14:00 〜 14:15
[PEM14-14] Equatorial Plasma Bubble detected by L-Band Synthetic Aperture Radar and GNSS-TEC Observations in Indonesian Region
キーワード：EPB, ROTI map, L-Band SAR, ALOS-2/PALSAR-2
Equatorial Plasma Bubbles (EPBs) are disturbances in the ionosphere occurring close to the magnetic equator. These bubbles typically form after sunset during equinox months, though they can also be observed in other seasons. This phenomenon causes significant interference with radio wave signals, which are crucial for communication and navigation systems. We first search for plasma bubble occurrences in Indonesia, South-East Asian Sectors, by scanning through ROTI map available from https://gatotkaca.brin.go.id/petaionosfer/ionosphericmap/. ROTI map on May 9th, 2024 shows massive EPB clusters in Indonesia, one day prior to severe geomagnetic storm on May 10th, 2024. We further studied the small-scale structure of this EPB occurrence in Kalimantan (Indonesia) on May 9th, when ALOS-2/PALSAR-2 acquisition track overlaps the high-index of ROTI map at 23:39 local time (LT). ALOS-2/PALSAR-2 is L-band Synthetic Aperture Radar (SAR) sensor, whose images allowed us to perform azimuth offset tracking method; we concatenated two consecutive frames of ascending SAR images to expand the spatial coverage. It is notable that typical NE-SW azimuth streaking offset, exceeding 20 meters, has been observed, whose orientations are likely due to the ambient of geomagnetic field-line. The Total Electron Content (TEC) depletion associated with plasma bubble from SAR images are also measured in a range of 5-10 TECU. This amplitude is consistent with TEC depletion observed in GNSS-TEC.