Seasonal Characteristics of Precipitation in 1998 over East Asia as Derived from TRMM PR

Precipitation radar data derived from the Tropical Rainfall Measuring Mission (TRMM) satelliteare used to study precipitation characteristics in 1998 over East Asia (10°-38°N, 100°-145°E), especiallyover mid-latitude land (continental land) and ocean (East China Sea and South China Sea). Results arecompared with precipitations in the tropics. Yearly statistics show dominant stratiform rain events overEast Asia (about 83.7% by area fraction) contributing to 50% of the total precipitation. Deep convectiverains contribute 48% to the total precipitation with a 13.7% area fraction. The statistics also show theunimportance of warm convective rain in East Asia, contributing 1.5% to the total precipitation with a2.7% area fraction. On a seasonal scale, the results indicate that the rainfall ratio of stratiform rain todeep convective rain is proportional to their rainfall pixel ratio. Seasonal precipitation patterns comparewell between Global Precipitation Climatology Project rainfall and TRMM PR measurements except insummer. Studies indicate a clear opposite shift of rainfall amount and events between deep convective andstratiform rains in the meridional in East Asia, which corresponds to the alternative activities of summermonsoon and winter monsoon in the region. The vertical structures of precipitation also exhibit strongseasonal variability in precipitation Contoured Rainrate by Altitude Diagrams (CRADs) and mean profilesin the mid-latitudes of East Asia. However, these structures in the South China Sea are of a tropical typeexcept in winter. The analysis of CRADs reveals a wide range of surface rainfall rates for most deepconvective rains, especially in the continental land, and light rain rate for most stratiform rains in EastAsia, regardless of over land or ocean.