Japan Geoscience Union Meeting 2014

Presentation information

Oral

Symbol A (Atmospheric, Ocean, and Environmental Sciences) » A-HW Hydrology & Water Environment

[A-HW25_2AM1] Isotope Hydrology 2014

Fri. May 2, 2014 9:00 AM - 10:45 AM 414 (4F)

Convener:*Masaya Yasuhara(Geological Survey of Japan, AIST), Kohei Kazahaya(Geological Survey of Japan, AIST), Shinji Ohsawa(Institute for Geothermal Sciences, Graduate School of Science, Kyoto University), Masaaki Takahashi(Geological Survey of Japan (GSJ), National Institute of Advanced Industrial Science and Technology (AIST)), YUICHI SUZUKI(Faculty of Geo-Environmental Sience,Rissho University), Futaba Kazama(Social Cystem Engineering, Division of Engineering, Interdiciplinary Graduate School of Medical and Engineering, University of Yamanashi), Kazuyoshi Asai(Geo Science Laboratory), Chair:Masaya Yasuhara(Geological Survey of Japan, AIST), Noritoshi Morikawa(Geological Survey of Japan, AIST)

9:30 AM - 9:45 AM

[AHW25-03] Water vapor origins in all over Japan in winter simulated by the regional isotope circulation model

*Masahiro TANOUE1, Kimpei ICHIYANAGI1, Kei YOSHIMURA2, Jun SHIMADA1 (1.Graduate School of Science and Technology, Kumamoto University, 2.Atmosphere and Sea Research Institute and Institute of Industrial Science, University of Tokyo)

Keywords:stable isotopes in precipitation, water vapor origins, regional isotope circulation model, in all over Japan

In this paper, water vapor origins in all over Japan in winter were simulated by using a regional isotope circulation model with stable isotopes in water (δ18O and δD). Precipitation and stable isotopes were simulated for the period between December to February in 2001—2010, spatial distributions of them were reproduced observations well. Simulated daily sea-level pressure patterns were divided into two types: winter monsoon (WM) type and extratropical cyclone (EC) type. In the WM type, precipitation rate was high and low along the Japan Sea side and the Pacific Ocean side, respectively. Spatial distribution of δ18O in precipitation was recognized the latitude effect (values decrease with increasing latitude) on the Pacific Ocean and the Japan Sea. Spatial distributions of d-excess (=δD-8×δ18O) in precipitation and evaporation were above 16‰ around Japan, those were extreme high (above 22‰) especially on the Pacific Ocean and the Japan Sea. Simulated water vapor evaporated from the Japan Sea was predominant in all over Japan in the WM type without southwestern islands of Japan. Interestingly, a portion of this moisture moved eastward to the Pacific Ocean, however, the moisture was not contributed to total amount of precipitation along the Pacific Ocean side because it was little precipitation. In contrast, precipitation rate was high in all over Japan in the EC type. Spatial distribution of δ18O in precipitation was recognized the latitude effect on the Pacific Ocean and the Japan Sea and the amount effect (values decrease with increasing precipitation amount) across Japan. Spatial distributions of d-excess in precipitation and evaporation were below 14‰ around Japan without the western part of the East China Sea. Simulated water vapor evaporated from the Pacific Ocean was predominant in all over Japan. Comparing δ18O and d-excess in precipitation between the WM type and the EC type, those were 2‰ and 8‰ higher along the Japan Sea side in the WM type than in the EC type, respectively.