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Found 16 entries in the Bibliography.
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2022 |
The paper observes the super-imposed effects of intense and moderate solar flares and Coronal Mass Ejection (CME) and High Speed Solar Wind (HSSW) driven geomagnetic storm events on the ionosphere and thermosphere at mid and high latitudes during low solar activity periods. The observations are conducted over a fixed longitude (∼117°W geographic) during May 27–31, 2017 (duration with intense geomagnetic storm without any significant solar flare event), September 3–6, 2017 (duration with solar flare events), September 7–16, 2017 (duration with intense to moderate solar flares as well as geomagnetic storms) and November 28–30, 2020 (duration with a moderate solar flare event with no geomagnetic storm in association). It is found that the effects were the highest during May 27–31, 2017 among all of these events. From the observations of super-imposed effects of the geophysical events, it was found that the effects of an X-class solar flare on September 10–12, 2017 on mid-latitude ionization were suppressed by the Disturbed Dynamo Electric Field (DDEF) from high latitudes during the recovery phase of an intense CME driven geomagnetic storm. The weak effects were also explained by the position of origination of the flare at the Sun. Correlations were observed between the variations in O/N2, neutral wind velocities and the mid and high latitude Total Electron Content (TEC) during these periods. Possible explanation is given for those few cases (for example, September 14, 2017) when the variations in O/N2 mismatched with the local TEC especially in the mid-latitudes. The effects of the solar flare event on November 28–30, 2020 which were short-lived have also been also observed at locations near the subsolar point from low latitudes in the southern hemisphere. Sur, Dibyendu; Ray, Sarbani; Paul, Ashik; Published by: Advances in Space Research Published on: jul YEAR: 2022   DOI: 10.1016/j.asr.2022.04.024 CME driven storms; HSSW driven storms; Joule heating; O/N ratio; Plasmaspheric contributions; Solar flare |
In this study, we investigate the negative ionospheric response over the European sector during two storms that took place on 8 September 2017, primarily, by exploiting observations over ten European locations. The spatial and temporal variations of TEC, foF2 and hmF2 ionospheric characteristics are examined with the aim to explain the physical mechanisms underlying the strong negative ionospheric response. We detected very sharp electron density (in terms of foF2 and TEC) decrease during the main phases of the two storms and we attributed this phenomenon to the large displacement of the Midlatitude Ionospheric Trough (MIT). Our study also revealed that the two storms show different features caused by different processes. In addition, Large Scale Traveling Ionospheric Disturbances (LSTIDs) were observed during both storms, followed by enhanced Spread F conditions over Digisonde stations. The regional dependence of ionospheric storm effects was demonstrated, as the behavior of ionospheric effects over the northern part of Europe differed from that over the southern part. Oikonomou, Christina; Haralambous, Haris; Paul, Ashik; Ray, Sarbany; Alfonsi, Lucilla; Cesaroni, Claudio; Sur, Dibyendu; Published by: Advances in Space Research Published on: aug YEAR: 2022   DOI: 10.1016/j.asr.2022.05.035 Large-scale traveling ionospheric disturbances; Mid-latitude ionospheric trough; September 2017 geomagnetic storm; Swarm satellite |
2021 |
The present paper reports magnetospheric-thermospheric-ionospheric interactions, observed during geomagnetically disturbed periods in 2015–2016 from mid-latitude stations located in the US-Pacific longitudes (\textasciitilde120°W geographic). These interactions have been analyzed for a series of Coronal Mass Ejection (CME) and High Speed Solar Wind (HSSW) driven geomagnetic storms during the moderate solar activity periods. The geomagnetically disturbed periods under consideration in this paper have an interesting feature of the occurrences of one or more HSSW events following an intense CME driven intense geomagnetic storm. Correlations were observed between the solar and geomagnetic parameters, hemispherically integrated Joule heating, changes in O/N2 ratio, corresponding changes in neutral wind velocities and mid-latitude Vertical Total Electron Content (VTEC) in most of the cases. Prolonged effects of neutral wind driven equatorward plasma transport process were noticed during the period of the summer solstice (June 23–26, 2015) which was correlated with the hemispherically integrated Joule heating and ionospheric conductivities. The effects of storm onset were observed during March 17–18, 2015. The influences of the ‘super-fountain effect’ in terms of Prompt Penetration Electric Field (PPEF) were seen during the main phases of the geomagnetic storms from these mid-latitude stations. This is correlated with the strength of Equatorial Electrojet (EEJ). Sur, Dibyendu; Ray, Sarbani; Paul, Ashik; Published by: Advances in Space Research Published on: aug YEAR: 2021   DOI: 10.1016/j.asr.2021.03.027 CME and HSSW storms; Joule heating; Meridional and zonal wind; O/N ratio; Plasma transport; VTEC |
