摘要
海底压强对解析海平面收支和海洋深部环流动力机制具有重要意义。基于2002—2024年GRACE卫星反演的海底压强观测数据,本文系统分析了阿拉伯海海底压强的时空变化特征及其动力机制。结果表明,阿拉伯海海底压强变化的年振幅呈显著空间差异,中心海区的振幅较大,外围海域相对较小;海底压强的月际变化在全海域表现出空间一致性,季节演变特征表现为冬季(1月—3月)负异常与夏季(7月—9月)正异常的双峰结构。结合ERA5再分析数据发现,阿拉伯海海底压强变化存在南、北海区动力过程分异特征:南部海域海底压强受风应力旋度主导,风应力旋度超前海底压强约1个月(相位差30°),二者呈负相关关系;北部海域由风生埃克曼过程调控,埃克曼抽吸超前海底压强约1个月,二者呈正相关关系。上述南、北海区的动力分异机制,可归因于经向平均大气压的边界约束效应。进一步研究发现,印度洋偶极子对阿拉伯海海底压强的影响呈现季节不对称性:夏季平均海底压强与超前6个月的偶极子指数呈显著相关,而冬季的相关性则不显著。
The study of ocean bottom pressure(OBP)is great significance for understanding the mechanisms of sea level budget changes and deep ocean circulation.Based on 23 years of OBP data observed by the Gravity Recovery and Climate Experiment(GRACE)satellites,this study systematically reveals the spatiotemporal characteristics and mechanism of OBP variations in the Arabian Sea.There is a strong OBP oscillation center in the central area of the Arabian Sea.The OBP changes throughout the region are unified in space and time.It has significant seasonal variation features,showing a double-peak structure of negative anomalies in winter(January to March)and positive anomalies in summer(July to September).Combining the reanalysis data of ERA5,it is found that there is a dynamic divergence mechanism of OBP oscillation between the northern and southern areas of the Arabian Sea.The southern area is dominated by wind stress curl,with a negative correlation response leading OBP by 30°(about 1 month).The northern area is regulated by the wind-driven Ekman process,with Ekman pumping/suction leading by 1 month to trigger a positive correlation.This divergence mechanism is attributed to the boundary constraint effect of the meridional mean atmospheric pressure standard deviation.The impact of the Indian Ocean Dipole(IOD)on OBP shows seasonal asymmetry:in summer,OBP is significantly correlated with the dipole mode index(DMI)leading by 6 months,while in winter,the correlation between the mean OBP and the DMI in each mounth is not significance.
作者
章坤
张涛
邬宾杰
张登
郑华
丁睿彬
ZHANG Kun;ZHANG Tao;WU Binjie;ZHANG Deng;ZHENG Hua;DING Ruibin(Second Institute of Oceanography,MNR,Hangzhou 310012,China;Technology Innovation Center for Marine Intelligent Observation,MNR,Hangzhou 310012,China)
出处
《海洋学研究》
北大核心
2026年第1期83-92,共10页
Journal of Marine Sciences
基金
中央级公益性科研院所基本科研业务费专项资金项目(JG2316,JG2509)。
