2024-03-29T12:09:02Z
https://tsukuba.repo.nii.ac.jp/oai
oai:tsukuba.repo.nii.ac.jp:00011045
2023-05-02T01:44:23Z
3:233:254
Modeling the thermal and hydrological impacts of frozen ground on the climate system
高田, 久美子
43042
Takata, Kumiko
筑波大学
University of Tsukuba
博士(理学)
Doctor of Philosophy in Science
The thermal and hydrological impacts of frozen ground in the climate system are investigated using an atmospheric general circulation model(AGCM)and a one-dimensional land-surface model. The AGCM experiments are performed with and without the soil freezing,i.e.,including and excluding the latent heat of fusion and impermeability of frozen soil. The inclusion of soil freezing leads to higher surface temperature in summer in mid-and high-latitudes over the land. This leads to larger water vapor fluxes and associated precipitation induced by stronger summer monsoons. The higher temperature over the land in summer results from the smaller evaporation caused by the smaller surface soil moisture.The small surface soil moisture is caused by the additional runoff in spring due to impermeability of frozen soils and the small available soil liquid water due to underlying frozen ground. The positive temperature anomaly is large in the regions where the potential evaporation is large even if the negative soil moisture anomaly is small,and vice versa.Moreover,the precipitation is smaller in the middle of the continent,owing to the smaller evaporation there. In winter,although the deep soil temperature in frozen ground ergions is figher with the soil freezing than without due to latent heat of fusion,the surface temperature anomaly is more likely to be governed by the atmospheric dynamical responses.Consequently,the frozen ground has the impacts on the continental scale climate.Nevertheless,the land-surface model used in the AGCM is so simple that the reproductivity of the land-surface processes and the magnitude of the frozen ground impact may be different with respect to the schemes and parameters of the soil model.
Then ...
1997
doctoral thesis
1998
1998-03-23
application/pdf
application/pdf
乙第1394号
https://tsukuba.repo.nii.ac.jp/record/11045/files/B1394.pdf
https://tsukuba.repo.nii.ac.jp/record/11045/files/1.pdf
jpn
open access