Evolution of Arctic Ocean surface circulation from 1958 to 2017

Abstract

Arctic Ocean surface circulation plays an important role in the global ocean circulation system. In recent years, its position and velocity have been changing constantly, attracting increasing attention. The cause of this change, however, is still a matter of disagreement. In this paper, we use empirical orthogonal function analysis (EOF) to analyze the spatial and temporal distributions of sea level pressure (SLP), sea surface height (SSH) and sea surface temperature (SST) in the Arctic Ocean. We use the wavelet transform to obtain the periodic variation law governing Arctic Ocean surface circulation as well as to explore the relationship between the Arctic Oscillation (AO) and Arctic Ocean surface circulation. Our results show that the SSH of the Arctic Ocean exhibit a periodic variation with AO, in particular the sudden change seen from 1987 to 1992 coinciding with the trend of the AO index for the same period. When the AO index is positive, the Beaufort Gyre (BG) weakens and the source of transpolar drift (TPD) moves eastward, to the East Siberian Sea; when the AO index is negative, the BG accelerates and expands and the source of TPD moves to the New Siberian Islands. As a result, the direction and amplitude of the circulation change.