Long-term changes of teleconnection linked to Mongolian summer precipitation variability

Abstract

Mongolia, located in the northern edge of mid-latitude of Asian continent, has experi-enced weather and climate disasters such as drought and flood. Because of the lack of reservoir and dam, the source of fresh water is largely from precipitation during summer season. Also, on account of its heavy focus on the primary industries, summer rainfall is critical in national productivity. Given that almost half of annual precipitation is concentrated in July and August (JA), in this paper we defined the two months as summer, analysed long-term changes of Mongolia summer precipitation and large-scale circulation teleconnection pattern related to this. Summer precipitation, which showed a slight increase in 1901-1950, showed a significant decline since the 1960s, and the severity and the frequency with which extreme events occur have been in-creased. This change in Mongolia summer precipitation is related to that in the large-scale circu-lation pattern, and especially zonally elongated teleconnection pattern further extended to the Pacific Ocean. Interestingly, NAO and Northern Indian precipitation have become strongly correlated with Mongolia summer precipitation anomaly in recent years. Considering the two variables together, we could explain about 40 percent of the total variance of the recent Mongolia sum-mer precipitation.