基于CESM气候模式的同化模拟实验

A data assimilation experiment based on CESM

利用nudging方法将GODAS次表层海温资料同化到"通用地球系统模式"(CESM)中,并分析了同化后的海温、降水、海表面气压等海洋、气象要素。结果表明,同化后的模拟结果与GODAS、NCEP、GPCP等资料的结果较为一致,较好的再现了中低纬海洋和大气的平均特征和随时间演变的规律,NINO3指数的相关系数达到0.90。但模拟结果仍存在一些问题,如大西洋西边界流偏强,赤道辐合带降水偏多等。

A simple GODAS sub-surface sea temperature nudging scheme is developed for Community Earth System Model （CESM） released by National Center for Atmospheric Research （NCAR）. The simulation results for the period 1982--2001 show well matched patterns of oceanic and atmospheric variables including SST, sea surface currents, precipitation, zonal wind and sea level pressure with GODAS, NCEP and GPCP datasets. The average characteristics and varying pattern over time of ocean and atmosphere at mid-low latitudes like ENSO phenomena are also well simulated with the correlation coefficient of NINO3 index is 0.90. However, there are some problems including a positive bias of precipitation in ITCZ and stronger west boundary currents.