[P-EM14] [EE] Dynamics in magnetosphere and ionosphere

[PEM14-P15] Global mapping of ionospheric plasma velocity distributions using spherical elementary current systems based on SuperDARN data

*Shin'ya Nakano¹, Tomoaki Hori², Kanako Seki², Nozomu Nishitani³ (1.The Institute of Statistical Mathematics, 2.Graduate School of Science, the University of Tokyo, 3.Institute of Space-Earth Environmental Research, Nagoya University)

Keywords:ionospheric convection, SuperDARN, spherical elementary current systems

We have developed a method for estimating the global distribution of ionospheric plasma velocity from the SuperDARN data. The SuperDARN observations have a wide spatial coverage. However, it is difficult to obtain a global ionospheric convection map from the SuperDARN data because individual radars give only line-of-sight components of plasma drift velocity and the data are frequently missing. In our technique, the plasma velocity distribution is represented by a sum of divergence-free spherical elementary current systems, which provides a constraint ensuring the divergence free condition. In this paper, we will demonstrate a preliminary results obtained by our newly developed method.