2011년 1월의 동아시아 한랭 아노말리 특성

Abstract

East Asia experienced extremely cold weather in January 2011, while the previousDecember and the following February had normal winter temperature. In this study NationalCenters for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data are used to investigate the characteristic features observed in the meteorologicalfields such as temperature, sea-level pressure, geopotential height, and wind duringthis winter period. In January the planetary-wave pattern is dominated by stationary-wave formin the mid-to-high latitude region, while transient waves are significant in the previous month. To understand the planetary-wave features quantitatively, harmonic analyses have been donefor the 500-hPa geopotential height field. In the climatological-mean geopotential heights thewave numbers 1, 2, and 3 are dominant during the whole winter. In January 2011 the waves ofnumber 1, 2, and 3 are dominant and stationary as in the climatological-mean field. In December2010 and February 2011, however, the waves of number 4, 5, and 6 play a major role andshow a transient pattern. In addition to the distinctive features in each month the planetarywavepatterns dependent on the latitude are also discussed.