@article{oai:nipr.repo.nii.ac.jp:00010157,
 author = {Ohmura, Atsumu and Ohmura, Atsumu},
 issue = {1},
 journal = {Polar science, Polar science},
 month = {Apr},
 note = {The total solar irradiance (TSI, or solar constant) acquired a new value: 1361 W m^<-2> instead of 1365 W m^<-2>. However a long-term variation of TSI was not detected. The solar irradiance at the earth's surface is considerably smaller (170 W^<-2>) than previously believed (e.g. 198 W m^<-2> of IPCC AR4). The previous overestimation is due to the underestimation of the absorption of solar radiation in the atmosphere. The absorption of solar radiation in the atmosphere at about 90 W m^<-2>, or 25-28% of the primary solar radiation from space. The global mean atmospheric downward terrestrial radiation is much larger (345 W m^<-2>) than previously assumed (325 W m^<-2> of IPCC AR4). The Arctic has regions of negative annual net radiation, a very rare phenomenon on the globe. These regions are the Central Arctic Ocean with its multi-year ice coverage and the accumulation area of the Greenland ice sheet. The energy balance of these regions is presented. Long-wave incoming radiation has been increasing in the Arctic at a rate of 4-5 W m^<-2>/Decade. The Greenland ice sheet exhibits a large vertical difference in net radiation from the ablation area to the dry snow zone in summer. It ranges from 80 W m^<-2> in the ablation area to 20 W m^<-2> at the equilibrium line and to 10 W m^<-2> in the dry snow zone. This gradient determines the melt gradient on the ice sheet, and is mainly caused by the altitude variation in atmospheric long-wave radiation, seconded by the albedo variation. The effect of albedo in summer for various surfaces is discussed. Simulation capabilities of radiation for many GCMs are investigated., 熱収支気候学はこの数年間に大きな進歩を経験したので、全球の新しい熱収支を、次に北極について更新されつつある熱収支を述べる。まず太陽常数は、すこし小さい1361 Wm?２を用いる。地表での全天日射は従来の値よりはるかに小さい170 Wm?２となり、大気の吸収率が遥かに大きく25から28％と推定された。大気から地表面への長波は従来の値より大幅に増加し全球平均で345 Wm?２前後となった。北極では、多年氷に覆われている北極海中央部とグリーンランド氷床の涵養域で、年平均で正味放射が負になっている。北極域の地表面への長波放射の値は、最近20年間の平均で4から5 Wm?２／10年の率で増加している。グリーンランド氷床の放射平衡は、正確に知られるようになり、北極の諸表面の主なアルベドも最新の情報を提出する。（348）},
 pages = {5--13},
 title = {Present status and variations in the Arctic energy balance},
 volume = {6},
 year = {2012}
}