Abstract:

The spatial and temporal characteristics of Arctic sea ice are studied using the monthly data for sea-ice concentration from the Hadley Center, NCEP/NCAR reanalysis data and best-track data from the Regional Specialized Meteorological Center (Tokyo) Typhoon Center of the Japan Meteorological Agency from 1977 to 2011. The relationship between the winter-spring sea-ice variation and tropical cyclone in the Northwest Pacific is discussed. It is found that the variation of winter-spring sea ice in the Arctic has obvious decadal changes and oscillated with a period of  3—4 years from 1965 to 2004. There were significant changes in sea ice in the late 1960s and early 1970s. The connection between sea-ice anomalies and tropical cyclone is more marked in September than in other months. There is a positive correlation between winter-spring sea ice and tropical-cyclone strength. There is a strong negative correlation between winter-spring sea ice and the Western Pacific Subtropical High. When there is more (less) winter-spring sea ice than average, the summer 500hPa geopotential height is lower (higher) than usual in eastern North American, Iceland, the North Pacific and medium-low latitudes. A persistent relevance between winter-spring sea ice and the northern-hemisphere atmospheric circulation is recognized in the following typhoon season.

Key words: rctic sea ice, tropical cyclone, Western Pacific Subtropical High, persistent relevance