Recent Changes in the East Asian Monsoon

Studies on the recent changes of the summer and winter monsoons,with priority on decadal-interdecadal scales,are reviewed briefly in this paper.The major changes in the East Asian summer monsoon（EASM） include a weakening of the EASM and a shift in precipitation patterns at the end of 1970s;an increase in South China precipitation after 1992-1993;a decrease in precipitation in the middle-and-lower reaches of the Yangtze River and an increase in precipitation in the Huaihe River valley after 1999;and instability in the relationship between the EASM and El Niño-Southern Oscillation（ENSO）.The changes in the East Asian winter monsoon（EAWM） include a weakening of the EAWM and its interannual variability after the mid-1980s,an increase in winter snowfall in Northeast China after the mid-1980s,and a weakening of the EAWM-ENSO relationship after the mid-1970s.In addition,the impact of the autumn Arctic sea ice decline on the winter snow cover in the Northern Hemisphere is discussed.These changes in EASM and EAWM indicate that the extreme climate and phenology have been significantly altered.