Interannual variability of summer monsoon convective and stratiform precipitations in East Asia during 1998–2013

Abstract

ABSTRACTIn this paper, interannual variations of convective and stratiform precipitations in summer East Asian monsoon (SEAM) dominion are analysed using 16‐year (1998–2013) Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) rain products (2A25 and 3A25). It is found that the climatological mean patterns of convective and stratiform rain rates (RRs) are generally similar to each other, but the area fraction (AF) of stratiform precipitation can always reach about 80% and dominates in summer East Asia. Nonetheless, convective precipitation produces similar rainfall quantity with stratiform rainfall. For the RR, AF and contribution fraction (CF), their interannual standard deviation and coefficient of variation (CV) spatial patterns are similar between summer convective and stratiform precipitations in East Asia, because of the fact that they are all maybe influenced by SEAM. Differently, only the intensity of interannual variability (i.e. CV) for convective precipitation AF is much greater than that for stratiform precipitation, while CV for both convective and stratiform precipitations RR/CF are similar in most areas. Moreover, the interannual variability of SEAM is more highly correlated with that of RR for convective precipitation than that for stratiform precipitation in most land regions. While the opposite conclusion is found in ocean regions. Generally, the SEAM intensity in the lower troposphere mainly controls interannual variability of the atmospheric stability and both stratiform and convective precipitations RR. Then, atmospheric stability variation further modulates the AF and CF variations of both stratiform and convective precipitations on the interannual scale. This work mainly provides possible evidence of linkage between large‐scale circulation and convective and stratiform precipitations on the interannual scale. It suggests that the possible dominant mechanism should be explored using more observations and together with model simulations in the future work.