近百年来全球、大洲和区域尺度降雨时空变化诊断(1900-2010)

Spatial and Temporal Variations in Global,Continental and Regional Scale Rainfall over the Past 100 Years(1900-2010)

采用1900-2010年0.5°×0.5°的降雨数据诊断全球、七大洲和IPCC26个陆地分区的降雨气候态分布特征、变化趋势和波动特征。结果表明:(1)在气候态降雨量上,全球年均降雨量主要分布在30°S^30°N,特别是20°S^20°N,仅非洲和南美洲年均雨量高于全球。年均降雨量SEA(东南亚分区)最高,SAH(撒哈拉分区)最少,不同季节伴有不同变化。(2)在变化趋势上,1900-2010年全球降雨量变化趋势呈现出不同的时空分布特征,且以减少趋势为主。在大洲上,亚洲、非洲和南极洲呈减少趋势,且6-8月减少最多,9-11月减少最少。在IPCC 26个陆地分区上,12个分区呈增加趋势,14个分区呈减少趋势。(3)在波动特征上,1900-2010年全球陆地降雨量波动特征较高的地区主要分布在撒哈拉、以青藏高原为核心的周边地区、南美洲西部山脉地区和南极洲内陆地区,不同季度的降雨量均大于年均降雨量波动特征,且大洋洲和南极洲四个季度波动特征大于其它五个大洲。在IPCC 26个陆地分区上,仅8个分区年均降雨量波动特征波动特征超过了0.10。

Rainfall at different scales of the world has changed in the context of climate change. Based on the rainfall dataset of 0. 5° × 0. 5° over 1900-2010 years,the distribution characteristics,variation trend and fluctuation characteristics of rainfall climate in the seven continents and IPCC 26 land partition in the world were diagnosed. Results show that： Firstly,in the climate of rainfall,the global average annual rainfall is mainly distributed at 30°S ~30°N,especially 20°S ~ 20°N,the average annual rainfall in Africa and South America is higher than the global. The average annual rainfall with maximum is SEA（Southeast Asia）,the minimum is SAH（Sahara）,and varies with different seasons. Secondly,in the variation trend,the trend of global rainfall shows different temporal and spatial distribution characteristics from 1900 to 2010,and the main trend is decreasing trend. On continents scale,Asia,Africa,and Antarctica showed a decreasing trend,with the most reductions from June to August months and the fewest reductions from September to November. On the 26 land partition based on IPCC,the 12 partitions showed an increasing trend,and the 14 partitions showed a decreasing trend. Thirdly,in the fluctuation characteristics,global land rainfall fluctuation characteristics in higher areas are mainly distributed in the Sahara,on the Tibetan Plateau as the core of the surrounding area,the mountains of western South America and Antarctica inland areas from 1900 to2010,different seasonal rainfall were higher than the average annual rainfall fluctuation characteristics,and characteristics of the four quarter of Oceania and Antarctica is more volatile than the other five continents. On the 26 land partitions based on IPCC,only 8 partitions have the characteristics of annual rainfall fluctuation over 0. 10.