西北大西洋與太平洋環流研究

Understanding Circulation Processes in Western Atlantic and Pacific Marginal Seas

張育綾(Yu-Lin Chang)

指導教授 ： 吳朝榮

國立臺灣師範大學/理學院/地球科學系/博士(2011年)

摘要

西北太平洋與大西洋邊緣海有著世界上最具能量的海流。 本研究旨在於利用模式與觀測的數值分析來了解西北大西洋與太平洋的動力過程。西北太平洋鄉會著重於墨西哥灣，藉由風驅動下的物質與熱量平衡，我們發展了一套理論來解是墨西哥套流產生不同週期渦旋的原因，上下層海洋之間的耦和與交互作用。在應用上，本研究模擬墨西哥灣在2010年發生了嚴重的漏油事件。
在西北太平洋的研究上，首先研究在風作用在強流的渦度場下產生的小尺度垂直運動，並將此應用在東海陸棚邊緣的黑潮。 利用29年的潮位站與衛星風場與高度場資料來分析黑潮過去的季節與年際變化，結果發現黑潮的流量變化與副熱帶反流所產生的渦旋有密切的關係。西北太平洋的風的震盪影響了黑潮流量變化、渦旋產生的年紀變化。此震盪在此定義為"菲律賓-台灣震盪"，我們認為此振盪可以為西北太平洋年際變化的動力連結。

關鍵字

黑潮 ； 墨西哥灣 ； 套流 ； 渦旋

並列摘要

The western margins of the North Atlantic and North Pacific Oceans have some of the most energetic currents of the world’s ocean. The goal of my study is to use model and observational data analyses to understand dynamical processes in the western North Atlantic and North Pacific marginal seas. In the western North Atlantic Ocean, I will focus on Loop Current and rings in the Gulf of Mexico. By examining mass and heat balances forced by wind, we have developed an underlying theoretical basis for explaining why the Loop Current sheds rings at irregular intervals, how these powerful upper-layer features interact with and are coupled to the deep-layer flows (deeper than 1000 m below the surface), and how, as a corollary, they may produce seasonal and inter-annual variations in the frequency of eddy-shedding. On the more practical side, during the course of my Gulf of Mexico study, the 2010 Oil Spill occurred; I will therefore present also an ensemble, long-term (weeks~months) projection of the simulated spill using Lagrangian particles. In the western North Pacific Ocean, I will study in some details how small-scale (~1
km and less) vertical motions in the ocean can be produced by wind acting on a strong current’s vorticity field, and apply that idea to upwelling at the inshore edge of the Kuroshio in East China Sea. I will then use tide-gauge, wind and satellite data to examine effects on the Kuroshio transport of the Subtropical Counter Current eddies. I then expand upon that idea to put forth the so called “Philippines-Taiwan Oscillation” which we think serves as the dynamical link for explaining a wide range of interannual variability of the western North Pacific from the tropics to subtropics.

並列關鍵字

Kuroshio ； Gulf of Mexico ； Loop Current ； eddy

參考文獻

Allen, J.S. and P.A. Newberger, 1996: Downwelling circulation on the Oregon continental shelf, part I:

response to idealized forcing, J. Phys. Oceanogr., 26, 2011 – 2035.

Anderson, D. L. T., and A. E. Gill, 1979: Beta dispersion of inertial waves. J. Geophys. Res., 84,

1836–1842.

Berntsen, J. and L.-Y. Oey, 2010: Estimation of the internal pressure gradient in σ-coordinate ocean