Rapid changes in depolarization due to thunderclouds obtained from the CS-3 beacon signal observation

In August and September 1990, several ice depolarization events associated with summertime thunderclouds were observed at the CSK Osaka earth station using the CS-3 beacon signal (19.45 GHz, RHCP, EL=49.5 degrees ). The observation of the CS-3 beacon signal has revealed characteristic changes in XPD (cross-polarization discrimination) and cross-polar phase caused by high-altitude ice crystals in thunderclouds. In light of recent thunderstorm electrification theory and other thundercloud observations, these kinds of rapid changes are related to the intercloud discharge near the cloud top, which does not necessarily correspond to the lightning flashes seen on the ground. The impact of thunderstorm events upon dual-polarization satellite communication links using linear horizontal and vertical polarizations is considered.<>