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Local and remote responses to excessive snow mass over Eurasia appearing in the northern spring and summer climate–a study with the MRI GCM (1991)
| Venue: | Journal of the Meteorological Society of Japan |
| Citations: | 22 - 0 self |
BibTeX
@ARTICLE{Yasunari91localand,
author = {Tetsuzo Yasunari and Akio Kitoh and Tatsushi Tokioka},
title = {Local and remote responses to excessive snow mass over Eurasia appearing in the northern spring and summer climate–a study with the MRI GCM},
journal = {Journal of the Meteorological Society of Japan},
year = {1991}
}
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Abstract
The effect of excessive snow mass over the Eurasian continent on the spring and summer climate is investigated by using the MRI * GCM. The ensemble mean of the four runs (SNOW runs) with the excessive snow mass of 5 cm (water equivalent) at the beginning of March over the snow cover area of the continent is compared with that of the control runs, to deduce the effect of the snow mass on the climatic parameters in the later seasons. The main results are summarized as follows: (1) In spring, the albedo effect is dominated in the lower latitudes particularly over the Tibetan Plateau. The reduced net radiation by the anomalous snow cover balances the reduced surface sensible and latent heat fluxes, which account for the significant decrease ofsurface temperature, cloudiness and total diabatic heating over there in the SNOW runs. (2) In summer, in contrast, he snow-hydrological effect is significant, particularly in the mid-latitudes. The increase of ground wetness inthe SNOW runs causes anomalous cooling and higher pressure near the surface. A moderate signal of the weakened Asian summer monsoon is also obtained. However, the increase of evaporation activates cumulus convection, which partly compensates forthe decrease of total diabatic heating by the cooling near the surface. This evaporation/convection feedback seems to work, on the other hand, to sustain the increased ground wetness throughout the summer. (3) The atmospheric teleconnection patterns induced by the anomalous snow cover over the Tibetan Plateau and east Asia significantly appear over the north Pacific and the North American continent in spring through late summer. These anomalous circulations cause the considerable d crease ofsurface temperature over the northeastern part of North America. (4) The implication of these results for the Ice Age issue is also briefly discussed. 1.
Keyphrases
mri gcm snow mass remote response northern spring tibetan plateau anomalous snow cover total diabatic heating excessive snow mass late summer north america main result summer climate later season north pacific anomalous circulation evaporation activates cumulus convection north american continent weakened asian summer monsoon albedo effect significant decrease ofsurface temperature ensemble mean reduced surface snow-hydrological effect evaporation convection feedback northeastern part eurasian continent snow cover area ice age issue inthe snow reduced net radiation atmospheric teleconnection pattern latent heat flux ground wetness east asia considerable crease ofsurface temperature forthe decrease climatic parameter water equivalent moderate signal
