2:15 PM - 2:35 PM
[MIS15-14] Seasonal snow cover and surface energy balance characterized by the atmospheric condition in the Northern Japanese Alps region
★Invited Papers
Keywords:alpine region, seasonal snow cover, snowfall, surface energy balance
Northern Japanese Alps is one of the most major alpine regions in Japan. It has been lying on the south to north in central Japan and elevated up to approximately 3000 m a.s.l. and has a huge amount of snowfall. Snow cover is one of the important inland water resources in alpine regions and is closely related to other sub-systems (meteorology, ecology, and ground water) which composes the mountain environmental system. Thus, the seasonal snow accumulation and ablation process is essential factor to discuss the mountain environment.
In this presentation, as a regional characteristic of snow depth in the Japanese Alps region, we will focus on the analysis data of Norikura, Kamikochi, and Nishi-Hotaka among the meteorological observations in the southern part of the Northern Japanese Alps continuously conducted by Shinshu University. The works presented here are the research results conducted by the authors at Shinshu University, aiming at a comprehensive understanding of the natural environment in mountainous regions, and focusing on meteorology and snowfall as factors that have a significant impact on other natural elements.
This study focuses on the typical synoptic weather states that cause a large amount of snowfall in the Japanese Alps region: typical winter monsoon and south coastal cyclone. The spatial distribution of snowfall is suspected to be larger in there because of the difference in the advection paths of moist air masses between both weather conditions. This is also resulted from the different atmospheric conditions and precipitation amounts in the wind-ward and lee side areas of the steep mountain ranges.
The different warm and humid air mass are advected in both weather patterns. In the winter monsoon
We found the clear winter precipitation gradient in the Northern Japanese Alps region in north-south and west-east directions by the analysis of the observation data from Shinshu University and AMeDAS (Japanese Meteorological Agency). A clear north-south gradient in winter accumulated precipitation was observed in the AMeDAS data, with more precipitation in Japan Sea coastal area and less inland. And then, the specific snowfall patterns were found in those two weather states in west-east slopes of Mt Norikura due to the Shinshu University’s observation. Additionally, in Kamikochi region, which is located in a lee side area for the winter monsoon, atmospheric conditions and surface energy balance property was similar to those of a dry continental climate. Therefore, these results indicate that the precipitation is more intense in the windward area of the advection path of moist air, and this tendency is more pronounced in mountainous regions.
As described above, very interesting features of atmospheric condition and snowfall were revealed in Japanese Alps region created by the specific climate condition and topographic characteristic. In the situation that global warming has been reported, it could suspect that the large variation of precipitation phase will be conceived in the alpine region because it has a large spatial variation of air temperature. We would like to deepen our understanding of the seasonal snow cover in Japanese Alps region and discuss how the mountainous environment will change in the future.
In this presentation, as a regional characteristic of snow depth in the Japanese Alps region, we will focus on the analysis data of Norikura, Kamikochi, and Nishi-Hotaka among the meteorological observations in the southern part of the Northern Japanese Alps continuously conducted by Shinshu University. The works presented here are the research results conducted by the authors at Shinshu University, aiming at a comprehensive understanding of the natural environment in mountainous regions, and focusing on meteorology and snowfall as factors that have a significant impact on other natural elements.
This study focuses on the typical synoptic weather states that cause a large amount of snowfall in the Japanese Alps region: typical winter monsoon and south coastal cyclone. The spatial distribution of snowfall is suspected to be larger in there because of the difference in the advection paths of moist air masses between both weather conditions. This is also resulted from the different atmospheric conditions and precipitation amounts in the wind-ward and lee side areas of the steep mountain ranges.
The different warm and humid air mass are advected in both weather patterns. In the winter monsoon
We found the clear winter precipitation gradient in the Northern Japanese Alps region in north-south and west-east directions by the analysis of the observation data from Shinshu University and AMeDAS (Japanese Meteorological Agency). A clear north-south gradient in winter accumulated precipitation was observed in the AMeDAS data, with more precipitation in Japan Sea coastal area and less inland. And then, the specific snowfall patterns were found in those two weather states in west-east slopes of Mt Norikura due to the Shinshu University’s observation. Additionally, in Kamikochi region, which is located in a lee side area for the winter monsoon, atmospheric conditions and surface energy balance property was similar to those of a dry continental climate. Therefore, these results indicate that the precipitation is more intense in the windward area of the advection path of moist air, and this tendency is more pronounced in mountainous regions.
As described above, very interesting features of atmospheric condition and snowfall were revealed in Japanese Alps region created by the specific climate condition and topographic characteristic. In the situation that global warming has been reported, it could suspect that the large variation of precipitation phase will be conceived in the alpine region because it has a large spatial variation of air temperature. We would like to deepen our understanding of the seasonal snow cover in Japanese Alps region and discuss how the mountainous environment will change in the future.