2006 Fiscal Year Final Research Report Summary
Influence of changes in Pacific Gateways on ENSO and monsoon
| Project/Area Number |
17540420
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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 | Meteorological Research Institute, Japan Meteorological Agency |
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Principal Investigator |
MOTOI Tatsuo Meteorological Research Institute, Oceanographic Research Department, Head of the 1^<st> Research, 海洋研究部, 室長 (90391226)
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| Co-Investigator(Kenkyū-buntansha) |
KITOH Akio Meteorological Research Institute, Climate Research Department, Head of the 1^<st> Research, 気候研究部, 室長 (50354452)
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| Project Period (FY) |
2005 – 2006
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| Keywords | Pale climate / Pale oceanography / Ocean Gateways / El Nino / Southern Oscillation / Monsoon |
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| Research Abstract |
The effect of the marine continent appeared in the Indonesian Seaway on ENSO is investigated. It is found that La Nina like condition with intensified walker circulation is induced by the appearance of the continent. The influence of the closure of the Panamanian Gateway on climate is also investigated by analyzing the data from sensitivity experiment using a coupled ocean-atmosphere general circulation model with an open and closed gateway. In the case of closed gateway, the lack of saline water transport from the Atlantic to the Pacific induces halocline formation over the sub arctic Pacific with cold climate.
The impacts of mountain uplift on freshwater discharge from the East Asian rivers and on salinity in the western North Pacific marginal seas are investigated by data analysis of climate model sensitivity experiments. As mountain becomes higher, summer monsoon is intensified and freshwater discharge from the major East Asian rivers increases, which results in decrease of annual mean salinity and enhancement of salinity seasonal variations in the East Asian marginal seas. The ENSO becomes weaker, shorter and less periodic in the model with progressive mountain uplift.
These results are generally consistent with pale oceanographic and pale climatic estimates related to the changes in the Pacific Gateways (Indonesian Seaway and Panamanian Gateway) and to the uplift of Tibetan Plateau.
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Research Products
(3 results)
