南极长城站海雾特征分析

本文根据对海雾气象要素场、大气层结和天气形势的分析及其持续时间和季节、年际变化的统计分析,结合个例,讨论了南极长城站海雾的特征和形成机制。认为长城站海雾大多为平流冷却雾,高频率的偏北风和南大洋极锋附近显著的经向海温梯度是长城站多海雾的根本原因;夏半年海雾要多于冬半年,海雾的年际分布差异明显;海雾可出现于0-17m/s的各级风力中,3-11m/s偏北风最有利于海雾的维持;气温为-2-4℃、气-海温差为0-2℃时最易出现海雾;海雾的发生一般伴有稳定的大气层结;"东高西低"是长城站海雾的主要天气形势;海雾的持续时间取决于高压在南极半岛维持时间的长短,平均有10个小时。

ANALYSES OF SEA FOG AT GREAT WALL STATION,ANTARCTICA

The characteristics and the forming mechanics of the sea fog at Great Wall Station is discussed with analyses of the fields of weather elements,the atmospheric stratification and the synoptic situation,statistical analyses of the duration,seasonal and annual variation of the fogs there and case study.It is concluded that most sea fogs there are advection cooling fog,and the basic cause of the fog is the high-frequency northern winds and the great sea surface temperature gradient across the polar front at the Southern Oceans;There are more sea fogs in summer than those in winter with a significant interannual change;the sea fog can occur when the wind speed is between 0 to 17m/s,and the most favorable wind speed is between 3 to 11m/s;the sea fog tends to occur when the air temperature is between-2 to 4℃ and the difference between the air and the sea is 0 to 2℃;there is often a stationary stratification when the sea fog occurs;'High in the east,low in the west' is the main synoptic situation in which the sea fog at Great Wall Station occurs;The duration of the sea fog there depends on how long the high over the Antarctic Peninsula lasts,with an average about ten hours.