基于再分析数据的南大洋区域Ekman流时空分布规律研究

Ekman transport in the Southern Ocean is an important part of the global atmosphere ocean coupled climate system. It is very important to study the Ekman dynamic process in this region. The Ekman current data provided by GEKCO2 product was evaluated and its validity verified. In addition, combined with sea surface wind products (CCMP and ERA5), EOF analysis and other methods were used to analyze the spatial and temporal variation of Ekman current in the Southern Ocean from 2010 to 2018. Results show that first, the speed of Ekman current ranged 9-11 cm/s with a strong inter-monthly oscillation (the strongest in July and the weakest in December). Secondly, the speed of Ekman current varied greatly with time north of 40°S in the Southern Ocean. Thirdly, The EOF analysis of the speed of Ekman current indicates that the first mode had a strong correlation with the wind field, in which the speed increased or decreased at the same time on the whole. The second mode had a strong correlation with the middle and high latitude atmospheric circulation in the southern hemisphere, in which the speed from north to south was reversed with 50°S as the boundary. Fourthly, the left deviation angle of Ekman current was distributed in the range of 60° to 75° with the maximum probability density at 67.5°. Through the analysis of complex correlation, it was found that the average deviation angle in the area of 30-35°S varied monthly. This study provides a reference for further understanding of the Ekman process in the Southern Ocean.