九州南方での水温前線の北上に伴う水温・流速変動

Translated title of the contribution: Variation of Temperature and Velocity associated with Northward Migration of the Temperature Front South of Kyushu, Japan

斉藤 勉, 秋山 秀樹, 今脇 資郎, 市川 香, 奥野 章, 瀬藤 聡, 馬谷 紳一郎, 田中 耕治, Saito Tsutomu, Akiyama Hideki, Imawaki Shiro, Ichikawa Kaoru, Okuno Akira, Setou Takashi, Umatani Shin-ichiro, Tanaka Koji, 水産総合研究センター中央水産研究所:九州大学大学院総合理工学府, 水産総合研究センター中央水産研究所, 九州大学応用力学研究所, 海洋研究開発機構水産総合研究センター中央水産研究所, 水産総合研究センター中央水産研究所, 九州大学応用力学研究所, 鹿児島県水産技術開発センター, Research Institute of Fisheries Science Fisheries Research Agency:Interdisciplinary Graduate School of Engineering Science Kyushu University National, Research Institute of Fisheries Science Fisheries Research Agency National, Institute for Applied Mechanics Kyushu University Research, Agency for Marine-Earth Science and Technology Japan, Research Institute of Fisheries Science Fisheries Research Agency National, Research Institute of Fisheries Science Fisheries Research Agency National, Institute for Applied Mechanics Kyushu University Research, Prefectural Fisheries Technology and Development Center Kagoshima

Research output: Contribution to journalArticlepeer-review

Abstract

九州南方において黒潮に伴う水温前線が20日程度の周期で繰り返し北上する現象を,はじめて三次元的かつ時間発展的に記述することを試みた。2000~2003年に実施した計6回の三次元的で密な観測で得た水温・流速のデータおよび中之島での水位データを,観測時の前線位置を指標として並べ替え,その妥当性を他の期間に連続して得られた衛星海面水温画像の時系列および中之島での水位データによって検証した上で,現象の三次元的な時間発展を調べた。その結果,水温前線の北上は,薩摩半島南方の大陸棚斜面上に形成された300m深に及ぶ構造をもつ高気圧性の黒潮前線渦(暖水舌)が,北東方向に移動して消滅する過程の一側面であることが分かった。The surface temperature front off the southern coast of Kyushu is known to migrate northward repeatedly, having about 20 day cycles. Its features, however, are known only fragmentarily. We try to describe the time evolution of the front in the three-dimensional way. We carried out three-dimensional dense observations about temperature and velocity six times in 2000-2003. The observations are rearranged to give a sequence of temperature and velocity fields which describes the evolution of the front, by using the north-south position of the front as an index. The rearrangement is justified by comparing with successive satellite images of sea surface temperature obtained in a different period. The sequence of temperature and velocity fields shows that northward migration of the temperature front is an aspect of the formation, development and dissipation of an anticyclonic Kuroshio frontal eddy on the continental slope south of Satsuma Peninsula; the frontal eddy extends down to the 300 m depth.
Translated title of the contributionVariation of Temperature and Velocity associated with Northward Migration of the Temperature Front South of Kyushu, Japan
Original languageJapanese
Pages (from-to)163-178
Number of pages16
Journal海の研究
Volume17
Issue number3
Publication statusPublished - May 5 2008

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