Assimilating operational SST and sea ice analysis

Authors: Qiyan Ji Xueming Zhu Hui Wang Guimei Liu Shan Gao Xuanliang Ji Qing Xu

Publish Date: 2015/06/06

Volume: 34, Issue: 7, Pages: 54-64

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Abstract

The prediction of sea surface temperature SST is an essential task for an operational ocean circulation model A sea surface heat flux an initial temperature field and boundary conditions directly affect the accuracy of a SST simulation Here two quick and convenient data assimilation methods are employed to improve the SST simulation in the domain of the Bohai Sea the Yellow Sea and the East China Sea BYECS One is based on a surface net heat flux correction named as Qcorrection QC which nudges the flux correction to the model equation the other is ensemble optimal interpolation EnOI which optimizes the model initial field Based on such two methods the SST data obtained from the operational SST and sea ice analysis OSTIA system are assimilated into an operational circulation model for the coastal seas of China The results of the simulated SST based on four experiments in 2011 have been analyzed By comparing with the OSTIA SST the domain averaged root mean square error RMSE of the four experiments is 174 116 130 and 091°C respectively the improvements of assimilation experiments Exps 2 3 and 4 are about 333 253 and 477 respectively Although both two methods are effective in assimilating the SST the EnOI shows more advantages than the QC and the best result is achieved when the two methods are combined Comparing with the observational data from coastal buoy stations show that assimilating the highresolution satellite SST products can effectively improve the SST prediction skill in coastal regionsFoundation item The Ocean Public Welfare Industry Research Special of China under contract No 201105009 the Fundamental Research Funds for Central Universities of China under contract No 2013B20714 the National Natural Science Foundation of China under contract Nos 41222038 and 41206023 the National Basic Research Program of China 973 Program under contract No 2011CB403606

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