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Basic Study on the Characteristics of Energy and Water fluxes in the Alpine Region and Satellite Remote Sensing of Snow

高寒地区能量水通量特征及积雪卫星遥感基础研究

基本信息

批准号：
03452209
负责人：
KOIKE Tosio
金额：
$ 4.42万
依托单位：
Nagaoka University of Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1991
资助国家：
日本
起止时间：
1991 至 1992
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-03452209/
关键词：
cryosphere heat budget microwave remote sensing snowmelt 雪氷圏リモ-トセンシング

项目摘要

This study investugates the discrepancies of heat budgets on snow surface between in the high alpine area and in the lower-lands through the field observations. The energy exchanges across the snow surface were measured at three observation sites ; two were located at the diffrent elevations, 2950m and 3400m, on the northern slope of Mt.Fuji and the other at 300m in Niigata prefecture. Snowmelt was calculated using snow density measured by snow sampler once a week and melting depth by camera in every six hours. The role of turbulent hear flux in high alpine area was more important than in the lower-land. The latent heat flux was usually negative and the large positive latent heat flux associated with the warm, humid and strong wind sometimes caused the very intense snowmelt in the high alpine area.Microwave remote sensing techniques offer important advatages for snow mapping : the all weather capability and the possibility to detect snow water equivalent directly. However there are many factors which influence on the microwave signature of snow such as grain size, liquid water content, density and stratification. The profile of dielectric constant represents the major snow properties. The dielectric constant model was established based on the field measurements of snow using the portable dielectric probe. Furtermore the temporal and spatial distributions of the profile of the dielectric constant in two regions were identified by applying the model to the exsiting snow pit observation data.

通过野外观测，研究了高寒地区和低海拔地区雪面热量收支的差异。在富士山北坡的2950m和3400m不同海拔的两个观测点和新泻县300m的另一个观测点测量了雪面能量交换。用采雪器每周测量一次积雪密度和相机每隔6小时测量一次积雪融化深度来计算融雪量。湍流切变通量在高海拔地区的作用比在低海拔地区更为重要。高寒地区的潜热通量通常为负值，而大的正潜热通量伴随着温暖、潮湿和强风，有时会导致高寒地区非常强烈的积雪融化。微波遥感技术具有全天候的能力和直接探测雪水当量的可能性，为积雪制图提供了重要的优势。然而，影响雪微波特征的因素很多，如颗粒大小、液态水含量、密度和层结等。介电常数的分布代表了雪的主要性质。利用便携式介电探头对积雪进行了野外测量，建立了积雪的介电常数模型。并应用该模型对现有雪坑观测数据进行了识别，得到了两个地区介电常数分布的时间和空间分布。