Influence of Siberian High on temperature variability over northern areas of South Asia

Abstract

Siberian High pressure plays a significant role in wintertime climate variability over South Asia. It brings coldest air masses in the region. The available literature has linked Siberian High with climate of East Asia, central Asia, and Eurasia. This paper examines the linkage between Siberian High pressure and inter-annual variations in temperature over the region of South Asia during winters. The methods employed in this study are that of centers of action approach, maximum covariance, and canonical correlation analyses. The wintertime temperature is not only significantly influenced by the intensity of Siberian High pressure, but it is also significantly correlated with zonal movement of Indian Ocean High. The intensity of Siberian High pressure explains more variance of the temperature during winters over the South Asian region than that of large-scale circulation phenomena, namely, Arctic Oscillation, North Atlantic Oscillation, and El-Nino-Southern Oscillation. A linear model of wintertime temperature has also been constructed using the Siberian High pressure index and the Indian Ocean High longitudinal index, which explains 28% variability of wintertime temperature for the Northern part of South Asia. We have also presented the justification that this statistical evidence is supported by the circulations and changes in the atmosphere. The modes having maximum possible covariance between the regional wintertime temperature and sea-level pressure of Siberian High have been isolated using the method of maximum covariance analysis and the modes having maximum possible correlations between the two fields have been isolated using canonical correlation analysis.