今天是2024年12月15日 星期日 hftc 退出

A Simple Model of the Indonesian Throughflow and Its Composition

http://www.firstlight.cn2008/12/19

[作者] Roxana C. Wajsowicz

[单位] The Institute for Low Temperature Science, Hokkaido University

[摘要] A simple analytical model of the closure of the wind-driven gyres in the tropical west Pacific is developed to illustrate the role of Halmahera and variations in the Pacific wind stress on the water mass compos…

[关键词] Indonesian Throughflow Papua New Guinea South Pacific North Pacific origin North Equatorial Countercurrent

A simple analytical model of the closure of the wind-driven gyres in the tropical west Pacific is developed to illustrate the role of Halmahera and variations in the Pacific wind stress on the water mass composition of the flow from the Pacific to the Indian Ocean through the Indonesian archipelago—that is, the Indonesian Throughflow. The model is expressed in terms of the streamfunction, , for the depth-integrated velocity field. There are three principal dynamical states, and therefore composition regimes. In the absence of Halmahera, the throughflow is composed of water wholly originating from the South Pacific (SP) if the streamfunction at the interior edge of the western boundary layer at the latitude of the northern tip of Papua New Guinea (PNG), N, is greater than that on the Asian continent, taken as zero, which is typically the situation in the Northern Hemisphere late summer. The throughflow is composed of water of wholly North Pacific origin (NP) if N A, the value of the streamfunction on Australia–PNG, which corresponds to winter conditions. The throughflow is fed by both the fresh Mindanao Current and the saltier South Equatorial Current (SEC) otherwise. If Halmahera is taken into account, the criteria determining the composition regimes are modified. Its presence results in a fresher throughflow, 30% NP–70% SP compared with 100% SP, as typically decreases northwards in the equatorial west Pacific. The result of averaging over perturbations in N, A is also considered.

Estimates of the throughflow composition from observed hydrography imply a predominantly NP source. A possible explanation is nonlinear retroflection of the SEC into the North Equatorial Countercurrent (NECC), which would lead to the throughflow being fed by the Mindanao Current for much of the year. However, the simple model predicts that a large amount of water of NP origin enters the Indonesian basins before exiting to feed the NECC, even when the throughflow is predicted to be wholly SP. Mixing within the basins would modify the composition of the NECC and throughflow. Different west Pacific states and their effect on the composition are investigated further with a flat-bottomed, homogeneous numerical general circulation model with a simplified geometry and climatological monthly mean forcing.

存档附件原文地址

原文发布时间:2008/12/19

引用本文:

Roxana C. Wajsowicz.A Simple Model of the Indonesian Throughflow and Its Compositionhttp://hftc.firstlight.cn/View.aspx?infoid=592480&cb=fanshujingxg
发布时间:2008/12/19.检索时间:2024/12/15

中国研究生教育排行榜-

正在加载...

中国学术期刊排行榜-

正在加载...

世界大学科研机构排行榜-

正在加载...

中国大学排行榜-

正在加载...

人 物-

正在加载...

课 件-

正在加载...

视听资料-

正在加载...

研招资料 -

正在加载...

知识要闻-

正在加载...

国际动态-

正在加载...

会议中心-

正在加载...

学术指南-

正在加载...

学术站点-

正在加载...