摘要
土壤湿度是影响气候的重要因子之一,但观测资料的欠缺制约着该领域研究工作的开展。本文汇总了目前国际上运用较为广泛的四套土壤湿度资料：ERA40和NCEP/NCAR再分析资料、全球土壤湿度计划资料（GSWP2）、以及NCAR最近完成的利用观测资料强迫＂＂通用陆面模式＂＂CLM所产生的土壤湿度资料。在此基础上,利用中国区域观测的19年（1981~1999年）的土壤湿度和13年（1992~2004年）的土壤相对湿度资料,对四套资料在中国区域的可靠性进行了分析和比较,主要结论如下：四套资料基本揭示出土壤湿度的空间分布,GSWP2揭示了四套资料最多的共性,即东北、华南湿,华北、西北干,土壤湿度基本由西北向东北和东南呈梯度增加的特征;GSWP2较好地描述了土壤湿度的季节循环;ERA40土壤湿度的年际变化与观测相关最好;观测资料和四套资料都表明前期降水会增加土壤湿度,但土壤湿度异常对后期降水的影响则不显著;气温与土壤湿度的关系较复杂,不同的区域有不同的特征。
Soil moisture is one of the most important factors affecting the climate. However, deficiency of data coverage has limited the progress of soil moisture studies in terms of its role in climate. In this paper, four sets of widely-used soil moisture data are collected, i.e. the European Centre for Medium Range Weather Forecasting （ECM- WF） 40-year reanalysis （ERA40）, the National Centers for Environmental Prediction/National Center for Atmos- pheric Research （NCEP/NCAR） reanalysis data, Global Soil Wetness Project product, and the output of the Community Land Model forced by observational atmospheric conditions. Qualities of these four sets of soil moisture data over China's Mainland are evaluated by using observational evidences. The results show that the spatial patterns of the four soil moisture data sets generally agree well with the observation. The GSWP2 data are the best one among four datasets in producing the observational pattern, i. e., the soil moisture gradually increases from northwestern to northeastern and southeastern China, with northeastern and southern China being wet, northern and northwestern China being dry. The seasonal cycle of GSWP2 soil moisture is also better than any of the others. The ERA40 data have the highest correlation with the observation in producing the interannual variability of the soil moisture. All data show significant positive correlation between the precipitation and later time soil moisture, while no significant correlation can be found between precipitation and preceding soil moisture. The relationship between the soil moisture and air temperature is complex and the results are region-dependent.
出处
《大气科学》
CSCD
北大核心
2008年第3期581-597,共17页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金资助项目40523001、40221503
国家重点基础研究发展规划项目2005CB321703
中国科学院创新团队国际合作伙伴计划“气候系统模式研发及应用研究”
关键词
土壤湿度
空间分布
季节循环
年际变化
资料比较
soil moisture, spatial distribution, seasonal cycle, interannual variation, multi-data intercomparison
