同化卫星高度计观测对CAS-ESM-C上层海洋温度模拟的改进  

Satellite Altimetry Data Assimilation in CAS-ESM-C:Benefits for Improving the Simulations of Upper Ocean Temperature

作　　者：杨海鹏 陈权亮[1] 林壬萍[2] 杜梦蛟 郑飞[2] YANG Haipeng;CHEN Quanliang;LIN Renping;DU Mengjiao;ZHENG Fei(College of Atmospheric Sciences,Chengdu University of Information Technology,Key Laboratory of Sichuan Province of Plateau Atmosphere and Environment,Chengdu 610225,China;Center for International Climate and Environmental Sciences,the Institute of Atmospheric Physics,Chinese Academy of Sciences,Beijing 100029,China)

机构地区：[1]成都信息工程大学大气科学学院高原大气与环境四川重点实验室,四川成都610225 [2]中国科学院大气物理研究所国际气候与环境科学中心,北京100029

出　　处：《成都信息工程大学学报》2019年第6期615-624,共10页Journal of Chengdu University of Information Technology

基　　金：国家自然科学基金资助项目(41875108)

摘　　要：为有效改进中国科学院地球系统模式气候分量系统(CAS-ESM-C)对年际海洋变化信号的模拟,利用集合最优插值同化方法(ensemble optimal interpolation,EnOI)将海表高度(sea surface height, SSH)数据同化入CAS-ESM-C。通过对比3种不同来源的平均动力地形(mean dynamic topography, MDT)数据对SSH同化性能的影响,筛选出针对CAS-ESM-C海洋资料同化最优的MDT。在此基础上,实施了1994-2000年的SSH观测同化试验,检验其对CAS-ESM-C海洋状态模拟的改进效果。结果表明,正是由于海洋上层(温跃层以内)的温度变化与SSH有着较强的动力相关性,同化SSH观测可以显著地改进CAS-ESM-C对海洋上层温度变化、海气耦合循环和物理过程的模拟。0~400 m全球平均的均方根误差能控制在1.0℃以内;温跃层深度附近的改进效果最为显著;热带太平洋上层海洋热含量的年际变化以及赤道太平洋地区海温年际异常演变明显优于仅同化海表温度(sea surface temperature, SST)的改进效果。由此可以得到,同化SSH改进了CAS-ESM-C对海洋上层年际变率的模拟,为下一步利用CAS-ESM-C开展短期气候预测奠定了基础。With the motivation to improve the simulation of oceanic interannual variations effectively, the sea surface height(SSH) satellite altimetry data was assimilated into CAS-ESM-C by using Ensemble Optimal Interpolation(EnOI).In this study, the best MDT was selected firstly based on its influences on simulation performance. Using the selected MDT,a SSH assimilation experiment was conducted from 1994 to 2000, comparing with a SST assimilation experiment. Comparing with SST assimilation, the SSH assimilation during 0-400 m subsurface temperature showed better performance, the global mean RMSE was lower than 1.0 ℃.The most improvement region was located at the depth around thermocline.The reason was that SSH showed better correlations with the subsurface temperature than SST. Meanwhile,the simulated interannual variations of upper oceanic heat content and Tropical Pacific SST anomalies were largely improved in SSH assimilation, which means that the simulated air-sea coupling and physical process were improved in SSH assimilation. This study showed that the oceanic interannual variability could be largely improved by assimilating SSH rather than SST. This study implied that the SSH assimilation should be considered in short-term climate prediction.

关 键 词：卫星高度计 地球系统模式 数据同化 温跃层深度 海表温度 同化试验 中国科学院 太平洋地区 

分 类 号：P456.7[天文地球—大气科学及气象学]