2000 Fiscal Year Final Research Report Summary
Recent changes of the general circulation in the stratosphere, and its relation to the tropospheric general circulation
| Project/Area Number |
10640425
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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 | KYUSHU UNIVERSITY |
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Principal Investigator |
MIYOSHI Yasunobu KYUSHU UNIVERSITY Faculty of Science, Ass. Prof., 大学院・理学研究院, 助教授 (20243884)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAJIMA Kensuke KYUSHU UNIVERSITY Faculty of Science, Ass., 大学院・理学研究院, 助手 (10192668)
MIYAHARA Saburo KYUSHU UNIVERSITY Faculty of Science, Prof., 大学院・理学研究院, 教授 (70037282)
HIROOKA Toshihiko KYUSHU UNIVERSITY Faculty of Science, Prof., 大学院・理学研究院, 教授 (90253393)
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| Project Period (FY) |
1998 – 2000
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| Keywords | general circulation / stratosphere / ozone depletion / general circulation model / satellite data |
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| Research Abstract |
Recent changes of the general circulation in the stratosphere and the troposphere are investigated by satellite data analyses and numerical simulation. Zonal-mean differences of the temperature and zonal wind for March between 1990s and 1980s are firstly examined on the basis of stratospheric analyses of the UK Meteorological Office. We can see a cooling of order 10K in the North polar lower stratosphere and a warming of order 10K in the North polar upper stratosphere. The corresponding intensification of the polar night jet of order 15 m/s is also seen in high latitudes. These tendencies are considered to be due to the ozone depletion in 1990s.
In order to investigate effects of ozone depletion on the general circulation, numerical simulation by using a general circulation model is performed. In Arctic ozone depletion experiment, a cooling in the North polar lower stratosphere and a warming in the North polar upper stratosphere are obtained. The cooling brings about the intensification of the polar night jet. These changes are consistent with observations. The cooling is caused by the decrease of solar UV heating due to the ozone depletion, while the warming is caused by adiabatic heating due to the enhancement of downward motion. In subsequent studies, further experiments are required to exclude the contamination of stratospheric sudden warming s occurring in the experiments.
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