Bibliography

Distinct ionospheric response to three different geomagnetic storms during 2016 using GPS-TEC observations over the Indian equatorial and low latitude sectors

The ionospheric response during three distinct geomagnetic storms occurred in the year 2016 is investigated using GPS-TEC observations in the Indian equatorial and low latitude sectors. The three geomagnetic storms are considered for this study which were occurred on 20 January 2016 (2230 LT), 6 March 2016 (0230 LT) and 13 October 2016 (0530 LT) with minimum Sym-H values of −95 nT, −110 nT and −114 nT respectively. These three geomagnetic storms are different from one another in the sustainment of main and recovery phases and are occurred at three different local times corresponding to the Indian longitudes. This study brings out the major differences of these three geomagnetic storms characteristics and their distinct effects on the equatorial and low latitude ionosphere. Significant changes in the VTEC during main and recovery phases of these three storms are found to be mainly associated with prompt penetration electric fields and thermospheric neutral compositional changes. During the storm of 20 January 2016, positive storm effects during main and recovery phases of the storm are in association with the penetration electric fields. The complete main phase for the 6 March 2016 geomagnetic storm was occurred during night time and no changes in VTEC has been identified, which could be due to the weak background electron density. A positive storm effect is noticed during the recovery phases of the storms of 6 March 2016 and 13 October 2016, due to the storm induced electric fields differences and in particular due to the enhanced [O]/[N2] ratio in thermospheric composition. A strong positive storm effect caused by Co-rotating Interacting Region (CIR) induced disturbances after the 13 October 2016 storm is also discussed.

Lissa, D.; Venkatesh, K.; Prasad, D.; Niranjan, K.;

Published by: Advances in Space Research      Published on: aug

YEAR: 2022     DOI: 10.1016/j.asr.2022.05.027

Disturbance Dynamo; Geomagnetic storms; Positive Storm Effect; Prompt Penetration Electric Fields (PPEF); Total electron content (TEC)

Spatial and temporal confinement of the ionospheric responses during the St. Patrick s Day storm of March 2015

The present study provides a multi‐instrument analysis of the ionospheric response to the effects of the St. Patrick s Day storm of 17–18 March 2015. Simultaneous observations from 85

Kader, Sk; Dashora, N; Niranjan, K;

Published by: Space Weather      Published on:

YEAR: 2022     DOI: 10.1029/2022SW003157

Ionospheric response to the 26 August 2018 geomagnetic storm using GPS-TEC observations along 80 E and 120 E longitudes in the Asian sector

Lissa, D; Srinivasu, VKD; Prasad, DSVVD; Niranjan, K;

Published by: Advances in Space Research      Published on:

YEAR: 2020     DOI:

L-band scintillation and TEC variations on St. Patrick’s Day storm of 17 March 2015 over Indian longitudes using GPS and GLONASS observations

The aim of the present study is to investigate the response of ionospheric total electron content (TEC), Global Positioning System (GPS) and Global Navigation Satellite System (GLONASS) scintillations during 17 March 2015 St. Patrick\textquoterights Day geomagnetic storm over Visakhapatnam, which is popularly known as Waltair (WALT) in the literature. GPS TEC observations obtained from five IGS stations (SGOC, IISC, HYDE, LCK4 and LHAZ) and WALT during the storm have been compared. The TEC derived from GPS, GLONASS constellations and CODE global ionosphere TEC map (GIM) over WALT has also been compared. Positive storm effect during the main phase of the storm and negative storm effect during the recovery phase of the storm were observed over the said stations. The variation of northern equatorial ionisation anomaly TEC (CODE GIM TEC maps) in response to the St. Patrick\textquoterights Day storm over four Indian longitudes (75oE, 80oE, 85oE and 90oE) has also been presented. Strong amplitude and phase scintillations were observed in the L-band signals of GPS and GLONASS constellations over WALT. Twelve satellite (Pseudo Random Noise) PRNs of GPS L1 and nine PRNs of each GLONASS L1 and L2-band signals were affected by strong amplitude and phase scintillation. The peak amplitude scintillation index (S4) obtained from the effected PRNs of GPS L1 signal and GLONASS L1-band signals over WALT range from 0.36 to 0.74 and 0.36 to 0.76, respectively. Strong fluctuations in rate of TEC index are noted over the said stations. This enhanced scintillation activity is mainly due to the main phase of the storm falls in the evening sector over the Indian region.

Srinivasu, K; Prasad, D; Niranjan, K; Seemala, Gopi; Venkatesh, K;

Published by: Journal of Earth System Science      Published on: 03/2019

YEAR: 2019     DOI: 10.1007/s12040-019-1097-6