中国科学院南海海洋研究所机构知识库
Advanced  
SCSIO OpenIR  > 热带海洋环境国家重点实验室(LTO)  > 会议论文
学科主题: Engineering, Civil; Engineering, Ocean; Engineering, Electrical & Electronic; Oceanography
题名: The shelf-edge frontal structure in the central East China Sea and its impact on low-frequency acoustic propagation
作者: Ramp, SR ; Chiu, CS ; Bahr, FL ; Qi, YQ ; Dahl, PH ; Miller, J ; Lynch, JF ; Zhang, RH ; Zhou, JX
会议文集: IEEE JOURNAL OF OCEANIC ENGINEERING
出版日期: 2004
关键词: environmental acoustics ; internal waves ; Kuroshio current ; shelf circulation
会议网址: 查看原文
收录类别: sci
ISSN: 0364-9059
部门归属: USN, Postgrad Sch, Dept Oceanog, Monterey, CA 93943 USA; S China Sea Inst Oceanol, Guangzhou, Peoples R China; Univ Washington, Appl Phys Lab, Seattle, WA 98195 USA; Univ Rhode Isl, Dept Ocean Engn, Narragansett, RI 02882 USA; Woods Hole Oceanog Inst, Woods Hole, MA 02543 USA; Chinese Acad Sci, Inst Acoust, Beijing, Peoples R China; Georgia Inst Technol, Atlanta, GA 30332 USA
项目归属: LED
摘要: Two field programs, both parts of the Asian Seas International Acoustics Experiment (ASIAEX), were carried out in the central East China Sea (28degrees to 30degreesN, 126degrees 30' to 128degreesE) during April 2000 and June 2001. The goal of these programs was to study the interactions between the shelf edge environment and acoustic propagation at a wide range of frequencies and spatial scales. The low-frequency across-slope propagation was studied using a synthesis of data collected during both years including conductivity-temperature-depth (CTD) and mooring data from 2000, and XBT, thermistor chain, and wide-band source data front 2001. The water column variability during both years was dominated by the Kuroshio Current flowing from southwest to northeast over the continental slope. The barotropic tide was a mixed diurnal/semidiurnal tide with moderate amplitude compared to other parts of the Yellow and East China Sea. A large amplitude semidiurnal internal tide was also a prominent feature of the data during both years. Bursts of high-frequency internal waves were often observed, but these took the form of internal solitons only once, when a rapid off-shelf excursion of the Kuroshio coincided with the ebbing tide. Two case studies in the acoustic transmission loss (TL) over the continental shelf and slope were performed. First, anchor station data obtained during 2000 were used to study how a Kuroshio warm filament on the shelf induced variance in the transmission loss (TL) along the seafloor in the NW quadrant of the study region. The corresponding modeled single-frequency TL structure explained the significant fine-scale variability in time primarily by the changes in the multi path/multimode interference pattern. The interference was quite sensitive to small changes in the phase differences between individual paths/modes induced by the evolution of the warm filament. Second, the across-slope sound speed sections from 2001 were used to explain the observed phenomenon of abrupt signal attenuation as the transmission range lengthened seaward across the continental shelf and slope. This abrupt signal degradation was caused by the Kuroshio frontal gradients that produced an increasingly downward-refracting sound-speed field seaward from the shelf break. This abrupt signal dropout was explained using normal mode theory and was predictable and source depth dependent. For a source located above the turning depth of the highest-order shelf-trapped mode. none of the propagating modes on the shelf were excited, causing total signal extinction on the shelf.
Citation statistics:
内容类型: 会议论文
URI标识: http://ir.scsio.ac.cn/handle/344004/5591
Appears in Collections:热带海洋环境动力学重点实验室(LED)_会议论文

Files in This Item: Download All
File Name/ File Size Content Type Version Access License
The Shelf-Edge Frontal Structure in the Central East.pdf(4363KB)----开放获取--View Download

Recommended Citation:
Ramp, SR; Chiu, CS; Bahr, FL; Qi, YQ; Dahl, PH; Miller, J; Lynch, JF; Zhang, RH; Zhou, JX.The shelf-edge frontal structure in the central East China Sea and its impact on low-frequency acoustic propagation,IEEE JOURNAL OF OCEANIC ENGINEERING,2004,29(4):1011-1031
Service
Recommend this item
Sava as my favorate item
Show this item's statistics
Export Endnote File
Google Scholar
Similar articles in Google Scholar
[Ramp, SR]'s Articles
[Chiu, CS]'s Articles
[Bahr, FL]'s Articles
CSDL cross search
Similar articles in CSDL Cross Search
[Ramp, SR]‘s Articles
[Chiu, CS]‘s Articles
[Bahr, FL]‘s Articles
Related Copyright Policies
Null
Social Bookmarking
Add to CiteULike Add to Connotea Add to Del.icio.us Add to Digg Add to Reddit
文件名: The Shelf-Edge Frontal Structure in the Central East.pdf
格式: Adobe PDF
所有评论 (0)
暂无评论
 
评注功能仅针对注册用户开放,请您登录
您对该条目有什么异议,请填写以下表单,管理员会尽快联系您。
内 容:
Email:  *
单位:
验证码:   刷新
您在IR的使用过程中有什么好的想法或者建议可以反馈给我们。
标 题:
 *
内 容:
Email:  *
验证码:   刷新

Items in IR are protected by copyright, with all rights reserved, unless otherwise indicated.

 

 

Valid XHTML 1.0!
Copyright © 2007-2017  中国科学院南海海洋研究所 - Feedback
Powered by CSpace