Peculiarities of 630.0 and 557.7 nm emissions in the main ionospheric trough: March 17, 2015

Abstract

Peculiarities of 557.7 and 630.0 nm emissions observed in the second step of the magnetic storm main phase at the mid-latitude observatory Tory (52° N, 103° E) on March 17, 2015 are compared with the changes in ionospheric parameters above this station, detected from ionospheric sounding data and total electron content maps. We have found that the intensity of the 557.7 and 630.0 nm emissions noticeably increased after the observatory entered into the longitudinal sector of the developed main ionospheric trough (MIT). The most powerful synchronous increases in intensities of the two emissions are associated with amplification of the westward electrojet during strengthening of the magnetospheric convection. We study the dependence of the ratios between the intensities of 630.0 nm emission recorded in the north, zenith, and south directions on the position of emitting regions relative to the MIT bottom. The SAR arc is shown to appear initially near the bottom of the MIT polar wall and approach the zenith of the station during registration of F3s reflections by an ionosonde, which indicate the presence of a polarization jet near the observation point.

Spatial and Temporal Confinement of the Ionospheric Responses During the St. Patrick's Day Storm of March 2015

“…Our results (Figure 4) not only match with the above, but also Similarly, the result of some other studies concerning the longitude sector of −20°E−150°E have shown marked differences in the Joule heating between nearby longitudes on 17 and 18 March. For example, in the Russian sector, the nearby longitudes have exhibited significant differences among the multi-scale optical (Zolotukhina et al, 2021) and radio signatures of auroral irregularities (Zakharenkova et al, 2018;Zolotukhina et al, 2017) during 12-23 UT on 17 March. Also, a comparative study by Lu et al (2020) has reported longitudinal differences in the Joule heating and the VTEC perturbations using TIE-GCM simulations on 17 and 18 March 2015.…”