Studies on the Water Vapor Transportation, Precipitation and Atmospheric Disturbances over the Norwegian Sea Regions Affecting the Climate in the Northern Hemisphere

点击翻译按钮获取中文摘要

It is well known that the Norwegian Sea region is very important to understand the energy and water vapor transformation in the northern hemisphere because the Norwegian Sea does not freeze in the midwinter seasons. Therefore, the baroclinic zone is formed among a warm air-mass which is originated in the mid-latitude and a cold air-mass which is originated in a high latitude region. Under such conditions, the polar lows are generated around the zone frequently. To investigate the structures, activity and precipitation phenomena of the atmospheric disturbances, the X-band vertically pointing Doppler radar of the Graduate School of Science, Hokkaido University was set up at the Bear Island (Bjornoya) Weather Observatory in Norway (74°30′N, 19°01′E). Continuous observations had been conducted through three years from September 2001 to August 2004. The radar observations in this region is the first time till the present.To estimate the spatial distribution of precipitation intensity from t … More he radar data obtained, the relationship between radar reflectivity (Z) and precipitation intensity (R), and precipitation intensity (R) and falling velocity of precipitation particles (V_p) were investigated. As a result, the actual circumstances of the precipitation intensity and water contents over the Norwegian Sea region were clarified.Furthermore, the radar data which was obtained at Ny-Alesund station (78°55′N, 20°25′E) in the Svalbard, Norway, of National Institute of Polar Research of Japan, was analyzed. As a result, the radar echoes showed distinct seasonal variations with respect to height, and clarified into four patterns.The observations of snow crystals and aerosol particles were conducted through four winter seasons at the Arctic Research Center, Sodankyla, Finland, and a number of interesting results were obtained.The densification phenomena and compressive viscosity of the depth of snow cover at the Arctic regions were investigated and compared with the temperate regions. Less