TY  - JOUR
A1  - Luo, Xiaomin
A1  - Xiong, Chao
A1  - Gu, Shengfeng
A1  - Lou, Yidong
A1  - Stolle, Claudia
A1  - Wan, Xin
A1  - Liu, Kangkang
A1  - Song, Weiwei
T1  - Geomagnetically conjugate observations of equatorial plasma irregularities from swarm constellation and ground-based GPS stations
JF  - Journal of geophysical research: Space physics
N2  - The near-polar orbit satellites of Swarm mission provide a good opportunity to investigate the conjugacy of equatorial plasma irregularities (EPIs) since their trajectories at low latitudes are basically aligned with fixed geographical longitude. However, the Swarm in situ electron density occasionally shows EPIs at only one hemisphere at this longitude. In this study, we provide detailed analysis of such EPI events from the in situ electron densities and onboard global positioning system (GPS) measurements of Swarm low pair satellites, and simultaneous GPS data from two geomagnetically conjugate ground stations at the Africa longitudes. The result indicates that when Swam in situ electron density sometime shows EPIs at only one hemisphere, the GPS scintillations are still observed from the Swarm onboard receiver and by the two conjugate ground stations. It implies that the EPIs should generally elongate along the geomagnetic flux tube. More than two-year statistic results show that the onset time of scintillation in the northern station is on average 16 and 18 min earlier than that in the southern station for September equinox and December solstice in 2015, while for March equinox in 2016 the onset time of scintillation of northern station is about 11 min later than that of southern station, which indicates the asymmetry features of EPIs along the flux tube. Further analysis of nearly three-year GPS data from two conjugate stations at the Asia longitudes, we find that during solar maximum years the local sunset time plays an important role for causing the difference of onset time of scintillation between two conjugate stations.
Y1  - 2019
U6  - https://doi.org/10.1029/2019JA026515
SN  - 2169-9380
SN  - 2169-9402
VL  - 124
IS  - 5
SP  - 3650
EP  - 3665
PB  - Wiley
CY  - Hoboken
ER  -