Atmospheric Water Vapor Measurements at Mizuho Camp, East Antarctica in 1976-1977

Abstract

The measurement of air humidity at the height of 1.5 meters above the snow surface was made at Mizuho Camp, East Antarctica, several times a day during the summer in 1976-1977, with the Karl Fisher method and the Assmann ventilated psychrometer method. The values of air humidity obtained by these two methods agreed within approximately 5% error. Water vapor pressure was estimated from the air humidity at temperatures between -6.5 and -22.8℃. The water vapor pressure obtained showed daily variation similar to air temperature. During the measurement no supersaturation of water vapor with respect to ice was detected and no ice fog was observed. The relative air humidity was between 30 and 80%. It was lower under a condition of predominant katabatic winds than under an influence of cyclones. The daily mean amount of sublimation estimated from the water vapor pressure obtained was between 1.3 and 1.9 millimeters per day and it was nearly two or three times larger than the amount of sublimation obtained by a direct measurement, snow stake measurement.