利用ARGO资料改进ENSO和我国夏季降水气候预测

Utilizing ARGO Data to Improve the Prediction of ENSO and Short-term Climate Prediction of Summer Rainfall in China

  • 摘要: 全球海洋ARGO资料的获取为气候预测的研究提供了前所未有的海洋资料。该文首先利用ARGO资料改进次表层参数化方案后的Zebiak-Cane海洋模式, 与统计大气模式耦合, 建立了热带动力海洋-统计大气耦合模式。通过比较应用和未应用ARGO资料改进的海洋模式, 进行了耦合模式的长期回报试验。结果表明:ARGO资料的应用极大地改善了耦合模式对热带太平洋海面温度异常的预测能力, 提前3个月和6个月的回报结果都有很大的改进, 基本上回报出了Niño3.4区海面温度异常的演变特征, 对厄尔尼诺和拉尼娜都能够给出较准确的回报, 回报结果与观测之间的相关性在整个热带太平洋区域明显提高。该文还利用国家气候中心 (NCC) 全球海气耦合模式, 对我国夏季降水进行了个例和多年季度回报模拟试验, 探讨了包含和不包含ARGO观测资料的同化资料作为初始场对我国夏季降水预测的影响, 表明采用带有ARGO观测资料的海洋同化初始场, 回报的我国夏季降水分布形式与观测更一致, 回报结果与观测之间的正相关区域变大, 对我国夏季降水的回报水平比采用没有ARGO观测资料的海洋同化初始场时有明显提高。

     

    Abstract: The acquirement of the global ARGO data provides unprecedented ocean data for researches on the climate prediction, a tropical dynamic ocean-statistical atmospheric coupled model is set up. In the coupled model, the atmospheric part is a statistical atmospheric model constructed according to the correlation relationship between observed windstress and sea surface temperature in the tropical Pacific. The ocean part is Zebiak-Cane oceanic model in which the subsurface temperature parameterization scheme is improved based on the ARGO data. The long-term hindcasts are done using the coupled model. In order to understand the performance of the ARGO data in the improvement of the hindcasts, the results of the coupled model are compared using the unimproved and improved ocean models respectively. It is found that the application of the ARGO data in the oceanic model greatly raises the capability of the coupled model in hindcasting the sea surface temperature (SST) in the tropical Pacific. The hindcast of 6 months in advance gives the abnormal variations of the SST in the Niño3.4 region in good agreement with the observation. The El Niño and La Niña events in the hindcasting period are successfully hindcasted. The correlation of SSTs between the hindcasts and the observations is increased substantially in the whole tropical Pacific Ocean.The improvement of the short-term climate prediction of summer rainfall in China is also investigated by using the global atmosphere-ocean coupled model of the China National Climate Center (NCC) using the ARGO data in the Global Ocean Data Assimilation System of NCC (NCC-GODAS). The results of seasonal hindcasts for the summer precipitation in China for the case of the summer of 2002 and also for the summers from 1998 to 2003 are showed respectively. It is found that when the ARGO data is included in the NCC-GODAS, the distribution of the hindcasted summer precipitation in China is closer to the observation. The area of the positive correlation between the hindcasted and the observed summer precipitations is enlarged. It demonstrates that hindcasts for the summer precipitation in China with ARGO data in the NCC-GODAS is much better than those without ARGO data.

     

/

返回文章
返回