[M-TT43_1PM2] Brand-new scope of coupling geophysics being established by infrasound and associated waves

[MTT43-04] Micro-barometric variation associated with rainfall

Toshihiko IYEMORI¹, *Yasuharu SANO², Taiichi HAYASHI³, Yoko ODAGI¹, Tadashi AOYAMA¹, Kunihito NAKANISHI¹ (1.Graduate School of Science, Kyoto University, 2.Asahi University, 3.DPRI, Kyoto University)

Keywords:micro-barometric variation, gravity wave, rainfall, acoustic gravity wave

A sudden rainfall (shower) is often preceded by a micro-barometric variation. To examine quantitative relationships between them, we conducted observations of micro-barometric, rainfall and absorption of BS broadcasting radio waves and recorded the data with one second resolution.As a result, we often observed the events where a pressure increase starts about one minute before a strong rainfall. Just after the start of the rainfall, micro-barometric variation with period about a few minutes were also observed. These results suggest that the dynamic pressure associated with the falling rain drops pushes the air and observed as a gradual increase of the pressure on the ground. If this is the case, a rarefaction waves may propagate upward over the rain cloud. In this paper, we will show the results obtained from many events.