Response of the Asian-Australian Low Latitude TEC to the 2013 SSW Event and a Moderate Geomagnetic Storm.

In this study, the Total Electron Content (TEC) variability over Asian-Australian low-latitude sector is investigated during the 2013 Sudden Stratospheric Warming (SSW) event that overlapped with a moderate geomagnetic storm. These investigations are about the latitudinal distribution of ionospheric TEC measured from 10 Global Positioning System (GPS) receivers along 115° E in the Asian-Australian sector. We used a pair of magnetometers to reveal the equatorial electrojet (EEJ) strength equivalent to the magnetometer-inferred drift. Also, the NASA Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED) satellite airglow instrument was used to unveil the changes in the neutral thermospheric ratio during the event. The current work was compared with a similar investigation in the American sector. During SSW onset (7 January 2013), the northern EIA crest that moved poleward in the Asian-Australian sector contradicted the equatorward movement of the crest observed in the American sector. At both the Asian-Australian and American longitudes in mid-January, the poleward northern crests are at higher latitudes in the American longitude than in the Asian-Australian longitude. This longitudinal difference in mid-January was evident in significant enhancement of the magnetometer inferred upward-directed drift in the American sector compared to the Asian-Australian sector. Compared to the American sector, the moderate geomagnetic storm that overlapped the ongoing major SSW on 17 January 2013 did not significantly affect the Asian-Australian sector. The storm-time effect on the TEC on 18 January 2013 in the Asian-Australian sector reduced (increased) the SSW (photo-ionization) effect in the northern (southern) hemisphere. [ABSTRACT FROM AUTHOR]