华南秋季蒸发量的时空演变特征

SPATIAL AND TEMPORAL VARIATIONS OF EVAPORATION OVER SOUTHERN CHINA IN AUTUMN

利用华南区域66个气象站点1960～2004年的观测数据分析了华南秋季蒸发皿蒸发量和实际蒸发量的时空变化。分析结果表明:华南中部和西北部是华南秋季蒸发皿蒸发量的两个主要气候变异中心区,华南中部秋季蒸发皿蒸发量具有以年代际变化为主的特征,并且在45年内总体上呈下降趋势。在影响蒸发皿蒸发量的因子中,太阳辐射与蒸发皿蒸发量的相关性最好,呈显著的正相关。对实际蒸发量而言,华南中部和西部偏西地区则是两个主要的变异中心,两区域的秋季实际蒸发量具有以年际变化为主的特征,降水对华南秋季实际蒸发量的影响最为显著,华南秋季实际蒸发量一般都在蒸发皿蒸发量的40%左右,并且比值总体上呈现微弱的由南向北递增趋势。

The spatial and temporal variations of the instrument-based evaporation and actual evaporation in autumn during a 45-year period from 1960 to 2004 are studied using the observation data at 66 stations over southern China. The results reveal that two main anomalous centers of the instrument-based evaporation in autumn are located in the central and northwestern parts of the southern China respectively. The instrument-based evaporation over the central part of the southern China in autumn experiences not only a decreasing trend, but also a main interdecadal variation. The solar radiation is correlated mostly with the instrument-based evaporation among all affecting factors. For the actual evaporation, two main anomalous centers are located at the central and western parts of the southern China respectively. The actual evaporation over the two regions illustrates the interannual variation. Among the affecting factors, the precipitation is the most remarkable. The actual evaporation is usually 40 percent of the instrument-based evaporation, and the overall rate has a slightly increasing trend from the southern part to the northern part of the southern China in autumn.