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 summ...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%), se-quently. 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.展开更多
Mesoscale eddy effects on the wintertime verti-cal mixing in the formation region of the North Pacific Sub-tropical Mode Water (NPSTMW) are studied using hydro-graphic data from Argo profiling floats deployed in the K...Mesoscale eddy effects on the wintertime verti-cal mixing in the formation region of the North Pacific Sub-tropical Mode Water (NPSTMW) are studied using hydro-graphic data from Argo profiling floats deployed in the Ku-roshio recirculation region in February and March of 2001. Anticyclonic (warm) eddy enhances the wintertime vertical mixing and results in the deep mixed layer and the deep thermocline. Consequently, a large volumetric water mass with low potential vorticity corresponding to the prototype of NPSTMW tends to be formed. By contrast, cyclonic (cold) eddy is unfavorable for the vertical mixing process and halts the deepening of the mixed layer and thus the formation of mode water. Further analysis shows that cyclonic eddies prevail in the late 1990s in the formation region of NPSTMW, which lead to significant suppression of the wintertime ver-tical mixing (96-98) and thus are unfavorable for the for-mation of NPSTMW; while the situation is completely re-versed in the early 1990s (93-95).展开更多
文摘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%), se-quently. 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.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos 40276009 and 40333030).
文摘Mesoscale eddy effects on the wintertime verti-cal mixing in the formation region of the North Pacific Sub-tropical Mode Water (NPSTMW) are studied using hydro-graphic data from Argo profiling floats deployed in the Ku-roshio recirculation region in February and March of 2001. Anticyclonic (warm) eddy enhances the wintertime vertical mixing and results in the deep mixed layer and the deep thermocline. Consequently, a large volumetric water mass with low potential vorticity corresponding to the prototype of NPSTMW tends to be formed. By contrast, cyclonic (cold) eddy is unfavorable for the vertical mixing process and halts the deepening of the mixed layer and thus the formation of mode water. Further analysis shows that cyclonic eddies prevail in the late 1990s in the formation region of NPSTMW, which lead to significant suppression of the wintertime ver-tical mixing (96-98) and thus are unfavorable for the for-mation of NPSTMW; while the situation is completely re-versed in the early 1990s (93-95).
