1948～2001年全球陆地及大尺度区域6～8月旱涝气候变化

用 1 948～ 2 0 0 1全球陆地月降水资料 (PREC/L) ,研究了全球、北半球、南半球及欧亚、非洲、澳洲、北美、南美和南极大陆等 6个大尺度区域 6～ 8月的旱涝气候变化。结果表明 ,全球及北、南半球 6～ 8月的旱涝有明显的年代际变化。 2 0世纪 40年代末～ 70年代为全球洪涝多发期 ,80～ 90年代为全球干旱多发期。北半球的特征与全球较为一致 ;南、北半球 6～ 8月的旱涝没有明显的联系 ,但发生暖 (冷 )事件时 ,两个半球可能同时出现干旱(洪涝 ) ;全球、半球的旱涝与ENSO有明显的联系。另外 ,非洲大陆和欧亚大陆旱涝年的分布有十分明显的年代际特征 ,6个大区域 6～ 8月的旱涝之间存在一定的联系。

Climatic Change of Flood/Drought of Global Land and Large-Scale Areas in June-August during 1948-2001

The flood/drought characteristics of global, the Northern and Southern Hemispher es, Eurasia, Africa, Australia, North America, South America and Antarctica in J une-August (JJA) are investigated, based on global land monthly precipitation da taset PREC/L during the period of 1948-2000 The results indicate that the floo d/drought characteristics of global, northern and southern hemisphere experience d decadal change: during 1950s-1970s global flood in JJA occurred frequently, an d from 1980s-1990s global drought in JJA occurred frequently The flood/drought characteristics of the Northern Hemisphere are agreed with ones of the global There is no obvious correlation between the northern and southern hemispheric f lood/drought in JJA However when the warm (cold) event occurs, the drought (fl ood) may happen in JJA in the Southern and Northern Hemispheres The flood/drou ght in JJA over global, the Northern and Southern Hemispheres are highly correla ted with the ENSO events In addition, the flood/drought characteristics of Eur asia and Africa experienced marked decadal change, and there are some relationsh ips among flood /drought of the six large-scale areas