Study on Climatological Characteristics of rainfall induced by tropical cyclones using the satellite observations

The climatological characteristics of rainfall induced by tropical cyclone over the western North Pacific are examined using the satellite observation. The Tropical Rainfall Measuring Mission (TRMM) 3B42 provides invaluable rainfall data for tropical cyclone (TC) research since 1998. Based on TRMM 3B42 data, rainfall properties of TCs are statistically quantified for different sea surface temperature (SST) levels and TC intensities. As TCs are stronger, the TC-induce rainfalls increase about 15% per 20 knot of TC’s wind speed. The rainfall induced by TC also increases as the SST warming. The increase rate is about 8-10 % per 1 ℃of SST. The rate is comparable to the idealized environmental water vapor content changes obtained by multiplying the average SST change by 7% per 1 °C. The changes in TC-induced rainfall related to both TC intensity and SST also show consistent results, suggesting that both TC intensity and SST are main factors for the changes in TC-induced rainfall.