日本東方海域における海洋深層循環の解明

阐明日本东部海域的深海环流

• 批准号: 13740277
• 负责人: 藤尾 伸三
• 金额: $ 1.34万
• 依托单位: The University of Tokyo
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2001
• 资助国家: 日本
• 起止时间: 2001 至 2002
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-13740277/
• 关键词: 伊豆小笠原海溝; 深層流; 北太平洋; 深層循環

日本列島の東に連なる伊豆小笠原海溝や日本海溝には,西側斜面を南下,東側斜面を北上する深層流がある.北上流は特に流量が大きく,北太平洋の物質輸送や熱輸送に大きな影響を持っていると考えられることから,その輸送などについて観測・解析を行った.本年度の成果は以下の通り:(1)白鳳丸KH-02-3次航海において,鹿島沖測線で5系の係留系の設置とCTD観測を行った.測線は伊豆小笠原海溝と日本海溝の接点にあたる鞍部にあたり,海溝間の海水交換を定量的に調べるためである.CTDデータの予備的な解析から,2000dbを基準とする地衡流は深層ではほぼ全域で南西向きであり,従来の東西斜面を逆行する1対の深層流と様相が大きく異なる.正味の北上流量を予想していたが,鞍部の東海底上にもっとも低温・高塩分・高酸素な水があることから,南より深層水の供給も予想され,今後とも流速計データなどの解析を進めたい.(2)伊豆小笠原海溝とその東方海洋底部分の深層流について,白鳳丸KH-00-4次航海で実施したCTDと係留流速計データの解析を行った.CTDの地衡流シアは部分的な測定ではあるが,流速計のプロファイルと一致する.CTD測線と伊豆小笠原海嶺で囲まれる部分の流量収支を計算すると,2000dbを無流面に取る場合,大きな残差が生じる.一方,海溝の中央部で流速が0になると仮定して,基準流速を与えると,西斜面の南下流は8Sv程度である.東斜面では北緯32度付近で10Svの西向きの流入があり,北緯34度付近で同量の流出がある.10Svは斜面に沿って北上すると思われるが,流量残差が10Svあり,推定誤差も大きい

Japan Islands East Link Izu Ogasawara Trench West slope South, East slope North deep current The northward flow has a large flux, and the material transport and heat transport in the North Pacific Ocean have a large impact on the stability of the flow. The achievements of this year are as follows:(1) Shirabongmaru KH-02-3 times navigation, Kashima survey line, 5 series of mooring system settings and CTD survey. The survey line is located at the junction of Izu Ogasawara Trench and Japan Trench. The sea water exchange between the trenches is quantitatively adjusted. The CTD is prepared for analysis. The 2000db reference line is located at the bottom of the trench. The flow rate in the north is expected to increase, and the flow rate in the south is expected to increase, and the flow rate in the north is expected to increase. (2)The analysis of CTD mooring current meter data was carried out on the Izu Ogasawara Trench at the bottom of the eastern ocean. The measurement of CTD geostatic current at the bottom of the ocean was consistent. The calculation of CTD measurement line and flow rate at the Izu Ogasawara Ridge was carried out at 2000db without flow surface. On one side, the velocity in the center of the trench is 0 Sv, the reference velocity is 0 Sv, and the west slope is 8Sv. East slope is near latitude 32 degrees, west direction is near latitude 34 degrees, same amount of outflow is near latitude 32 degrees, west direction is near latitude 34 degrees, west direction is near latitude 34 degrees, east slope is near latitude 32 degrees, west direction is near latitude 34 degrees, west direction is near latitude 34 degrees, east slope is near latitude 32 degrees, west direction is near latitude 34 degrees, east slope is near latitude 34 degrees, west direction is near latitude 34 degrees, east slope is near latitude 32 degrees, west direction is near latitude 34 degrees, west direction is near latitude 34 degrees, east slope is near latitude 32 degrees, west direction is near latitude 34 degrees, west direction is near latitude