基于Bio-Argo浮标数据研究孟加拉湾中部海域溶解氧分布

The distribution of dissolved oxygen in the central Bay of Bengal based on Bio-Argo observation

溶解氧的分布影响着海洋生物的生存,以孟加拉湾低氧区为研究对象,利用2013—2017年该海域Bio-Argo浮标数据和卫星遥感数据,分析孟加拉湾海域海洋上层(0—200m)溶解氧的垂直分布特征,探讨孟加拉湾海表溶解氧和氧跃层时空变化及其成因。结果表明,由于大量径流和降雨的输入,孟加拉湾海表形成显著的盐度成层,导致该海域溶解氧浓度在约40 m处开始显著降低,并在200 m以内降至20μmol·kg^(-1)以下。海表溶解氧浓度与海表温度呈负相关(r=–0.75)。氧跃层深度(DO50μmol·kg^(-1))与23℃等温线和海表面高度异常呈正相关,相关系数r分别为0.93和0.81。孟加拉湾中部低氧区海表温度是影响海表溶解氧变化的主要因素之一,氧跃层的变化则与海洋中尺度涡密切相关。

The distribution of dissolved oxygen(DO)affects the survival of marine organisms.In order to explore the temporal and spatial variation of sea surface DO and oxycline in the Oxygen Minimum Zone(OMZ)of Bay of Bengal(BoB),we investigated the vertical DO distribution from 0 to 200 m in the central BoB using Bio-Argo and remote sensing data from 2013 to 2017.The results showed that the salinity stratification caused by the input of a large amount of runoff and rainfall induced the significant change of the DO in the central BoB,and DO decreased significantly at~40 m,and dropped to less than 20μmol·kg^(-1) within 200 m.The sea surface DO was negatively correlated with the sea surface temperature(r=-0.75).The oxycline depth was significantly correlated with the 23℃isotherm and sea level anomaly(r=0.93 and 0.81).The surface DO concentration was mainly affected by the surface temperature,and the oxycline depth was mainly controlled by the mesoscale eddies in the OMZ of the BoB.