm and DMSP satellites showed that the zone of highly structured auroral ionosphere extended at least to heights of 850-900 km.

Zakharenkova, I.; Cherniak, Iu.; Shagimuratov, I.; Klimenko, M.;

Published by: Geomagnetism and Aeronomy      Published on: 01/2018

YEAR: 2018     DOI: 10.1134/S0016793217050176

Study of the equatorial and low-latitude electrodynamic and ionospheric disturbances during the 22—23 June 2015 geomagnetic storm using ground-based and spaceborne techniques

We use a set of ground-based instruments (Global Positioning System receivers, ionosondes, magnetometers) along with data of multiple satellite missions (Swarm, C/NOFS, DMSP, GUVI) to analyze the equatorial and low-latitude electrodynamic and ionospheric disturbances caused by the geomagnetic storm of 22–23 June 2015, which is the second largest storm in the current solar cycle.

Astafyeva, E; Zakharenkova, I; Hozumi, K; Alken, P; isson, Co; Hairston, Marc; Coley, William;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2018     DOI: 10.1002/2017JA024981

Study of the equatorial and low-latitude electrodynamic and ionospheric disturbances during the 22—23 June 2015 geomagnetic storm using ground-based and spaceborne techniques

Astafyeva, E; Zakharenkova, I; Hozumi, K; Alken, P; isson, Co; Hairston, Marc; Coley, William;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2018     DOI:

Observations of the Weddell Sea Anomaly in the ground-based and space-borne TEC measurements

The Weddell Sea Anomaly (WSA) is a summer ionospheric anomaly, which is characterized by a greater nighttime ionospheric density than that in daytime in the region near the Weddell Sea. We investigate the WSA signatures in the ground-based TEC (vertical total electron content) by using GPS and GLONASS measurements of the dense regional GNSS networks in South America. We constructed the high-resolution regional TEC maps for December 2014–January 2015. The WSA effects of the TEC exceed the noontime values are registered starting from 17 LT, it reaches its maximum at 01–05 LT and starts to disappear after 09 LT.

Zakharenkova, Irina; Cherniak, Iurii; Shagimuratov, Irk;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on:

YEAR: 2017     DOI: 10.1016/j.jastp.2017.06.014

Prompt penetration electric fields and the extreme topside ionospheric response to the June 22--23, 2015 geomagnetic storm as seen by the Swarm constellation

Using data from the three Swarm satellites, we study the ionospheric response to the intense geomagnetic storm of June 22\textendash23, 2015. With the minimum SYM-H excursion of -207 nT, this storm is so far the second strongest geomagnetic storm in the current 24th solar cycle. A specific configuration of the Swarm satellites allowed investigation of the evolution of the storm-time ionospheric alterations on the day- and the nightside quasi-simultaneously. With the development of the main phase of the storm, a significant dayside increase of the vertical total electron content (VTEC) and electron density Ne was first observed at low latitudes on the dayside. From\ ~22\ UT of 22 June to\ ~1\ UT of 23 June, the dayside experienced a strong negative ionospheric storm, while on the nightside an extreme enhancement of the topside VTEC occurred at mid-latitudes of the northern hemisphere. Our analysis of the equatorial electrojet variations obtained from the magnetic Swarm data indicates that the storm-time penetration electric fields were, most likely, the main driver of the observed ionospheric effects at the initial phase of the storm and at the beginning of the main phase. The dayside ionosphere first responded to the occurrence of the strong eastward equatorial electric fields. Further, penetration of westward electric fields led to gradual but strong decrease of the plasma density on the dayside in the topside ionosphere. At this stage, the disturbance dynamo could have contributed as well. On the nightside, the observed extreme enhancement of the Ne and VTEC in the northern hemisphere (i.e., the summer hemisphere) in the topside ionosphere was most likely due to the combination of the prompt penetration electric fields, disturbance dynamo and the storm-time thermospheric circulation. From\ ~2.8\ UT, the ionospheric measurements from the three Swarm satellites detected the beginning of the second positive storm on the dayside, which was not clearly associated with electrojet variations. We find that this second storm might be provoked by other drivers, such as an increase in the thermospheric composition.

