利用大气环流模式讨论舍入误差对东亚和西北太平洋夏季气候模拟的影响  

Influence of Round-off Error on Simulation of Summer Climate in the Northwestern Pacific and East Asia in an AGCM

作　　者：黄刚[1] 胡开明[2,3] 

机构地区：[1]中国科学院大气物理研究所东亚区域气候环境重点实验室,北京100029 [2]中国科学院大气物理研究所季风系统研究中心,北京100190 [3]中国科学院研究生院,北京100049

出　　处：《南京气象学院学报》2009年第2期155-163,共9页Journal of Nanjing Institute of Meteorology

基　　金：国家重点基础研究发展计划项目(2004CB4183002006CB400500);中国科学院知识创新工程重要方向项目(KZCX2-YW-220);国家自然科学基金资助项目(40775051U0733002);中国科学院知识创新工程领域前沿项目(IAP07314IAP07119)

摘　　要：采用单精度和双精度编译的大气环流模式对东亚以及西北太平洋气候进行集合模拟,分析舍入误差对大气环流模式在东亚和西北太平洋区域夏季气候模拟的影响,结果表明采用双精度编译的模式在850 hPa环流场比单精度模式模拟效果要好。为了进一步分析双精度模式模拟效果优于单精度模式的原因,集中研究了850 hPa纬向风场的模拟情况。结果表明,双精度模式对东亚以及西太平洋850 hPa纬向风场第1模态有着更好的模拟,而且第2模态的时间序列与再分析资料850hPa纬向风场的第2模态时间序列有着更好的相关。这些结果表明,由于舍入误差的影响使得该区域大气内部噪音更强烈,从而使得海温强迫导致的气候变率变弱,进而使得双精度编译的模式对东亚和西北太平洋区域气候的模拟要优于单精度模式。The influence of round-off error on summer climate simulation in the northwestern Pacific and East Asia has been investigated by using AGCM（atmospheric general circulation model） which is compiled by single precision and double precision.It is found that double precision computation has better skill than single precision one when simulating zonal wind at 850 hPa in the region.And the reason is also investigated,and the simulating results of 850 hPa zonal wind are mainly studied.The first empirical orthogonal function（EOF） mode of 850 hPa zonal wind simulated by double precision computation is better than that by single precision one,and the second mode time series of the double precision computations has a higher correlation coefficient with the second EOF mode time series of observations.Results show that the round-off error may result in higher atmospheric internal noise in the northwestern Pacific and East Asia,which can weaken the model simulation skill,therefore the double precision computation can better simulate climate than single precision one in this region.

关 键 词：舍入误差 西北太平洋 东亚气候 大气环流模式 

分 类 号：P435.2[天文地球—大气科学及气象学]