BCC_CSM模式夏季长江中下游水汽输送评估  

Summer Prediction of Moisture Transport in the Middle and Lower Reaches of the Yangtze River in BCC_CSM Mode

作　　者：汪栩加[1] 郑志海[2] 顾伯辉 赵玉衡 

机构地区：[1]兰州大学大气科学学院,兰州730000 [2]中国气象局国家气候中心,北京100081

出　　处：《高原气象》2016年第5期1270-1279,共10页Plateau Meteorology

基　　金：国家重点基础研究发展计划(2013CB430204);国家自然科学基金项目(41475096);公益性行业(气象)科研专项(GYHY201306021;GYHY201306024)

摘　　要：基于国家气候中心第二代季节预测模式的回报数据集与NCEP再分析数据,首先分析了夏季长江中下游地区大气水汽含量以及水汽输送特征,在此基础上分析了该地区水汽输送与长江中下游降水及夏季风之间的配置关系。进一步对模式的水汽输送预测能力进行了评估,并对造成模式误差的可能原因进行了分析。研究表明,夏季长江中下游降水与东亚夏季风联系密切,而东亚夏季风主要通过影响长江中下游的水汽输送来影响该地区降水,因此水汽输送是联系水汽源地与降水的一个重要的枢纽;另一方面,模式中夏季长江中下游大气水汽输送较观测而言存在一个气旋性偏差,不利于水汽输送到该地区,这导致了长江中下游大气可降水量偏少,从而成为该地区降水的预测总体偏少一个重要原因,这种负偏差中心分布在20°N-40°N之间,而低纬度则是一个正偏差分布。进一步研究发现,模式对于长江中下游水汽输送的预测偏差主要是由夏季风的预测偏差导致的,且模式对于弱季风年的预测能力要强于强季风年。Based on hindcast datasets datasets, using correlation analysis, of the Beijing Climate Centre climate system model and NCEP reanalysis composite analysis and others, firstly, the summer atmospheric moisture content and the characteristics of moisture transport in the middle and lower reaches of the Yangtze River are ana- lyzed, and the relationship between rainfall and the summer monsoon are discussed. Secondly, the pattern of moisture transport simulation capabilities are evaluated, and possible reasons for the model error are analyzed. Results shows that： （ 1 ） summer precipitation in the Yangtze River has a close relationship with the East Asian summer monsoon, and the East Asian summer monsoon affects mainly through the moisture transport in Yangtze River to influence precipitation, moisture transport is therefore an important hub contact between precipitation and water origin; （2） there is a cyclonic bias of atmospheric water vapor transportation in low latitude of Yang- tze River, which led to atmospheric moisture content of the Yangtze River decrease, this is an important reason for the precipitation simulation of below normal level in this region, negative biases simulation centers distribut- ed between 20°N - 40°N, while low latitudes is a positive deviation distribution. Further studies shows that the simulation of the deviation of the Yangtze River moisture transport mainly caused by an analog deviation the sum- mer monsoon, and the simulation of the weak monsoon is better than the simulation of strong monsoon.

关 键 词：BCC_CSM模式 水汽输送 回报 评估 

分 类 号：P435[天文地球—大气科学及气象学]