CTD data on standard levels collected during July and December in 1998 and the cubic spline interpolating method were used to study the characteristics of the transition layer temperature and salinity. The thermocline...CTD data on standard levels collected during July and December in 1998 and the cubic spline interpolating method were used to study the characteristics of the transition layer temperature and salinity. The thermocline undergoes remarkable seasonal variation in the South China Sea (SCS), and especially in the region of the north shelf where the thermocline disappears in December. The thermocline is stronger and thicker in July than in December. There is no obvious seasonal variation in the halocline. Due to the upper Ekman transport caused by monsoon over the SCS, the thermocline slopes upward in July and downward in December from east to west in the northern SCS. The characteristics of the thermocline and halocline are influenced by local eddies in the SCS. The Zhujiang diluted flow influences significantly the SCS shelf’s halocline.展开更多
The SODA data generated from a numerical model with data assimilation axe used to study the decadal thermal anomalies in the thermocline of the South Pacific. Three notable events of decadal thermocline variations are...The SODA data generated from a numerical model with data assimilation axe used to study the decadal thermal anomalies in the thermocline of the South Pacific. Three notable events of decadal thermocline variations are found. First, two major warm subduction events originated from outcrop regions centered at 30°S, 150°W in the South Pacific Ocean occurred between 1960s and 1980s propagating toward the western Tropics and at 30°S, 90°W in the late 1970s propagating directly toward the eastern Tropics. Second, a special westward warm event originating from the eastern boundary around 15°S occurred in the early 1980s. Thirdly, a distinct zonal location transition of the positive temperature anomalies near 10°S took place in the late 1970s. The results suggest that the warm events in the subtropical South Pacific region are important to the decadal variability of the western tropical Pacific before the late 1970s and to the eastern tropical Pacific after the late 1970s.展开更多
文摘CTD data on standard levels collected during July and December in 1998 and the cubic spline interpolating method were used to study the characteristics of the transition layer temperature and salinity. The thermocline undergoes remarkable seasonal variation in the South China Sea (SCS), and especially in the region of the north shelf where the thermocline disappears in December. The thermocline is stronger and thicker in July than in December. There is no obvious seasonal variation in the halocline. Due to the upper Ekman transport caused by monsoon over the SCS, the thermocline slopes upward in July and downward in December from east to west in the northern SCS. The characteristics of the thermocline and halocline are influenced by local eddies in the SCS. The Zhujiang diluted flow influences significantly the SCS shelf’s halocline.
基金Supported by The National Natural Science Foundation of China (Nos. 40406004, 40490263 and 40306002) and by the University Doctorate Foundation (No.20030423004).
文摘The SODA data generated from a numerical model with data assimilation axe used to study the decadal thermal anomalies in the thermocline of the South Pacific. Three notable events of decadal thermocline variations are found. First, two major warm subduction events originated from outcrop regions centered at 30°S, 150°W in the South Pacific Ocean occurred between 1960s and 1980s propagating toward the western Tropics and at 30°S, 90°W in the late 1970s propagating directly toward the eastern Tropics. Second, a special westward warm event originating from the eastern boundary around 15°S occurred in the early 1980s. Thirdly, a distinct zonal location transition of the positive temperature anomalies near 10°S took place in the late 1970s. The results suggest that the warm events in the subtropical South Pacific region are important to the decadal variability of the western tropical Pacific before the late 1970s and to the eastern tropical Pacific after the late 1970s.
