A spatial analysis of pan evaporation trends in China, 1955-2000
A spatial analysis of pan evaporation trends in China, 1955-2000
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DOI：
10.1029/2004jd004511
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发表时间：
2004-08-07
影响因子：
4.4
通讯作者：
Gong, WG
中科院分区：
文献类型：
--
作者：
Liu, BH;Xu, M;Gong, WG
蒸发皿蒸发量是潜在蒸发量的一个指标，在过去几十年中，世界许多地区的蒸发皿蒸发量都有所下降。这一趋势与全球变暖将伴随着陆地蒸发量增加的预期相反，即所谓的蒸发皿悖论。本文利用1955 ~ 2000年中国85个气象站的资料，分析了蒸发皿蒸发量的空间格局变化。结果表明，1955 ~ 2000年中国蒸发皿蒸发量呈下降趋势。除东北地区外，中国所有八个气候区的减少都有统计学意义。我们还发现，太阳辐照度的减少很可能是中国蒸发皿蒸发量减少的驱动力。然而，与世界其他地区不同的是，在中国，太阳辐照度的减少并不总是伴随着云量和降水量的增加。因此，我们推测气溶胶可能在中国太阳辐照度下降中起着关键作用。将中国划分为8个气候区，发现蒸发皿蒸发量的减少率西北最大，西南最小。虽然太阳辐照度的变化是蒸发皿蒸发量减少的主要原因，但在比较八个气候区时，水分条件影响蒸发皿蒸发量对太阳辐照度变化的敏感性。因此，蒸发皿蒸发量的空间变化趋势与太阳辐照度的空间变化趋势在这些区域之间是不同的。
Pan evaporation, an indicator of potential evaporation, has decreased during the last several decades in many parts of the world. This trend is contrary to the expectation that global warming will be accompanied by an increase in terrestrial evaporation, known as the pan evaporation paradox. In this paper we present an analysis of changes in the spatial patterns of pan evaporation in China based on data from 85 weather stations from 1955 to 2000. We found that pan evaporation decreased in China from 1955 to 2000. The decrease was statistically significant in all of China's eight climatic regions except northeast China. We also found that the decrease in solar irradiance was most likely the driving force for the reduced pan evaporation in China. However, unlike in other areas of the world, in China the decrease in solar irradiance was not always accompanied by an increase in cloud cover and precipitation. Therefore we speculate that aerosols may play a critical role in the decrease of solar irradiance in China. By subdividing China into eight climatic regions, we found that the rate of decrease in pan evaporation was highest in the northwest and lowest in the southwest. Although changes in solar irradiance are the main cause of decreasing pan evaporation, water conditions influence the sensitivity of pan evaporation to the change in solar irradiance in comparing the eight climatic regions. Thus the spatial trends of pan evaporation differ from those of solar irradiance among these regions.