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Found 22 entries in the Bibliography.
Showing entries from 1 through 22
2022 |
An extensive intercomparison of ionospheric foF2 observations and NCAR Thermosphere-Ionosphere ElectrodynamicsGeneral Circulation Model(TIE-GCM)simulations has been carried out for the dip equatorial location of Thiruvananthapuram. Ionosonde measurements for geomagnetically quiet days of 2002, 2006 and 2008, representing solar maximum, solar minimum and deep solar minimum conditions have been used for the analysis. In general TIE-GCM simulations reproduced the temporal and seasonal characteristics of foF2 over Thiruvananthap ... Mridula, N.; Manju, G.; Sijikumar, S.; Pant, Tarun; Published by: Advances in Space Research Published on: may YEAR: 2022   DOI: 10.1016/j.asr.2022.02.018 |
Total Electron Content Variations during an HSS/CIR driven storm at high and middle latitudes
Geethakumari, Gopika; Aikio, Anita; Cai, Lei; Vanhamaki, Heikki; Pedersen, Marcus; Coster, Anthea; Marchaudon, Aurélie; Blelly, Pierre-Louis; Haberle, Veronika; Maute, Astrid; Ellahouny, Nada; Virtanen, Ilkka; Norberg, Johannes; Soyama, Shin-Ichiro; Grandin, Maxime; Published by: Published on: mar YEAR: 2022   DOI: 10.5194/egusphere-egu22-8194 |
The ionospheric effects of six intense geomagnetic storms with Dst index ≤ −100 nT that occurred in 2012 were studied at a low-latitude station, Darwin (Geomagnetic coordinates, 21.96° S, 202.84° E), a low-mid-latitude station, Townsville (28.95° S, 220.72° E), and a mid-latitude station, Canberra (45.65° S, 226.30° E), in the Australian Region, by analyzing the storm–time variations in the critical frequency of the F2-region (foF2). Out of six storms, a storm of 23–24 April did not produce any ionospheric effe ... Published by: Atmosphere Published on: mar YEAR: 2022   DOI: 10.3390/atmos13030480 Geomagnetic storms; \textbfE × \textbfB drifts; disturbance dynamo electric fields; prompt penetrating electric fields; storm-induced circulation |
The ionospheric effects of six intense geomagnetic storms with Dst index ≤ −100 nT that occurred in 2012 were studied at a low-latitude station, Darwin (Geomagnetic coordinates, 21.96° S, 202.84° E), a low-mid-latitude station, Townsville (28.95° S, 220.72° E), and a mid-latitude station, Canberra (45.65° S, 226.30° E), in the Australian Region, by analyzing the storm–time variations in the critical frequency of the F2-region (foF2). Out of six storms, a storm of 23–24 April did not produce any ionospheric effe ... Published by: Atmosphere Published on: mar YEAR: 2022   DOI: 10.3390/atmos13030480 Geomagnetic storms; \textbfE × \textbfB drifts; disturbance dynamo electric fields; prompt penetrating electric fields; storm-induced circulation |
Ionospheric response of St. Patrick’s Day geomagnetic storm over Indian low latitude regions The current work shows the ionospheric response to an intense geomagnetic storm known as St. Patrick’s Day storm which occurred from 17-22 March 2015 using the ionospheric Chaurasiya, Sunil; Patel, Kalpana; Kumar, Sanjay; Singh, Abhay; Published by: Astrophysics and Space Science Published on: YEAR: 2022   DOI: 10.1007/s10509-022-04137-3 |
This study presents multi-instrument observations of persistent large-scale traveling ionosphere/atmospheric disturbances (LSTIDs/LSTADs) observed during moderately increased auroral electrojet activity and a sudden stratospheric warming in the polar winter hemisphere. The Global Ultraviolet Imager (GUVI), Gravity field and steady-state Ocean Circulation Explorer, Scanning Doppler Imaging Fabry–Perot Interferometers, and the Poker Flat Incoherent Scatter Radar are used to demonstrate the presence of LSTIDs/LSTADs between 1 ... Bossert, Katrina; Paxton, Larry; Matsuo, Tomoko; Goncharenko, Larisa; Kumari, Komal; Conde, Mark; Published by: Geophysical Research Letters Published on: YEAR: 2022   DOI: 10.1029/2022GL099901 |
