Bibliography

FUV observations of variations in thermospheric composition and topside ionospheric density during the November 2004 magnetic superstorm

We revisited the November 2004 superstorm by analyzing TIMED/GUVI data. The 135.6 nm limb radiances at 520-km are mainly due to the O+ and electron radiative recombination and represent the daytime ionosphere density at the altitude. The 135.6 nm radiances clearly showed a signature of ionospheric equatorial arcs and their variations during the November 2004 magnetic superstorm. When an intense eastward Interplanetary Electric Field (IEF) occurred, the dayside equatorial arcs were enhanced and their latitude separation increased. The enhanced equatorial arcs were hemispherically symmetric or asymmetric in the region with non-depleted O/N2 or hemispherically asymmetric O/N2 depletion, respectively. When O/N2 depletion reached the magnetic equator, there was no observable enhancement in the equatorial arcs regardless the IEF conditions, indicating O/N2 condition significantly modulated the variations in storm-time equatorial arcs. GUVI observations also showed that a westward IEF and/or disturbance dynamo electric field could also suppress the dayside equatorial arcs.

Zhang, Yongliang; Paxton, LarryJ.; Huang, Chaosong; Wang, Wenbin;

Published by: Journal of Atmospheric and Solar-Terrestrial Physics      Published on: feb

YEAR: 2022     DOI: 10.1016/j.jastp.2022.105832

geomagnetic storm; penetration electric field; Thermosperic composition; topside ionosphere

Low-Latitude Zonal Ion Drifts and Their Relationship With Subauroral Polarization Streams and Auroral Return Flows During Intense Magnetic Storms

We analyze horizontal plasma drifts measured by the Defense Meteorological Satellite Program satellites during two intense magnetic storms. It is found, for the first time, that westward plasma flows associated with subauroral polarization streams (SAPS) in the dusk-evening sector penetrate continuously to equatorial latitudes. The westward ion drifts between subauroral and equatorial latitudes occur nearly simultaneously. The latitudinal profile of the westward ion drifts at low latitudes (approximately within ±30° magnetic latitude [MLat]) is relatively flat, and the westward ion drifts at the magnetic equator reach 200–300 m s−1. In the dawn-morning sector, eastward ion drifts at subauroral latitudes are also SAPS. The storm-time dawnside auroral boundary moves to ∼±55° MLat, and the dawnside SAPS penetrate to ∼±20° MLat at 0930 local time. A dawnside SAPS flow channel appears to exist, although it is not as well defined as the duskside SAPS flow channel. Thermospheric wind data measured by the Challenging Minisatellite Payload satellite are analyzed, and zonal disturbance winds are derived. Disturbance winds can reach equatorial latitudes rapidly near midnight but are limited to ±40° geographic latitude or higher near noon. The effects of disturbance winds on the zonal ion drifts at middle and low latitudes are discussed. It is suggested that both the westward ion drifts at middle and low latitudes in the dusk-evening sector and the eastward ion drifts at middle and lower latitudes in the dawn-morning sector are caused primarily by penetration of the SAPS and auroral electric fields.

Huang, Chao-Song; Zhang, Yongliang; Wang, Wenbin; Lin, Dong; Wu, Qian;

Published by: Journal of Geophysical Research: Space Physics      Published on:

YEAR: 2021     DOI: 10.1029/2021JA030001

Electric field; Ionosphere; ionospheric plasma drift; penetration electric field; Subauroral Polarization Streams; thermospheric wind