OS53A-2000
Thermal environment downscaling under the climate chenage in Seto-Inland Sea of Japan
Friday, 18 December 2015
Poster Hall (Moscone South)
Yuki Imai1, Nobuhito Mori2, Junichi Ninomiya3, Tomohiro Yasuda2 and Hajime Mase1, (1)Disaster Prevention Research Institute, Kyoto University, Kyoto, Japan, (2)Kyoto University, Kyoto, Japan, (3)Kanazawa University, Kanazawa, Japan
Abstract:
There are many studies have been conducted to project future change and assess the impacts. The latest IPCC AR5 WGI reports that there are many impact assessments of large scale changes in coastal and ocean environments but few studies on regional scale changes. We analyzed global and regional near-sea surface physical changes based on the Coupled Model Intercomparison Project Phase 5 (CMIP5) data. The downscaling of regional ocean targeting the semi-enclosed Seto-Inland Sea of Japan by Regional Ocean Modeling System (ROMS) considering the results of CMIP5. We analyzed the future projection of thermal environmental changes of the Seto-Inland Sea based on the downscaling results.
- Regional analysis of CMIP5
Analysis of CMIP5 was conducted for the historical climate and future climate at the end of 21st century considering two different emission scenarios (RCP4.5 and RCP8.5). All available 61 GCMs in CMIP5 were considered for analysis and the future changes of 11 atmospheric and oceanic variables were computed in detail. Spatial distribution of sea surface temperature (SST) showed a consistent increase overall, with local non-homogeneity. For example, an increase SST more than 4 degrees in the Northwest Pacific against to global mean SST increase of 2.6 degrees.
- The projection of the Seto-Inland Sea environment
Dynamical downscaling for Seto-Inland Sea was calculated for the year 2093 forcing future changes from CMIP5 analysis results to project future regional environmental changes in West-Japan. The results of hindcast were compared with observed results and future climate conditions were added to hindcast results.
The SST shows a remarkable increase of about 3.6 degrees in the summer but it is less in the future winter. The major change of water temperature change is increasing trend in upper 20m layer, and thermal e-folding depth in the future climate becomes shallower. The warming tendency decreases with depth in shallow water region but is different in deep water.
CMIP5 analysis projected an inhomogeneous spatial distribution of SST future change.
Using ROMS with forcing from CMIP5 analysis, we project an SST increase of 3.6 degrees in the summer. In winter the future change trend of water profile different between shallow water and deep water.
