A PRELIMINARY STUDY ON DECADAL OSCILLATION AND ITS OSCILLATION SOURCE IN THE SEA-ICE-AIR SYSTEM IN THE NORTHERN HEMISPHERE

概要

論文の詳細を見る
By using maximum entropy and band-pass filter methods, the variation periods of sea ice area index in the Kara/Barents Seas, the intensity index of the Siberian High and winter monsoon over East Asia during winters from 1953 to 1990 were analyzed. And sea ice area variation in winter in the Kara/Barents Seas was compared with the area and intensity indices of the subtropical high in the following spring and summer. The results indicate that there is an obvious decadal variation in the sea-ice-air system in the Northern Hemisphere. The variations of intensity index of the winter Siberian High and the winter monsoon over East Asia are out of phase with that of sea ice area in winter in the Kara/Barents Seas. The more (less) sea ice there is, the weaker (stronger) the winter Siberian High and winter monsoon are. The variation trend of sea ice area is similar to that of the area and the intensity of the subtropical high in the coming spring and summer, with a lag period of 0-1 year. The decadal oscillation sources in the atmosphere are closely linked to specific sea regions. The center of the strongest oscillation source excited by winter sea ice in the Kara/Barents Seas is near 70°E, 60°N.