SPATIAL AND TEMPORAL INTER-ANNUAL VARIATIONS OF SEA SURFACE TEMPERATURE IN THE CONTINENTAL SHELF OF THE EAST CHINA SEA
东海陆架表层水温年际变化时空特征分析

Using the AVHRR data(1982—2011) in the East China Sea(ECS) and the in-situ monitoring data(1960—2001) of Shengshan and Xiamen stations which are located at the northern and southern sides of the ECS coast,spatial and temporal inter-annual variations of sea surface temperature(SST) in the continental shelf of the ECS are analyzed.(1) Based on reliability analysis and verification of the satellite data,spatial distribution of correlation coefficients between SST time series of the coast stations and that of each lattice point in ECS are calculated,and it suggests that SST variation trends of this two stations have certain representativeness in broad shelf of the ECS,i.e.Shengshan represents the inner shelf and Xiamen represents the Taiwan Strait areas.(2) The in-situ monitoring data and the calibrated satellite data are merged into 52-year’s monthly SST from 1960 to 2011 and the inter-annual variations of SST in the inner shelf and the Taiwan Strait have been analyzed.The warming trends were found especially in winter and the inner shelf(Shengshan) became warming quickly than the Taiwan Strait(Xiamen).In the inner shelf,there were two winter SST shifts from cold to warm phase in 1977/1978 and in 1994/1995 respectively,and the temperature was increased by 2.34℃ within 52 years.The shifts in spring,summer and autumn all existed in 1994,and the SST increased by 1.19℃,1.43℃ and 1.16℃ in those seasons.In the Taiwan Strait,weaker shifts from cold to warm existed for all seasons,i.e.with 0.91℃ rising in 1989/1990 in winter,with 0.38℃ rising in 1987/1998 in summer,with 0.80℃ rising in 1996/1997 in spring and with 0.58℃ rising in 1995/1996 in autumn.(3) More quantitatively,a 30-year time series of AVHRR SST data is examined using EOF analysis to understand the spatial and temporal variations in continental shelf of ECS.The largest inter-annual variation was found in the inner shelf adjacent to the Changjiang estuary.This was mainly influenced by the mixing between seawater and freshwater.Coastal current,Taiwan Warm current and the Changjiang diluted water changed with monsoon and precipitation and brought different water masses.This could induced the less heat flux to the lower water column and made the SST increasing quickly than other areas like middle shelf of ECS or the Yellow Sea.