[P-EM16] Coupling Processes in the Atmosphere-Ionosphere System

10:00 AM - 10:15 AM JST(1:00 AM - 1:15 AM UTC)

[PEM16-17] Ionospheric disturbances due to the Kamchatka Earthquake (July 2025) observed by the SuperDARN radars

*Nozomu Nishitani¹, Tomoaki Hori¹, Atsuki Shinbori¹, Pasha Ponomarenko^1,2 (1.Institute for Space-Earth Environmental Research, Nagoya University, 2.University of Saskatchewan)

Keywords:

SuperDARN Hokkaido Pair of (HOP) radars,coseismic ionospheric disturbances,Kamchatka Earthquake,stereomode operation

On July 22, 2025, a giant earthquake (Mw=8.8) occurred off the eastern coast of the Kamchatka Peninsula. The initial disturbance at the epicenter began at 2324 UT. The SuperDARN Hokkaido Pair of (HOP) radars, located in Hokkaido and operated by ISEE, Nagoya University, began monitoring the coseismic ionospheric disturbances at 2336 UT. In particular, the SuperDARN Hokkaido West HKW) radar was operating with ‘stereoscan’ mode, with channel A scanning through the whole field of view with a 1-minute interval, and channel B monitoring the fixed beam direction (beam 10) every 3 seconds. In addition, channel A was scanning from west to east, in the opposite direction to the propagation of the disturbances, so that it was possible to determine the point of intersection of the scanning beam with the disturbance with an accuracy of 3 seconds. Moreover, since channels A and B operate at different radar frequencies (10.81 MHz vs 9.15 MHz), it is possible to discuss the vertical and horizontal propagation speeds of the disturbance. Initial results of the analysis of this event, and the preliminary interpretation of the propagation characteristics of the coseismic ionospheric disturbance, will be presented.