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北海道大学水産科学研究彙報 = Bulletin of Fisheries Sciences, Hokkaido University >
第65巻 第1号 >
小笠原諸島周辺海域における海洋構造の季節変化
Title: | 小笠原諸島周辺海域における海洋構造の季節変化 |
Other Titles: | Seasonal variations of the hydrographic structure around the Ogasawara islands |
Authors: | 藤原, 将平1 Browse this author | 磯田, 豊2 Browse this author →KAKEN DB | 妹尾, 浩太郎3 Browse this author | 高木, 省吾4 Browse this author →KAKEN DB |
Authors(alt): | Fujiwara, Shohei1 | Isoda, Yutaka2 | Senoo, Kotaro3 | Takagi, Shogo4 |
Keywords: | Izu-Ogasawara ridge | hydrographic data | seasonal variations | impinging |
Issue Date: | 16-Mar-2015 |
Publisher: | 北海道大学大学院水産科学研究院 |
Journal Title: | 北海道大学水産科学研究彙報 |
Volume: | 65 |
Issue: | 1 |
Start Page: | 1 |
End Page: | 15 |
Abstract: | Using a two-layer model driven by the annual change in wind stress, Isobe and Imawaki (2002) suggested that the topographic effect of Izu-Ogasawara Ridge generates the baroclinic activity through the impinging process due to the barotropic response over the bottom slope, but there is no observed evidence for such process. To seek the indirect evidence of the impinging process in this study, seasonal variations of isopycnic vertical displacement over the ridge are investigated through analysis of monthly sea level at Chichijima and hydrographic data around the Ogasawara islands. Although annual signals of sea level and density field were largely masked by the westward propagating synoptic eddies with several-month time scale, we could detect annual cycle of isopycnic surfaces around the permanent pycnocline out of phase with that of sea surface mixed layer, i.e., it moves downward in summer (May to July) and upward in winter (November to January). Furthermore, this annual cycle was relatively amplified along the eastern hydrographic line at the intruding side of westward propagating barotropic waves. These results indirectly support the seasonal occurrence of impinging over the ridge. |
Type: | bulletin (article) |
URI: | http://hdl.handle.net/2115/58036 |
Appears in Collections: | 北海道大学水産科学研究彙報 = Bulletin of Fisheries Sciences, Hokkaido University > 第65巻 第1号
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