大气初始异常在跨季度短期气候预测中作用的研究

A Study of the Impact of Initial Atmospheric Anomalies on Extraseasonal Short-term Climate Prediction

针对大气初始异常在跨季度短期气候预测中的可能作用 ,利用中国科学院大气物理研究所 9层大气环流格点模式 (简称IAP 9L AGCM )对全球夏季气候进行了 30年 ( 1 970～ 1 999年 )集合回报试验 ,系统地考察了基于大气初始异常条件下模式对跨季度短期气候异常的可预测性。结果表明 ,在热带、副热带及高纬都存在气候异常的可预测性区域 ,说明大气初始场异常本身对跨季度短期气候预测有很重要的影响。相对于全球来说 ,大气初始异常对跨季度短期气候预测的影响在东亚地区更为显著 ,其作用不可忽略。通过对典型年份的个例分析发现 ,在某些气候异常剧烈的特殊年份 。

Focusing on the potential impact of initial atmospheric anomalies on extraseasonal short-term climate prediction, the grid point Atmospheric General Circulation Model with 9 vertical levels, developed at the Institute of Atmospheric Physics, the Chinese Academy of Sciences, is used to perform the numerical experiment of ensemble hindcasting for thirty years (1970～1999). The predictability of extraseasonal short-term climatic variations due to the initial atmospheric anomalies is systematically evaluated in this study. It is shown that climate anomalies are regionally predicable in some regions over the tropics, subtropics, and even high latitudes, which indicates that the initial atmospheric anomaly is an important factor for the extraseasonal short-term prediction of climate anomalies. Furthermore, its effect is more distinct in East Asia compared with the global, and, therefore, it cannot be neglected if one aims for forecasting short-term climatic anomalies in this region. In addition, particular attention is paid to a few years with larger climatic anomalies. It follows that the initial atmospheric anomalies occurred in spring play a very important role in the following summer climate activities over China's Mainland.