Astafyeva, Elvira; Zakharenkova, Irina; Alken, Patrick;

Published by: Earth, Planets and Space      Published on: 09/2016

YEAR: 2016     DOI: 10.1186/s40623-016-0526-x

High-latitude ionospheric irregularities: differences between ground- and space-based GPS measurements during the 2015 St. Patrick\textquoterights Day storm

We present an analysis of ionospheric irregularities at high latitudes during the 2015 St. Patrick\textquoterights Day storm. Our study used measurements from\ ~2700 ground-based GPS stations and GPS receivers onboard five low earth orbit (LEO) satellites\textemdashSwarm A, B and C, GRACE and TerraSAR-X\textemdashthat had close orbit altitudes of\ ~500\ km, and the Swarm in situ plasma densities. An analysis of the rate of TEC index (ROTI) derived from LEO\textendashGPS data, together with Swarm in situ plasma probe data, allowed us to examine the topside ionospheric irregularities and to compare them to the main ionospheric storm effects observed in ground-based GPS data. We observed strong ionospheric irregularities in the topside ionosphere during the storm\textquoterights main phase that were associated with storm-enhanced density (SED) formation at mid-latitudes and further evolution of the SED plume to the polar tongue of ionization (TOI). Daily ROTI maps derived from ground-based and LEO\textendashGPS measurements show the pattern of irregularities oriented in the local noon\textendashmidnight direction, which is a signature of SED/TOI development across the polar cap region. Analysis of the Swarm in situ plasma measurements revealed that, during the storm\textquoterights main phase, all events with extremely enhanced plasma densities (\>10⁶\ el/cm³) in the polar cap were observed in the Southern Hemisphere. When Swarm satellites crossed these enhancements, degradation of GPS performance was observed, with a sudden decrease in the number of GPS satellites tracked. Our findings indicate that polar patches and TOI structures in the topside ionosphere were predominantly observed in the Southern Hemisphere, which had much higher plasma densities than the Northern Hemisphere, where SED/TOI structures have already been reported earlier. LEO\textendashGPS data (ROTI and topside TEC) were consistent with these results.

Cherniak, Iurii; Zakharenkova, Irina;

Published by: Earth, Planets and Space      Published on: 07/2016

YEAR: 2016     DOI: 10.1186/s40623-016-0506-1

High-latitude ionospheric irregularities: differences between ground-and space-based GPS measurements during the 2015 St. Patrick’s Day storm

We present an analysis of ionospheric irregularities at high latitudes during the 2015 St. Patrick’s Day storm. Our study used measurements from ~2700 ground-based GPS stations and

Cherniak, Iurii; Zakharenkova, Irina;

Published by: Earth, Planets and Space      Published on:

YEAR: 2016     DOI: 10.1186/s40623-016-0506-1

Dependence of the high-latitude plasma irregularities on the auroral activity indices: a case study of 17 March 2015 geomagnetic storm

The magnetosphere substorm plays a crucial role in the solar wind energy dissipation into the ionosphere. We report on the intensity of the high-latitude ionospheric irregularities during one of the largest storms of the current solar cycle\textemdashthe St. Patrick\textquoterights Day storm of 17 March 2015. The database of more than 2500 ground-based Global Positioning System (GPS) receivers was used to estimate the irregularities occurrence and dynamics over the auroral region of the Northern Hemisphere. We analyze the dependence of the GPS-detected ionospheric irregularities on the auroral activity. The development and intensity of the high-latitude irregularities during this geomagnetic storm reveal a high correlation with the auroral hemispheric power and auroral electrojet indices (0.84 and 0.79, respectively). Besides the ionospheric irregularities caused by particle precipitation inside the polar cap region, evidences of other irregularities related to the storm enhanced density (SED), formed at mid-latitudes and its further transportation in the form of tongue of ionization (TOI) towards and across the polar cap, are presented. We highlight the importance accounting contribution of ionospheric irregularities not directly related with particle precipitation in overall irregularities distribution and intensity.

Cherniak, Iurii; Zakharenkova, Irina;

Published by: Earth, Planets and Space      Published on: 12/2015

YEAR: 2015     DOI: 10.1186/s40623-015-0316-x

Auroral hemispheric power index Auroral precipitation; geomagnetic storm; GPS; Ionosphere irregularities; ROTI

Ionospheric response to the 2015 St. Patrick's Day storm: A global multi-instrumental overview