Nitric Oxide is a very important trace species which plays a significant role acting as a natural thermostat in Earth’s thermosphere during strong geomagnetic activity. In this paper, we present various aspects related to the variation in the NO Infrared radiative flux (IRF) exiting the thermosphere by utilizing the TIMED/SABER (Thermosphere Ionosphere Mesosphere Energetics and Dynamics/ Sounding of the Atmosphere using Broadband Emission Radiometry) observational data during the Halloween storm which occurred in late Octo ... Ranjan, Alok; Krishna, MV; Kumar, Akash; Sarkhel, Sumanta; Bharti, Gaurav; Bender, Stefan; Sinnhuber, Miriam; Published by: Advances in Space Research Published on: YEAR: 2022   DOI: 10.1016/j.asr.2022.07.035 |
They based on the thermospheric O/N 2 density data measured by the global ultraviolet imager (GUVI) onboard the thermosphere, ionosphere, mesosphere energetics, and dynamics ( Published by: Atmosphere Published on: YEAR: 2022   DOI: 10.3390/atmos13030480 |
They based on the thermospheric O/N 2 density data measured by the global ultraviolet imager (GUVI) onboard the thermosphere, ionosphere, mesosphere energetics, and dynamics ( Published by: Atmosphere Published on: YEAR: 2022   DOI: 10.3390/atmos13030480 |
2021 |
The results presented in this paper are obtained from low-latitude ionospheric total electron content (TEC) variation during the chosen geomagnetic storm events happening during the solar cycle 24. We include the four intense geomagnetic storms that occurred on 26 September 2011, 15 July 2012, 19 February 2014 and 20 December 2015, depending upon the availability of TEC data. For this, we have used the TEC data from low-latitude station Varanasi (geographic latitude 25°, 16′N, geographic longitude 82°, 59′E and geomagn ... Singh, Abha; Rathore, Vishnu; Kumar, Sanjay; Rao, S.; Singh, Sudesh; Singh, A.; Published by: Journal of Astrophysics and Astronomy Published on: aug YEAR: 2021   DOI: 10.1007/s12036-021-09774-8 geomagnetic storm; Global positioning system; low latitude; total electron contents |
Statistical Analysis of Throat Aurora Using Long Term DMSP/SSUSI Observation Throat aurora is believed to be associated with magnetopause indentations and has direct implications on magnetopause reconnection. In this study, for the first time, we use Defense Meteorological Satellite Program/Special Sensor Ultraviolet Spectrographic Imager observations over ∼14 years to characterize the throat aurora occurrence, latitudinal extent, seasonal, and its solar cycle dependence. We identified 386 throat aurora cases during the different passes of the satellite over the northern hemisphere. The latitudinal ... Selvakumaran, R.; Han, De-Sheng; Gokani, Sneha; Zhang, Y.; Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2021   DOI: 10.1029/2021JA029164 |
2020 |
Oberheide, J; Pedatella, NM; Gan, Q; Kumari, K; Burns, AG; Eastes, RW; Published by: Geophysical Research Letters Published on: |
The observations of vertical total electron content (VTEC) and L1 and L2 band ionospheric scintillations at an equatorial station, Tarawa (Geomag. Coordinates, 2.68S, 114.26W), Kiribati Kumar, Sushil; Kumar, Sarvesh; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: YEAR: 2020   DOI: 10.1016/j.jastp.2020.105421 |
The observations of vertical total electron content (VTEC) and L1 and L2 band ionospheric scintillations at an equatorial station, Tarawa (Geomag. Coordinates, 2.68S, 114.26W), Kiribati Kumar, Sushil; Kumar, Sarvesh; Published by: Journal of Atmospheric and Solar-Terrestrial Physics Published on: YEAR: 2020   DOI: 10.1016/j.jastp.2020.105421 |
2019 |
In Figure 11, we present an analysis of daily thermospheric O/N 2 data measured by the GUVI onboard the TIMED satellite to see any change in thermospheric O/N 2 composition Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2019   DOI: 10.1029/2018JA025674 |
In Figure 11, we present an analysis of daily thermospheric O/N 2 data measured by the GUVI onboard the TIMED satellite to see any change in thermospheric O/N 2 composition Published by: Journal of Geophysical Research: Space Physics Published on: YEAR: 2019   DOI: 10.1029/2018JA025674 |
