2006 Fiscal Year Final Research Report Summary
Solar influence on the troposphere and oceans through stratospheric processes
| Project/Area Number |
17340143
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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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 | Nagoya University (2006)
Japan, Meteorological Research Institute (2005) |
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Principal Investigator |
KODERA Kunihiko Nagoya University, Graduate School of Environmental Studies, coe Professor, 環境学研究科COE, 特任教授 (70343887)
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| Co-Investigator(Kenkyū-buntansha) |
SHIBATA Kiyotaka Meteorological Research Institute, Atmospheric Environment and Applied Meteorology Research Department, Head, 環境応用研究部, 室長 (50354494)
KURODA Yuhji Meteorological Research Institute, Climate Research Dpt, senior Researcher, 気候研究部, 主任研究官 (80343888)
YUKIMOTO Seiji Meteorological Research Institute, Climate Research Dpt, senior Researcher, 気候研究部, 主任研究官 (90354464)
NAKAEGAWA Toshiyuki Meteorological Research Institute, Climate Research Dpt, senior Researcher, 気候研究部, 主任研究官 (20282600)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Climate change / Solar influence |
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| Research Abstract |
The purpose of the present study is to demonstrate the solar influence on the troposphere and oceans through stratospheric dynamical processes and to identify its mechanism by conducting observational analyses and numerical model experiments.
1. Atmospheric model experiments
The role of the equatorial QBO in the stratosphere and the difference of the solar impact on the troposphere according to the phase of the QBO were shown by using a Meteorological Research Institute (MRI) chemical climate model and Free University of Berlin (FUB) atmospheric general circulation model. The impact of the change of the stratospheric meridional circulation on the vertical motion of the troposphere was demonstrated by a coordinated model experiment by using the same stratospheric momentum forcings in the MRI and FUB models.
2. Coupled ocean model experiment
To understand the impact of the stratospheric circulation change due to the solar variation on the troposphere and oceans, a momentum forcing experiment is conducted using a MRI coupled ocean model. It was shown that without a change in the solar constant, globally averaged annual mean temperature can be changed about 0.5K.
3. Observational study
By using reanalysis data, the monsoon circulation over the Indian Ocean region was shown to be influenced through change in stratospheric meridional circulation due to the solar cycle. This further lead to a modulation of the relationship between the Indian Ocean Dipole mode and the El Nino/Southern Oscillation in the Pacific sector. As an example of the stratospheric impact modification of the equatorial convective activity, cirrus cloud coverage and precipitation following a stratospheric major warming were shown.
4. International cooperation
SPARC working group on the solar influence through chemical and dynamical processes (SOLARIS) was formed and its first meeting was organized with our collaborators at U.S. National Center for Atmospheric Research in October 2006.
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