摘要
针对资料同化时模式与观测资料不协调导致的同化失效问题,利用国家气候中心NCCo简化海气耦合模式,基于一种提取观测资料中与模式相协调信息分量(也称模式可协调信息)的资料重构方法,探讨了观测资料和模式的协调性对资料同化效果的影响。结果发现:利用简单海气耦合模式同化海表温度距平资料时,由于模式与资料不匹配使同化后的初始场中产生与模式动力特征不协调的小尺度扰动,这些小扰动在预报阶段会迅速增长,污染预报结果,使得预报失败。研究还发现,无论在耦合或不耦合同化形式下,对海温资料中的模式可协调分量进行同化时,预报效果明显好于对原观测资料的同化。其缘于对观测海温中模式可协调信息分量同化生成的初始场中,消除了与模式动力特征不协调的小尺度扰动,突出了原始资料中与模式协调的ENSO尺度信息分量,改善了初始场与模式的协调性,从而提高了模式的预报技巧。
To resolve the problem caused by incompatibility between the dynamic model and observational data in the assimilation, the effect of model compatible part of observational information on the assimilation is explored by utili- zing the NCCo model and a method of separating the model compatible part of information from the observational da- ta. The researches show that the predictions are rather poor when the observational SSTA data are assimilated di- rectly by the simple ocean atmospheric coupled model, as the NCCo model, because the assimilated initial fields con- tain too much small scale disturbances which are incompatible with the dynamic features of model and grow up rapid- ly in the integrating process. However, the effect of assimilation could be greatly improved by just assimilating the model compatible part of observational data whether the assimilation circumstance is uncoupled or not, because the initial fields primarily contain ENSO scale information, which matches the dynamical spatial and temporal scales of the NCCo model.
出处
《大气科学》
CSCD
北大核心
2009年第4期796-810,共15页
Chinese Journal of Atmospheric Sciences
基金
国家重点基础研究发展规划项目2006CB403600
国家自然科学基金资助项目40675039
国家科技支撑计划项目2006BAC02B04
关键词
资料同化
模式可协调分量
data assimilation, model compatible information in observational data
