A study of surface humidity changes in china during the recent 50 years
A study of surface humidity changes in china during the recent 50 years
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DOI：
10.1007/s13351-012-0501-9
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发表时间：
2012-11
影响因子：
--
通讯作者：
Yafang Song;Yanju Liu;Yihui Ding
中科院分区：
文献类型：
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作者：
Yafang Song;Yanju Liu;Yihui Ding
本文利用中国国家气象信息中心编制的观测资料，详细分析了近50年来全球变暖背景下中国地面湿度变化的特征。结果表明：（1）随着温度的升高，地表饱和比湿（qs）基本呈指数增长，符合Clausius-Clapeyron方程;冬季全国平均增湿率明显小于年平均增湿率和夏季增湿率。我国不同地区的劳动强度存在一定的区域差异。（2）除东部华南和江淮地区外，我国大部分地区尤其是西部地区年比湿和冬季比湿均呈一致的增加趋势。夏季，除东北、西北部分地区和青藏高原部分地区外，中国大部分地区降水量呈明显的下降和干燥趋势，与全球平均情况不一致;（3）中国大部分地区地面相对湿度呈下降趋势。相对湿度降低的主要原因之一是q的增长率小于qs。然而，中国中东部地区的相对湿度呈上升趋势，这主要是由于这些地区在夏季观察到的降温和上升，导致降水增多。从2003年前后开始，我国大部分地区qshas显著增加，qleq急剧下降，相对湿度大幅度降低。这可能与近10年来我国干旱面积持续增长密切相关。
This paper analyzes in detail the characteristics of surface humidity changes in China under the background of global warming in the recent 50 years by using the observation data compiled by the National Meteorological Information Center of China. The results reveal that (1) with the increase of temperature, surface saturation specific humidity (qs) shows basically an exponential growth, according to the Clausius-Clapeyron equation. The nationwide average moistening rate in winter is obviously less than the annual average rate and the summer rate. There are some regional differences inqstrends in different regions of China. For example,qsin central and eastern parts of China exhibits a reducing trend in summer, consistent with the weakening trend of temperature in these areas; (2) except parts of South China and Jianghuai Region in eastern China, unanimously increasing trends of annual and winter specific humidity (q) are found in most of China, especially in western China. In summer, except parts of Northeast China, Northwest China, and some areas over the Qinghai-Tibetan Plateau, the decreasing and drying trends are significant in most of China, which is not consistent with the global mean situation; (3) the surface relative humidity (RH) in most of China shows a reducing trend. One of the major reasons for the reduction of RH is that the increasing rates ofqare smaller than those ofqs. Nonetheless, upward trends of RH in central and eastern China mainly due to the cooling temperature and risingqin these regions are observed in summer, leading to more precipitation. From about 2003 or so,qshas remarkably increased whileqhas sharply decreased in most parts of China; therefore, RH has reduced to a great extent. This may be closely related to the persistent growth of drought areas in China in the recent 10 years.