VARIATIONS OF THE ANTARCTIC SEA ICE AND POLAR VORTEX INDEX IN SOUTHERN HEMISPHERE AND THEIR RELATIONSHIPS

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  • Chinese Academy of Meteorological Sciences, PML., Beijing 100081

Received date: 1994-05-01

  Revised date: 1994-08-01

  Online published: 1996-01-15

Abstract

In this paper Cluster Analysis was used for grouping the similar regions of the variability of the Antarctic sea ice, and five regions were obtained based on the Antarctic sea ice extent data of 17 year period (1973--1989). The indices of the polar vortex area and the intensity in southern hemisphere were calculated using of 500hPa monthly mean data in the same period.The analysis of the features of temporal and spatial variations of the Antarctic sea ice and polar vortex as well as their relationships is presented by using statistic analysis. The results show that the discrepancy of climatic characteristics and interannual variability of the sea ice and polar vortex are obvious. They oscillate with cycles of 2 2. 5 years and 5 7 years over most of the regions. The linear trend of the sea ice anomaly reveals that 4 of the 5 regions exhibit a trend of reducing sea ice.The trends of the polar vortex coverage anomaly for all regions are negative similar to that of sea ice, while the corresponding trends of polar vortex intensity are predominantly positive over 3 regions. The above statistical facts is consistent with the effect of global warming.Cross-correlations among concurrent anomalies of the variables are most signifcant from the Southeast Pacific area (e. g., Antarctic Peninsula, region 5) to the South Atlantic area (region 1 ). Lag correlations between them are also closer to the sea ice leading the polar vortex cover and lagging the polar vortex intensity in region 1. The correlations are larger with the sea ice lagging both of the cover and intensity of the polar vortexm in region 5.

Cite this article

Bian Lingen, Lu Longhua, Jia Pengqun . VARIATIONS OF THE ANTARCTIC SEA ICE AND POLAR VORTEX INDEX IN SOUTHERN HEMISPHERE AND THEIR RELATIONSHIPS[J]. Acta Geographica Sinica, 1996 , 51(1) : 33 -43 . DOI: 10.11821/xb199601004

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