长江口邻近海域海表温度变化特征分析

Characteristics of the Sea Surface Temperature Variation in Adjacent Area of the Yangtze River Estuary

基于遥感数据,采用功率谱和相关性分析等方法,研究了长江口邻近海域海表温度(SST)的时空变化特征以及影响因素。结果表明:1982—2017年长江口邻近海域的SST整体表现为每10 a升温约0.48℃的趋势,且具有10.0,3.6,2.4和1.0 a的振荡周期。长期以来,冬、春、夏、秋四季的长江口邻近海域SST总体呈现升温趋势,其中春季的升温趋势最显著,而秋季变化趋势最不明显。研究海区的SST呈现明显西北—东南向温度递增的分布特征。此外,长江口径流量的变化对邻近海域的SST具有一定影响,从多年变化来看,径流量增大(减小),长江口邻近海域SST随之升高(降低),从月变化来看,3月、4月和9月的长江径流对SST有影响。气温对SST具有一定的强迫作用,大气温度的总体趋势是升高的,通过海气相互作用进行热传输,从而造成长江口邻近海域SST升温。

Based on remote sensing data,the characteristics and mechanisms of spatial and temporal variation of sea surface temperature(SST)in adjacent sea area of the Yangtze River estuary were studied with power spectrum and correlation analysis methods.The results show that the SST has an increasing trend of 0.48℃/(10 a)from 1982 to 2017 and significant oscillation periods of 10.0,3.6,2.4 and 1.0 years.Although the rising trend of SST exists in all seasons,the warming trend in spring is most significant while that in autumn is weakest.The SST increases from northwest to southeast in the area.In addition,the change in runoff of the Yangtze River has remarkable impacts on the SST variability,SST becomes warmer(cooler)when the runoff increases,and the impacts are most obvious in March,April and September.Atmospheric temperature above the Yangtze River estuary is significantly correlated with the SST.The general trend of atmospheric temperature has been rising,and this may cause the warming in SST due to positive heat flux from atmosphere to the sea through air-sea interaction.