Barrier layer in the northeastern South China Sea and its formation mechanism

Robust evidence for the barrier layer (BL) in the northeastern South China Sea (SCS) (16°–25°N, 112°–124°E) is presented. The occurrence rate of the BL peaks in the autumn (45.7%) and then the summer (31.1%) and the spring (23.3%), sequently. It is estimated that the annual occurrence rate of the BL reaches about 40.0% in the central northeastern SCS (18°–22°N, 112°–120°E) and the Luzon Strait. Stratification-formed (Rain-formed) mechanism is the major factor responsible for the occurrence of the BL in the northeastern SCS in the spring (the summer and autumn), respectively. The rainfall observation from TRMM provides reliable evidence for the latter.