Carter, Jennifer; Samsonov, AA; Milan, Stephen; Branduardi-Raymont, Graziella; Ridley, Aaron; Paxton, Larry; Anderson, Brian; Waters, Colin; Edwards, Thomas; Published by: Journal of Geophysical Research: Space Physics Published on: |
Carter, Jennifer; Samsonov, Andrey; Milan, Stephen; Branduardi-Raymont, Graziella; Ridley, Aaron; Paxton, Larry; Anderson, Brian; Waters, Colin; Edwards, Thomas; Published by: Earth and Space Science Open Archive ESSOAr Published on: |
2020 |
Chakraborty, Sumanjit; Ray, Sarbani; Sur, Dibyendu; Datta, Abhirup; Paul, Ashik; Published by: Advances in Space Research Published on: |
2019 |
This paper presents the response of the ionosphere during the intense geomagnetic storms of October 12\textendash20, 2016 and May 26\textendash31, 2017 which occurred during the declining phase of the solar cycle 24. Total Electron Content (TEC) from GPS measured at Indore, Calcutta and Siliguri having geomagnetic dips varying from 32.23\textdegreeN, 32\textdegreeN and 39.49\textdegreeN respectively and at the International GNSS Service (IGS) stations at Lucknow (beyond anomaly crest), Hyderabad (between geomagnetic equator and northern crest of EIA) and Bangalore (near magnetic equator) in the Indian longitude zone have been used for the storms. Prominent peaks in diurnal maximum in excess of 20\textendash45 TECU over the quiet time values were observed during the October 2016 storm at Lucknow, Indore, Hyderabad, Bangalore and 10\textendash20 TECU for the May 2017 storm at Siliguri, Indore, Calcutta and Hyderabad. The GUVI images onboard TIMED spacecraft that measures the thermospheric O/N2 ratio, showed high values (O/N2 ratio of about 0.7) on October 16 when positive storm effects were observed compared to the other days during the storm period. The observed features have been explained in terms of the O/N2 ratio increase in the equatorial thermosphere, CIR-induced High Speed Solar Wind (HSSW) event for the October 2016 storm. The TEC enhancement has also been explained in terms of the Auroral Electrojet (AE), neutral wind values obtained from the Horizontal Wind Model (HWM14) and equatorial electrojet strength from magnetometer data for both October 2016 and May 2017 storms. These results are one of the first to be reported from the Indian longitude sector on influence of CME- and CIR-driven geomagnetic storms on TEC during the declining phase of solar cycle 24. Chakraborty, S.; Ray, S.; Sur, D.; Datta, A.; Paul, A.; Published by: Advances in Space Research Published on: 10/2019 YEAR: 2019   DOI: 10.1016/j.asr.2019.09.047 |
It has already been established that during the main phase and recovery phase of any geomagnetic storm, thermospheric O/N2 column density ratio decreases in the high latitudes Sur, Dibyendu; Ray, Sarbani; Paul, Ashik; Published by: Published on: |
2012 |
This paper presents remotely sensed neutral temperatures obtained from ultraviolet observations and compares them with temperatures from the NRLMSISE-00 version of the Mass Spectrometer and Incoherent Scatter (MSIS) model (unconstrained and constrained to match the total densities from satellite drag). Latitudinal profiles of the temperatures in the Earth\textquoterights thermosphere are obtained by inversion of high-resolution (\~1.3\ \r A) observations of the (1,1) and (5,4) Lyman-Birge-Hopfield (LBH) bands of N2. The spectra are from the High resolution Ionospheric and Thermospheric Spectrograph (HITS) instrument aboard the Advanced Research and Global Observation Satellite (ARGOS). The results indicate that on each day examined there was consistency between the remotely sensed thermospheric temperatures, the densities from coincident satellite drag measurements at adjacent altitudes, and the NRLMSISE-00 model. Krywonos, Andrey; Murray, D.; Eastes, R.; Aksnes, A.; Budzien, S.; Daniell, R.; Published by: Journal of Geophysical Research Published on: 09/2012 YEAR: 2012   DOI: 10.1029/2011JA017226 airglow; N2; remote sensing; satellite drag; temperature; thermosphere |
2011 |
Modeled and observed N 2 Lyman-Birge-Hopfield band emissions: A comparison Eastes, R.; Murray, D.; Aksnes, A.; Budzien, S.; Daniell, R.; Krywonos, A.; Published by: Journal of Geophysical Research Published on: Jan-01-2011 YEAR: 2011   DOI: 10.1029/2010JA016417 |
Modeled and observed N2 Lyman-Birge-Hopfield band emissions: A comparison Eastes, RW; Murray, DJ; Aksnes, A; Budzien, SA; Daniell, RE; Krywonos, A; Published by: Journal of Geophysical Research: Space Physics Published on: |
2009 |
Basu, Su.; Basu, S.; Huba, J.; Krall, J.; McDonald, S.; Makela, J.; Miller, E.; Ray, S.; Groves, K.; Published by: Journal of Geophysical Research Published on: Jan-01-2009 YEAR: 2009   DOI: 10.1029/2008JA013899 |
2008 |
Hecht, JH; Mulligan, T; Strickland, DJ; Kochenash, AJ; Murayama, Y; Tanaka, Y-M; Evans, DS; Conde, MG; Donovan, EF; Rich, FJ; , others; Published by: Journal of Geophysical Research: Space Physics Published on: |
Ultraviolet (UV) spectra obtained from Earth s dayglow contain important information for understanding the thermosphere, and the N 2 Lyman-Birge-Hopfield (LBH) bands are possibly Published by: Published on: |
2007 |
Basu, S; Huba, J; Makela, J; Ray, S; Groves, K; Published by: Published on: |
2006 |
Basu, S; Makela, J; Miller, E; Dasgupta, AK; Ray, S; Groves, K; Rich, FJ; Published by: Published on: |
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