作　　者： ; ; ; ;

机构地区： 中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室

出　　处： 《气候与环境研究》 2008年第6期697-707,共11页

摘　　要： 利用一个新的四维变分海洋资料同化系统LICOM-3DVM对TOPEX/Poseidon高度计资料进行了同化。该同化系统是在LASG/IAP气候海洋模式LICOM1.0的基础上建立起来的,所用的同化方法为三维变分映射资料同化方法3DVM。高度计观测资料是采取间接的方式进行同化,即先建立起二维海面高度距平场与三维温度场的统计关系,并由此通过观测的海面高度距平信息反演出"观测"的三维温度场,然后利用LICOM-3DVM四维变分同化系统将此反演的温度场同化到海洋模式中。作者设计了两组试验并对结果进行了比较分析,积分时间从1993年1月至2001年12月共9年时间。结果表明,由于上混合层相关系数较小,因此同化后海温没有改进;而在温跃层以及更深层次,同化后的海温均有很大程度的改善。从对赤道太平洋地区海温的气候态、季节变化和年际变化以及Nio3区的Nio指数的模拟情况来看,由于同化时将海面高度异常和海温异常之间的相关参数取为常数,没有考虑其季节和年际变化,因此,同化后对于赤道太平洋的年际变化没有改善。对于黑潮地区,由于模式的分辨率较低,同化之前没有很好地模拟出温度锋面,温度和盐度梯度都偏小,流速也偏弱;而同化后使得温度锋面和盐度梯度与WOA01更加吻合,流速增强。 A global oceanic four-dimensional variational data assimilation system called LICOM-3DVM is applied to assimilate TOPEX/Poseidon altimeter data. This system is established using the three-dimensional variational data assimilation of mapped observation （3DVM） and the LASC-/IAP Climate Ocean Model, version 1.0 （LICOM1.0）. A statistical method is used to convert sea surface height anomalies into synthetic temperature profiles. And then the synthetic temperature profiles are assimilated. Two experiments starting from January 1993 and ending at December 2001 are designed to examine the assimilation skill of synthetic temperature profile, one is the control run （CTRL） and the other is the assimilation （ASSM）. The results from ASSM show great improvements in the thermocline and deeper levels while little improvements in the mixed layer since the small correlation coefficient there. From the analysis to the climatology, seasonal and interannual variability of the temperature and Nino 3 index in the equatorial Pacific, there is no improvement after assimilation since the correlation factor between variations of the sea surface height and the subsurface temperature is treated as a constant without considering its high seasonal and interannual variability. For the Kuroshio area, the comparison shows that the simulation by the model is not able to reproduce a correct Kuroshio Stream temperature front prohably due to the coarse resolution. The gra- dient of the temperature and salinity are small, and the zonal velocity is weaker. However, the results from ASSM show the coincidence of the temperature front and the salinity gradient with WOA01.

关 键 词： 三维变分映射资料同化 高度计资料 四维变分

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