Precipitation and atmospheric circulation patterns at mid‐latitudes of Asia

Abstract

Analyses of the coupling between large-scale atmospheric patterns and modifications of regional precipitation regimes at seasonal and annual time scales in different terrain of mid-latitudes in Asia, including western Siberia, Tien Shan and Pamir mountains, and plains of middle Asia and Japanese Islands, were examined based on data from 57 and 88 hydro-climatic stations with 100 and 60 year records, respectively. For the past 100 years, a positive trend in precipitation was revealed in western Siberia, northern regions of Tien Shan and Japanese Islands. North Atlantic Oscillation (NAO) and West Pacific Oscillation (WPO) indices have inverse associations, with average amount of precipitation in western Siberia and in mountains and plains of middle Asia, and positive correlation in central and western regions of Japanese Islands. The Pacific North American (PNA) index is positively correlated with annual precipitation over most of the Japanese Islands. Northern Asian (NA) positive anomalies lead to decrease in winter precipitation in the western and eastern regions of Japanese Islands. We did not find significant impact of PNA or NA on precipitation in middle Asia. We suggest that during the last century, impacts of the western jet stream increased in the northern regions of Tien Shan and Japanese Islands, and weakened in the eastern Japanese Islands. There is a suggestion that conditions are more favourable for precipitation development over continental regions of Asia when the Siberian High is positioned further to the east than further to the west. During dominant development of a zonal atmospheric pattern, the annual and seasonal precipitation decreased over most regions in continental Asia and central Japan.

A seasonally lagged signal of the North Atlantic Oscillation (NAO) in the North Pacific

“…The warm surface water extends westward during the spring, leading to a lagged response in the atmosphere associated with the weakened spring Aleutian Low. Aizen et al (2001) have suggested that the NAO is one of main atmospheric circulation factors determining the climate in continental Asia, which is different from those affecting the Japanese Islands. From our studies, the evidence has showed that the winter NAO influences not only the winter Northern Hemisphere climate but also the subsequent spring climate including the North Pacific region through both North Pacific SST and Eurasian snow mechanisms.…”

“…In particular, the positive phase of the NAO is associated with an increase in precipitation over northern Europe and a decrease in precipitation over central and southern Europe as well as North Africa (Lamb and Peppler, 1987;Hurrell, 1995). Recently, NAO-related precipitation signals in the Middle East and Asia have also been identified (Cullen and deMenocal, 2000;Aizen et al, 2001;Visbeck et al, 2001). For example, Aizen et al (2001) investigated the atmospheric circulation patterns associated with seasonal and annual precipitation anomalies in central Eurasia and Japan and showed that the NAO has an influence on the winter precipitation in these regions.…”

“…Recently, NAO-related precipitation signals in the Middle East and Asia have also been identified (Cullen and deMenocal, 2000;Aizen et al, 2001;Visbeck et al, 2001). For example, Aizen et al (2001) investigated the atmospheric circulation patterns associated with seasonal and annual precipitation anomalies in central Eurasia and Japan and showed that the NAO has an influence on the winter precipitation in these regions. In particular, they identified a dipolar response with precipitation over continental Asia and western Siberia being negatively correlated with the NAO, while that over western Japan is positively correlated.…”

Reconstruction of the mass balance of Muztag Ata No. 15 glacier, eastern Pamir, and its climatic drivers

“…In addition, it can be deduced that a change in the amount of snowfall for these regions was mainly the result of changes in the amount of precipitation based on the above statements. With increases in precipitation in the main precipitation seasons (Hewitt, 2005;Yao and others, 2012;Kapnick and others, 2014;Zhang and others, 2017), such as in winter in the Karakoram, and in the ablation season in the Muztag Ata region, this leads to increases in snowfall and further decreases in melt energy in the ablation season due to increasing albedo under warming and and others, 2016), the mean air temperature was higher during 2001-2012than 1970(Zhang and others, 2017. This means that a greater mass loss occurred during the period of 2001-2012 than during 1970-2000 for these regions, which was in contrast with the observed regional glacier changes.…”

Climatic imprint of the mid-latitude Westerlies in the Central Tian Shan of Kyrgyzstan and teleconnections to North Atlantic climate variability during the last 6000 years

“…), about 50 km east of Son Kol, the average annual precipitation amounts to ~400 mm (Williams and Konovalov, 2008), it is clearly higher at the lake itself (500-600 mm; Academy of Science of the Kyrgyz SSR, 1987). Most of the precipitation in the area occurs as convective rainfall during summer, driven by moist westerly air masses (Aizen et al, 2001), whereas only about 20% fall between November and March (Academy of Science of the Kyrgyz SSR, 1987) because of the blocking of the Westerlies by the Siberian Anticyclone in winter.…”