| Project/Area Number |
08640541
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Tohoku University |
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Principal Investigator |
YAMAZAKI Takeshi Tohoku Univ.Science Associate Prof., 大学院・理学研究科, 助教授 (80220317)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUSHIMA Dai Tohoku Univ.Science Research associate, 大学院・理学研究科, 助手 (50250668)
YASUDA Nobuhisa Tohoku Univ.Science Professor, 大学院・理学研究科, 教授 (30004419)
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| Project Period (FY) |
1996 – 1997
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| Project Status |
Completed (Fiscal Year 1997)
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| Budget Amount *help |
¥2,200,000 (Direct Cost: ¥2,200,000)
Fiscal Year 1997: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1996: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | forest / albedo / heat budget / crown snow / frost depth / spectrum / radiometric temperatur / snowfall amount / 着雪 |
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| Research Abstract |
Following are results of measurements of albedo and snowfall at a forest in Morioka, Iwate Prefecture. Albedo of forest without crown snow becomes large with increasing solar zenith angle and becomes small with increasing cloud amount. Moreover, it increases with the increase of crown-snow ratio, but its relationship is nonlinear. After snowfall the crown-snow ratio decreases exponentially. The amount of crown-intercepted snow is large in dense evergreen forest, while there is no difference among deciduous forests.
Dependency of frost depth on meteorological conditions and on soil parameters has been investigated after the calculation of soil temperature. Moreover, we investigated the influence of snow cover and forest on the frost depth. The result is that the frost depth is sensitive to snow depth and thermal property of snow, and not sensitive to soil water content and forest density.
We proposed a method to obtain the imformation about snow cover and forest density using visible and near infrared radiation band data. It is a result of spectral measurement with potted young trees and model calculations. Furthermore, a proper method for estimating sensible heat flux was proposed, which is using radiometric temperature measured at optimum viewing angle. This method was validated at a rice paddy field in Kogota, Miyagi Prefecture.
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