*Randi Firdaus^1,2、Toshio Suga^1,3 (1.Department of Geophysics, Graduate School of Science, Tohoku University, Sendai, Japan、2.Indonesian Agency for Meteorology Climatology and Geophysics (BMKG), Jakarta, Indonesia、3.Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), Tohoku University, Sendai, Japan)