Submesoscale Dynamics in the Northern Gulf of Mexico. Part II: Temperature–Salinity Relations and Cross-Shelf Transport Processes

Author:

Barkan Roy1,McWilliams James C.1,Molemaker M. Jeroen1,Choi Jun2,Srinivasan Kaushik1,Shchepetkin Alexander F.1,Bracco Annalisa2

Affiliation:

1. Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, Los Angeles, California

2. School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia

Abstract

AbstractThis paper, the second of three, investigates submesoscale dynamics in the northern Gulf of Mexico under the influence of the Mississippi–Atchafalaya River system, using numerical simulations at 500-m horizontal resolution with climatological atmospheric forcing. The Turner angle Tu, a measure of the relative effect of temperature and salinity on density, is examined with respect to submesoscale current generation in runs with and without riverine forcing. Surface Tu probability density functions in solutions including rivers show a temperature-dominated signal offshore, associated with Loop Current water, and a nearshore salinity-dominated signal, associated with fresh river water, without a clear compensating signal, as often found instead in the ocean’s mixed layer. The corresponding probability distribution functions in the absence of rivers differ, illustrating the key role played by the freshwater output in determining temperature–salinity distributions in the northern Gulf of Mexico during both winter and summer. A quantity referred to as temperature–salinity covariance is proposed to determine what fraction of the available potential energy that is released during the generation of submesoscale circulations leads to the destruction of density gradients while leaving spice gradients untouched, thereby leading to compensation. It is shown that the fresh river fronts to the east of the Bird’s Foot can evolve toward compensation in concert with a gradual release of available potential energy. It is further demonstrated that, during winter, the cross-shelf freshwater transport mechanism to the west of the Bird’s Foot is well approximated by a diffusive process, whereas to the east is better represented by a ballistic process associated with the Mississippi water that converges in a jetlike pattern.

Funder

Gulf of Mexico Research Initiative

Office of Naval Research

Publisher

American Meteorological Society

Subject

Oceanography

Reference24 articles.

1. The Hamburg Ocean Atmosphere Parameters and Fluxes from Satellite Data—HOAPS-3;Andersson;Earth Syst. Sci. Data,2010

2. Submesoscale dynamics in the northern Gulf of Mexico. Part I: Regional and seasonal characterization and the role of river outflow;Barkan;J. Phys. Oceanogr.,2017

3. Submesoscale dynamics in the northern Gulf of Mexico. Part III: Lagrangian implications;Choi;J. Phys. Oceanogr.,2017

4. On the development of thermohaline correlations as a result of nonlinear diffusive parameterizations;Ferrari;J. Mar. Res.,1997

5. Thermohaline variability in the upper ocean;Ferrari;J. Geophys. Res.,2000

Cited by 25 articles. 订阅此论文施引文献 订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3