Warming over the Eurasia continent and Variations of the Atmospheric Circulation in Recent

Abstract

The singular value decomposition (SVD) analysis is applied to examine relationship between lower-tropospheric temperature over the Eurasia continent and atmospheric circulation in the Northern Hemisphere for 30 years from 1967-1996. The cluster analysis using 5-days mean data is applied to detect the change of regime transition. The first mode of the temperature (SVD1) has amplitude in East Asia, the Scandinavian Peninsula and Polar region. The first mode of the atmospheric circulation is closely related to the teleconnection pattern known as PEA with decadal scale. The score time series of this mode shows climatic jump in winters of 1976/77, 1988/89. Similar interannual and interdecadal variabilities are appeared in the regime of 5-days mean as well. On the other hand, the second mode of temperature (SVD2) shows recent warming in the Eurasia continent. This atmospheric circulation mode is similar to the NA and NAO of the teleconnection pattern and seems to be connected strongly with the variability of the Iceland low than the Siberian high. Consequently, fluctuation of the recent lower-tropospheric temperature over the Eurasia continent is probably related with Polar low and atmospheric circulation in the North Atlantic Ocean region. It is found that NAO might play a role for the warming over the Eurasian continent by the isolating to two components; decadal-scale jump and increasing trend with different processes.