The construction of high precision geostrophic currents based on new gravity models of GOCE and satellite altimetry data  

作　　者：Wenyan Sui Junru Guo Jun Song Zhiliang Liu Meng Wang Xibin Li Yanzhao Fu Yongquan Li Yu Cai Linhui Wang Lingli Li Xiaofang Guo Wenting Zuo 

机构地区：[1]School of Marine Science and Environment Engineering,Dalian Ocean University,Dalian 116023,China [2]Operational Oceanographic Institution,Dalian Ocean University,Dalian 116023,China [3]Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou),Guangzhou 511458,China [4]Institute of Marine Science,Hebei Normal University of Science and Technology,Qinhuangdao 066600,China [5]Tianjin Marine Environmental Monitoring Central Station,Ministry of Natural Resources,Tianjin 300457,China

出　　处：《Acta Oceanologica Sinica》2021年第3期142-152,共11页海洋学报（英文版）

基　　金：The Open Fund of Key Laboratory of Marine Environmental Information Technology;the Open Foundation of Technology Innovation Center for Marine Information,Ministry of Natural Resources;the Liao Ning Revitalization Talents Program under contract No.XLYC1807161;the Dalian High-level Talents Innovation Support Plan under contract No.2017RQ063;the National Natural Science Foundation of China under contract Nos 41206013 and 41430963;the Scientific Research Project of Liaoning Province Department of Education under contract No.QL201905;the Projects of Institute of Marine Industry Technology of Liaoning Universities;the grant from Key R&D Program of Liaoning Province under contract No.2019JH2/10200015;the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)under contract No.GML2019ZD0402;the Shandong Provincial Key Research and Development Program(SPKR&DP)under contract No.2019JZZY020713.

摘　　要：The new gravity field models of gravity field and steady-state ocean circulation explorer(GOCE),TIM_R6 and DIR_R6,were released by the European Space Agency(ESA)in June 2019.The sixth generation of gravity models have the highest possible signal and lowest error levels compared with other GOCE-only gravity models,and the accuracy is significantly improved.This is an opportunity to build high precision geostrophic currents.The mean dynamic topography and geostrophic currents have been calculated by the 5th(TIM_R5 and DIR_R5),6th(TIM_R6 and DIR_R6)release of GOCE gravity field models and ITSG-Grace2018 of GRACE gravity field model in this study.By comparison with the drifter results,the optimal filtering lengths of them have been obtained(for DIR_R5,DIR_R6,TIM_R5 and TIM_R6 models are 1°and for ITSG-Grace2018 model is 1.1°).The filtered results show that the geostrophic currents obtained by the GOCE gravity field models can better reflect detailed characteristics of ocean currents.The total geostrophic speed based on the TIM_R6 model is similar to the result of the DIR_R6 model with standard deviation(STD)of 0.320 m/s and 0.321 m/s,respectively.The STD of the total velocities are 0.333 m/s and 0.325 m/s for DIR_R5 and TIM_R5.When compared with ITSG-Grace2018 results,the STD(0.344 m/s)of total geostrophic speeds is larger than GOCE results,and the accuracy of geostrophic currents obtained by ITSG-Grace2018 is lower.And the absolute errors are mainly distributed in the areas with faster speeds,such as the Antarctic circumpolar circulation,equatorial region,Kuroshio and Gulf Stream areas.After the remove-restore technique was applied to TIM_R6 MDT,the STD of total geostrophic speeds dropped to 0.162 m/s.

关 键 词：GOCE gravity field model mean dynamic topography geostrophic current 

分 类 号：P715.6[天文地球—海洋科学]