阿拉伯海区域气溶胶时空动态变化及海域叶绿素a浓度特征

Spatio-temporal dynamic characteristics of aerosol and chlorophyll a concentration in the Arabian Sea

基于2003—2017年的MODIS/Aqua气溶胶和海洋叶绿素a浓度遥感数据资料,分析了阿拉伯海域气溶胶光学厚度(AOD)的时空动态变化及海域叶绿素a浓度(Chl-a)特征,并探讨了该海域气溶胶和海洋叶绿素a浓度的关系。结果表明:阿拉伯海区域AOD和Chl-a的空间分布都呈现出显著的季节性变化,且总体呈现出由近岸向外海逐渐降低的特征,其大小和分布受到陆源沙尘影响显著;海域AOD夏季高于春季,冬季高于秋季,15年间海域AOD整体呈现增加趋势,其中东部海域增加较明显,北部海域无显著变化;海域Chl-a秋冬季明显高于春夏季,变异性较高;由春冬季AOD与Chl-a的相关系数分析发现,二者相关性在阿拉伯海西北部区域显著性相关,且呈现出由北向南、由近海岸向外海区逐渐减弱的趋势。

The spatial distribution and temporal variation of aerosol optical depth(AOD)and the characteristics of chlorophyll a concentration(Chl-a)in the Arabian Sea,were inter-annually and seasonally analyzed by utilizing the MODIS/Aqua AOD and chlorophyll products during 2003 to 2017,and the relationship between the aerosol and chlorophyll a concentration was discussed for the sea area.The results showed that the spatial distributions of AOD and Chl-a changed more significantly with the seasons in the Arabian Sea,and generally showed a gradual decrease from offshore to the open seas.The value and spatial distribution of the AOD and Chl-a were obviously affected by the dust in the land-sourced desert.The AOD was higher in summer than spring,and in winter was higher than that in autumn.During the past 15 years there appeared an increasing trend of the AOD,especially in its east coastal area,but no significant change occurred in the north coast.The specific performance of Chl-a was higher in autumn and winter,lower in spring and summer,and its variability was high.From the correlation coefficient analysis between AOD and Chl-a in spring and winter,the correlation between AOD and Chl-a was significantly correlated in the northwestern Arabian Sea,and it showed a trend of decreasing from north to south and from the coast to the outer sea.