We present the first multi-instrumental results on the ionospheric response to the geomagnetic storm of 17\textendash18 March 2015 (the St. Patrick\textquoterights Day storm) that was up to now the strongest in the 24th solar cycle (minimum SYM-H value of -233 nT). The storm caused complex effects around the globe. The most dramatic positive ionospheric storm occurred at low latitudes in the morning (~100\textendash150\% enhancement) and postsunset (~80\textendash100\% enhancement) sectors. These significant vertical total electron content increases were observed in different local time sectors and at different universal time, but around the same area of the Eastern Pacific region, which indicates a regional impact of storm drivers. Our analysis revealed that this particular region was most concerned by the increase in the thermospheric O/N₂\ ratio. At midlatitudes, we observe inverse hemispheric asymmetries that occurred, despite the equinoctial period, in different longitudinal regions. In the European-African sector, positive storm signatures were observed in the Northern Hemisphere (NH), whereas in the American sector, a large positive storm occurred in the Southern Hemisphere, while the NH experienced a negative storm. The observed asymmetries can be partly explained by the thermospheric composition changes and partly by the hemispherically different nondipolar portions of the geomagnetic field as well as by the IMF By component variations. At high latitudes, negative ionospheric storm effects were recorded in all longitudinal regions, especially the NH of the Asian sector was concerned. The negative storm phase developed globally on 18 March at the beginning of the recovery phase.

Astafyeva, Elvira; Zakharenkova, Irina; Förster, Matthias;

Published by: Journal of Geophysical Research: Space Physics      Published on: 10/2015

YEAR: 2015     DOI: 10.1002/2015JA021629

geomagnetic storm; hemispheric asymmetry; Ionosphere; negative storm; positive storm; Swarm mission

Dynamics of the high-latitude ionospheric irregularities during the 17 March 2015 St. Patrick's Day storm: Ground-based GPS measurements

We report first results on the study of the high-latitude ionospheric irregularities observed in worldwide GPS data during the St. Patrick\textquoterights Day geomagnetic storm (17 March 2015). Multisite GPS observations from more than 2500 ground-based GPS stations were used to analyze the dynamics of the ionospheric irregularities in the Northern and Southern Hemispheres. The most intense ionospheric irregularities lasted for more than 24 h starting at 07 UT of 17 March. This period correlates well with an increase of the auroral Hemispheric Power index. We find hemispheric asymmetries in the intensity and spatial structure of the ionospheric irregularities. Over North America, the ionospheric irregularities zone expanded equatorward below ~45\textdegreeN geographic latitude. Additionally, the strong midlatitude and high-latitude GPS phase irregularities in the auroral oval were found to be related to the formation of storm enhanced density and deepening of the main ionospheric trough through upper atmosphere ionization by energetic particle precipitation. Significant increases in the intensity of the irregularities within the polar cap region of both hemispheres were associated with the formation and evolution of the storm enhanced density/tongue of ionization structures and polar patches.

Cherniak, Iurii; Zakharenkova, Irina; Redmon, Robert;

Published by: Space Weather      Published on: 09/2015

YEAR: 2015     DOI: 10.1002/swe.v13.910.1002/2015SW001237

auroral precipitation; geomagnetic storm; Ionosphere; irregularities; rate of TEC

The global morphology of the plasmaspheric electron content during Northern winter 2009 based on GPS/COSMIC observation and GSM TIP model results

We studied the contribution of the global plasmaspheric and ionospheric electron content (PEC and IEC) into total electron content (TEC). The experimental PEC was estimated by comparison of GPS TECobservations and FORMOSAT-3/COSMIC radio occultation IEC measurements. Results are retrieved for the winter solstice (January and December 2009) conditions. Global maps of COSMIC-derived IEC, PECand GPS TEC were compared with Global Self-consistent Model of the Thermosphere, Ionosphere and Protonosphere (GSM TIP) results. In addition, we used GSM TIP model results in order to estimate the contribution of plasmaspheric electron content into TEC value at the different altitudinal regions. The advantages and problems of the outer ionospheric/plasmaspheric parameters (O⁺/H⁺ transition height,TEC and electron density at height above F2 layer peak) representation by the IRI (International Reference Ionosphere) model are discussed.

Klimenko, M.V.; Klimenko, V.V.; Zakharenkova, I.E.; Cherniak, Iu.V.;

Published by: Advances in Space Research      Published on: 06/2014

YEAR: 2015     DOI: 10.1016/j.asr.2014.06.027

FORMOSAT-3/COSMIC; GPS; Numerical modeling; Plasmasphere; total electron content

Ionospheric and Thermospheric Response to the 2015 St. Patrick s Day Storm: a Global Multi-Instrumental Overview

We study the ionospheric response to the geomagnetic storm of 17-18 March 2015 (the St. Patrick s Day 2015 storm) that was up to now the strongest in the 24th solar cycle (minimum

Astafyeva, Elvira; Zakharenkova, Irina; Foerster, Matthias; Doornbos, Eelco; Encarnacao, Joao; Siemes, Christian;

Published by:       Published on:

YEAR: 2015     DOI: