| Project/Area Number |
09680498
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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 |
Environmental dynamic analysis
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| Research Institution | HOKKAIDO UNIVERSITY |
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Principal Investigator |
KAWAMURA Toshiyuki Hokkaido Univ., Inst.Low Temperature Sci., Assistant Pro., 低温科学研究所, 助手 (50091434)
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| Co-Investigator(Kenkyū-buntansha) |
OHSHIMA Keiichiro Hokkaido Univ., Inst.of Low Temperature Sci., Asso.Pro., 低温科学研究所, 助教授 (30185251)
SHIRASAWA Kunio Hokkaido Univ., Inst.of Low Temperature Sci., Asso.Pro., 低温科学研究所, 助教授 (50196622)
ISHIKAWA Nobuyoshi Hokkaido Univ., Inst.of Low Temperature Sci., Asso.Pro., 低温科学研究所, 助教授 (70002277)
ENOMOTO Hiroyuki Kitami Inst.Technol., Fac.of Eng., Pro., 工学部, 教授 (00213562)
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| Project Period (FY) |
1997 – 1999
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| Keywords | sea ice / snow cover / sea ice growth processes / sea ice structure / air-sea-interaction / heat budget / surface melting / microwave radiometer |
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| Research Abstract |
Antarctic sea ice studies suggest snow cover significantly contributes to and relates with sea ice growth. The following studies were conducted to solve growth processes found near Syowa Station with deep snow cover and to inspect its generality.
(A) Studies on physical and structure properties and growth processes of sea ice :
Ice and snow samples were collected and analyzed, especially, for a long time in the Sea of Okhotsk and Lake Saroma since 1995 and frequently in the Baltic Sea in 1999. Laboratory study with tank was carried out to reproduce the growth processes. The results shows that the snow contribution was estimated at 8 and 2-26 % of total ice thickness in the Sea of Okhotsk and the Baltic Sea, respectively. Superimposed ice, which grows from refreezing of snow meltwater, was found in the Ross Sea ice samples.
(B) Studies on radiation properties of sea ice :
Field observations were carried out to investigate dependency of radiation properties, such as reflection, transmission, absorption and emission, on sea ice thickness and structure in the Lake Saroma and the Baltic Sea in the both growth and decay seasons. The optical properties were also examined under controlled conditions in a cold laboratory. The results show differences of the radiation properties between the Baltic and Saroma sea ice. They suggest these differences are caused by the difference of sea ice structure such as bubble volume and grain size.
(C) Estimation of amounts related with sea ice and snow cover from satellite data :
A new sea ice classification algorithm has been developed using a airborne microwave radiometer. It becomes clear that this algorithm is useful to classify sea ice types using a parameter related with the dielectric properties of two channels. Sea ice thickness and snow depth were also estimated from the parameter.
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