2013 Fiscal Year Final Research Report
Development of a cumulus parameterization scheme based on a new static stability criterion
| Project/Area Number |
23540520
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Research Field |
Meteorology/Physical oceanography/Hydrology
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| Research Institution | Japan Agency for Marine-Earth Science and Technology |
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Principal Investigator |
NAKAMURA Kozo 独立行政法人海洋研究開発機構, 地球環境変動領域, チームリーダー (20143547)
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| Project Period (FY) |
2011 – 2013
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| Keywords | 静的安定性 / 条件付き不安定成層 / パーセル法 / 積雲境界層 / 雲解像モデル / 積雲対流パラメタリゼーション / LES |
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| Research Abstract |
The purpose of this work is to investigate the validity of the stability theory of a saturated air parcel in an unsaturated environment in terms of the moist adiabatic lapse rate of virtual temperature using observational data and numerical experiments data, and to develop a new parameterization scheme of cumulus convection. Observational results show a good agreement with the theory.
For the numerical experiment, we consider a cumulus boundary layer maintained by the balance between the surface heat fluxes, horizontal advection, and large-scale subsidence. Even if the external forcing is fixed, there occur two balanced states. One is the state with organized convection and the other is the state with randomly distributed non-organized convection. The characteristics of the boundary layer such as vertical gradient of temperature is different between the two states. In order to investigate the stability of convection, we must consider the difference between the two states.
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