Li, Z., Y. Luo, Y. Du, and J. C. L. Chan, 2020: Statistical characteristics of pre-summer rainfall over South China and associated synoptic conditions. J. Meteor. Soc. Japan, 98,
Early Online Release Graphical Abstract with highlights
Plain Language Summary: After the South China Sea (SCS) monsoon onset, an increase in domain-averaged rainfall accumulation and a generally enhanced convective intensity over South China (SC) during Apr-Jun were previously noticed. This study comparatively examines the characteristics of rainfall over the west-inland, east-inland, and coastal regions of SC during pre- and post-monsoon onset periods, and discuss the associated synoptic conditions and physical mechanisms.
- After the monsoon onset, accumulated rainfall amounts increase over the west-inland and coastal regions, whereas remain nearly unchanged in the east-inland region due to its enhanced intensity but fewer occurrences of rainfall.
- Favorable dynamic instability and thermodynamic conditions for the inland rainfall result from collective effects of a subtropical low pressure/front/shearline and southwesterly air flow of tropical origin.
- The deceleration of the southerly BL flow over the northern SCS leads to convergence of BL high-θe air near the coast, which is a key factor in producing the coastal, warm-sector rainfall. However, heavy rainfall could occur near the coast even the southerly air flows in the BL and lower troposphere are too weak to be considered as jets.