南极瑞穗站的辐射特征

CHARACTERISTICS OF RADIATION OVER MIZUHO STATION IN ANTARCTICA

本文利用1979～1980年南极瑞穗站太阳分光辐射,长波辐射及微气象观测资料,分析了辐射分量,地表和大气有效比辐射,大气分光有效透射比的年季变化;雪面反射率和分光散射辐射与太阳高度角的关系;分光散射辐射和总辐射之比与大气质量的关系。

Measurements of radiation components and micrometeorological were carried out in the lower boundary layer at Mizuho Station (70°42′S, 44°20′E, 2230m above sea level), Antarctica in a period 1979 to 1980. In this paper,the annual variations of radiation compoments, the effective emissivity of snow surface and atmosphere,the effective transmittance of atmosphere, snow surface albedo have been calculated and analyzed. Relationships of the snow surface albedo and the spectral diffuse fluxes with solar elevation angle under clear sky have been analyzed also. The preliminary results demonstate that: (1) Radiation components have obvious annual variation, 0—420Wm^(-2) and 0—318.9Wm^(-2) for global and reflected radiation. The annual of mean value of net radiation is—14Wm^(-2). The annual of mean value of net radiation is—14.6Wm^(-2),the minimum value of monthly mean is—33.5Wm^(-2) in July and the maximum value is 14.0Wm^(-2) in December. The annual vatiations of terrestrial radiation and atmospheric counter radiation were—165— —252Wm^(-2) and 126—185 Wm^(-2)respectively. Say for radiation balance,the Antarctica area is a cold source(heat sink). (2)The annual of average value of effective emissivity of surface and atmosphere were 0.99 and 0. 77, respectively. (3)The season diurnal variation of effective spectral transmittance of atmosphere is obvious. (4)The annual average value of snow surface albedo were 0.79, 0.95 and 0.64 for 305—2800nm,305—695nm and 695—2800nm. (5)In the 305—695nm region,the ratio of spectral diffuse with global is quite small and increases very slowly according to the air mass.