冬季の総観規模擾乱に伴う南極昭和基地の昇温現象

Abstract

It has been reported before that Antarctic temperature suddenly rises especially at surface when synoptic scale distubance arrives. Authors have examined the mechanism of this warming by the data observed at Syowa Station in mainly 1993 by the 34 th Japanese Antarctic Research Expedition (JARE 34). The study is mainly done for the periods of 11 prominent warming events and done on the two points.The first is the contribution of destruction of temperature inversion on the surface. By comparison of vertical profiles of temperature before and after the events, it has been shown that strong temperature inversion made by radiative cooling was destroyed. Its average contribution for surface temperature's rise has been shown 8.2 K for 21.8 K.The second is the contribution of horizontal advection of sensible heat in upper layers.Heating rate estimated from it has been larger than the observed value. The discrepancy is regarded mainly due to cooling by vertical upward motion. Vertical velocity has been estimated about 0.3-0.9 cm/s upward.