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第 180 回 大気海洋物理学・気候力学セミナー のおしらせ

日 時: 4月 24日(木) 午前 09:30
場 所: 環境科学院 2階 講堂

発表者:上原 裕樹 (環オホーツク研究センター PD研究員)
題 目:Estimation of heat and freshwater transports in the North Pacific using the high resolution XBT data.

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Estimation of heat and freshwater transports in the North Pacific using the high resolution XBT data. (上原 裕樹) 発表要旨 :

 The mean heat and freshwater transports in the North Pacific subtropical 
 gyre during 1998-2002 are estimated. High-resolution expendable 
 bathythermograph/expendable conductivity-temperature-depth (XBT/XCTD) 
 transects (PX-40, Honolulu to Japan; PX-37, San Francisco to Honolulu; 
 PX-10, Honolulu to Guam; PX-44, Guam to Taiwan/Hong Kong) are used to 
 calculate geostrophic transport across each of the ship tracks. Ekman 
 transport is estimated from satellite-scatterometer wind stress. The 
 mean heat and freshwater transport convergences into the northern box 
 bounded by the PX-40/37 transects and the Tsushima and Bering Straits 
 are 0.26 +/- 0.16 pW (pW = 10(15) W) and -0.26 +/- 0.11 Sv (Sv = 10(6) 
 m(3)/s), respectively. Heat and freshwater transport convergences into 
 the western box bounded by the PX-40/10/44 transects and the Tsushima 
 Strait are estimated to be 0.32 +/- 0.17 pW and 0.08 +/- 0.07 Sv, 
 respectively. In both boxes, warmer waters transported inward by the 
 Ekman flow and by the Kuroshio are compensated by the export of waters 
 at cooler temperatures, whose peaks are found in the temperatures of the 
 mode waters formed in the North Pacific. The salt budget is also 
 described to consider the mechanisms of freshwater transport. Since the 
 western box includes the region with the strongest heat loss to the 
 atmosphere and is possibly a key region for climatic decadal variation, 
 it is necessary to continue the high-resolution XBT/XCTD measurement and 
 to make an effort at improving the estimation of heat and freshwater 
 transports in order to contribute to advancing climate studies. 
   

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連絡先

川島 正行 @北海道大学低温科学研究所
寒冷海洋圏科学部門 雲科学分野
mail-to:kawasima@lowtem.hokudai.ac.jp / Tel: 011-706-6885