[P-EM11] Coupling Processes in the Atmosphere-Ionosphere System

[PEM11-07] Ionospheric plasma irregularities and GPS scintillation/outage observed by Swarm and other LEO satellites

★Invited Papers

*Chao Xiong^1,3、Xin Wan²、Claudia Stolle³、Yiwen Liu⁴、Jisheng Xu¹ (1.Department of Space Physics, College of Electronic and Information, Wuhan University, 430072 Wuhan, China、2.Planetary Environmental and Astrobiological Research Laboratory (PEARL), School of Atmospheric Sciences, Sun Yat-sen Univeristy, Zhuhai, China、3.GFZ German Research Centre for Geosciences, Telegrafenberg, 14473, Potsdam, Germany、4.Scholl of Physics and Electronic Information, Shangrao Normal University, Shangrao, China)

キーワード：Ionospheric plasma irregularities, Scintillation, Ionosphere-Theremosphere coupling, GNSS, Swarm, LEO satellites

Ionospheric plasma irregularities are an important issue for the ionospheric and Global Navigation Satellite System (GNSS) related communities. The generation as well as the global distribution of irregularities are highly related to ionospheric and ionosphere-thermosphere coupling processes. This talk will review recent results on plasma irregularities observed by ESA’s Swarm mission. The characteristics of irregularities detected by in-situ plasma density and related GNSS measurements from Swarm are consistent with previous findings. However, with three satellites forming a constellation, Swarm provides new insights about plasma irregularities, e.g., their scale lengths, that cannot be achieved by single satellite mission. For example, when the Swarm satellites cross the plasma irregularities, the GNSS measurements show only intense carrier phase variations but almost no amplitude fades (less than 2 dB-Hz), both characterizing GNSS scintillation behaviors. These observations are different from what we learn from data of ground-based receivers. Further comparisons with GNSS data received at the GOCE satellite, which flew at about 250 km, we found that the Fresnel diffractive process is necessary to cause GPS signal amplitude fades during scintillations. Swarm observations also reveal that the absolute density gradient associated with plasma irregularities is an important parameter for causing the outage of spaceborne GNSS receiver.