Analysis on Characteristics of Precipitation Change from 1957 to 2015 in Weishan County

The climatic changes of annual precipitation, annual, seasonal, monthly and abrupt change of precipitation in Weishan County from 1957 to 2015 were calculated by using linear regression analysis, cumulative anomaly method and Morlet wavelet analysis. The results show that the annual, intertemporal, seasonal and monthly precipitation of different seasons shows a decreasing trend in different degrees. From 1960s to 1980s, the precipitation was decreasing, and the precipitation was decreasing from 1990s to 2010s. The annual precipitation decreased with the trend of linear trend of -13.0 mm/10a. The annual precipitation changed in 1969, 1974, 2003 and 2009. The cycle of annual precipitation was mainly in 8 and 32.

南极气候变化的季节特征

利用１９６２～１９９３年南极１６站地面至３０ｈＰａ１０个标准层上月平均温度、南极臭氧总量以及２８００ＭＨｚ太阳通量资料，采用最大熵功率谱方法，研究了各季中月南极诸高度气候的线性趋势变化、熵谱特征及其可能原因。结果显示：南极平流层气温（臭氧总量）在各月均呈变冷（减少）趋势，１０月１００ｈＰａ气温（臭氧总量）１０年的变率最大达－１．８℃（－１４．８％）。南极对流层气温（２８００ＭＨｚ太阳通量）在各月均呈显著增暖（增强）趋势，１月５００ｈＰａ气温（太阳通量）１０年的变率高达０．４℃（２２．１个单位）。各月太阳通量均呈显著的３年及９～１０年甚低频—年代际周期变化。而对流层８５０～５００ｈＰａ气温变化熵谱仅在７月具有相应的特征，南极对流层顶气温在各季中月均无显著的趋势变化及周期性变化。提出南极春季臭氧的显著减少及夏季太阳通量的增强是平流层显著变冷及对流层变暖的重要原因；南极夏季对流层显著增暖导致南极大陆边缘部分冰雪消融，可能是近年来全球海平面升高的重要原因之一。