关键词: 湍流通量;感热通量;动量通量;曳力系数;热源;热汇;垂直输送;相似理论通量—廓线关系;瑞穗站

Abstract:

This paper describes the results of observation on the fluxes of momentum and sensible heat over Mizuho Station (70°41' 53 " S, 44°19 ' 54 " E), East Antarctica. The data were collected by using the meteorological tower 32m high at this station in 1979-1981 period. These fluxes were evaluated by semiemperical flux-profile relation of Monin-Obukhov similarity theory from these observed data, and the calculated result was compared with that over the West Pacific Tropical Ocean area and Beijing area. 1.For the stable atmosphere the drag coefficient CDS is (1.05±0.01)×10-3, and for the unstable atmosphere it (CDUN) is (1.26±0.15) x 10-3.The drag coefficient CDUN for unstable atmosphere is larger than that (CDS) for stable atmosphere. The magnetude of the drag coefficient CD is obviously correlated with atmosphere stability. Bisides, the drag coefficient CDUN for unstable atmosphere is obviously correlated with the gradient Richardson number Ri. 2.This Antarctic area is a cold source on the Earth where the sensible heat flux has obviously annual variation and different diurnal variation- for different seasons. In winter (August) the sensible heat flux absorbed from the atmosphere is about 114W. the largest among all seasons. It is about 94W in autumn (May), 24W in spring (October), and about 12W in summer (January), the least among all seasons, i.e. only about 1/10 of that in winter. The diurnal variation of the sensible heat flux for different seasons are different over this station. In autumn and winter the sensible heat flux has no obvious diurnal variation. This is similar to that over the West Pacific Tropical Ocean area. However, it is essentially different. The Antarctic area is a cold source where the sensible heat is transferred from atmosphere to ice (or snow) surface, but the West Pacific Tropical Ocean area is a heat source where the sensible heat is transferred from sea to atmosphere. In spring and summer the sensible heat flux has obvious diurnal variation. The daytime sensible heat flux is positive, and transferred from ice (or snow) surface to atmosphere. The nighttime sensible heat flux is negative and transferred from atmosphere to ice (or snow) surface. This is similar to that over Beijing area. But on the average for a day, it is also essentially different. The Antarctic area is a cold source where the net transfer of sensible heat is negative. But Beijing area is a heat source where the net transfer of sensible heat is positive.