2015 |
The effect of geomagnetic storms on low latitude ionosphere has been investigated with the help of Global Positioning System Total Electron Content (GPS-TEC) data. The investigation has been done with the aid of TEC data from the Indian equatorial region, Port Blair (PBR) and equatorial ionization anomaly region, Agartala (AGR). During the geomagnetic storms on 24th April and 15th July 2012, significant enhancement up to 150\% and depression up to 72\% in VTEC is observed in comparison to the normal day variation. The var ... Chakraborty, Monti; Kumar, Sanjay; De, Barin; Guha, Anirban; Published by: Journal of Earth System Science Published on: 07/2015 YEAR: 2015   DOI: 10.1007/s12040-015-0588-3 geomagnetic storm; Ionospheric total electron content; low latitude ionosphere |
2014 |
Limb Viewing Hyper Spectral Imager (LiVHySI) for airglow measurements onboard YOUTHSAT-1
Bisht, R.S.; Hait, A.K.; Babu, P.N.; Sarkar, S.S.; Benerji, A.; Biswas, A.; Saji, A.K.; Samudraiah, D.R.M.; Kirankumar, A.S.; Pant, T.K.; Parimalarangan, T.; Published by: Advances in Space Research Published on: 08/2014 YEAR: 2014   DOI: 10.1016/j.asr.2014.01.016 airglow; Electron density; Ionosphere; Rayleigh; thermosphere; Volume emission |
2013 |
Impacts of atmospheric ultrafast Kelvin waves on radio scintillations in the equatorial ionosphere We present a statistical analysis of the amplitudes of GPS scintillations (S4 index) observed throughout 2008\textendash2010 using the satellite radio occultation measurements of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC). Here, for the first time, periodic variability in the occurrence of S4 is investigated using these data. Significant variations of S4 with periods of 2.5\textendash4 days (quasi-3 days) are identified from the observations during postsunset hours (1900\textendas ... Liu, Guiping; Immel, Thomas; England, Scott; Frey, Harald; Mende, Stephen; Kumar, Karanam; Ramkumar, Geetha; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2013 YEAR: 2013   DOI: 10.1002/jgra.50139 day-to-day variability; Equatorial ionosphere; scintillation; Ultra Fast Kelvin planetary wave |
Impacts of atmospheric ultrafast Kelvin waves on radio scintillations in the equatorial ionosphere We present a statistical analysis of the amplitudes of GPS scintillations (S4 index) observed throughout 2008\textendash2010 using the satellite radio occultation measurements of the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC). Here, for the first time, periodic variability in the occurrence of S4 is investigated using these data. Significant variations of S4 with periods of 2.5\textendash4 days (quasi-3 days) are identified from the observations during postsunset hours (1900\textendas ... Liu, Guiping; Immel, Thomas; England, Scott; Frey, Harald; Mende, Stephen; Kumar, Karanam; Ramkumar, Geetha; Published by: Journal of Geophysical Research: Space Physics Published on: 02/2013 YEAR: 2013   DOI: 10.1002/jgra.50139 day-to-day variability; Equatorial ionosphere; scintillation; Ultra Fast Kelvin planetary wave |
2012 |
GPS-TEC variations during low solar activity period (2007--2009) at Indian low latitude stations The paper is based on the ionospheric variations in terms of vertical total electron content (VTEC) for the low solar activity period from May 2007 to April 2009 based on the analysis of dual frequency signals from the Global Positioning System (GPS) satellites recorded at ground stations Varanasi (Geographic latitude 25\textd ... Kumar, Sanjay; Priyadarshi, S.; Krishna, Gopi; Singh, A.; Published by: Astrophysics and Space Science Published on: 05/2012 YEAR: 2012   DOI: 10.1007/s10509-011-0973-6 geomagnetic storm; GPS; Ionospheric total electron contents; IRI model |
1998 |
Swaminathan, PK; Strobel, DF; Kupperman, DG; Kumar, Krishna; Acton, L; DeMajistre, R; Yee, J-H; Paxton, L; Anderson, DE; Strickland, DJ; , others; Published by: Journal of Geophysical Research: Space Physics Published on: |
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