• Login
    View Item 
    •   Home
    • Theses and Dissertations
    • PhD Dissertations
    • View Item
    •   Home
    • Theses and Dissertations
    • PhD Dissertations
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Browse

    All of KAUSTCommunitiesIssue DateSubmit DateThis CollectionIssue DateSubmit Date

    My Account

    Login

    Quick Links

    Open Access PolicyORCID LibguideTheses and Dissertations LibguideSubmit an Item

    Statistics

    Display statistics

    Circulation and Water Mass Formation in the Northern Red Sea Response to Wind and Thermohaline Forcing

    • CSV
    • RefMan
    • EndNote
    • BibTex
    • RefWorks
    Thumbnail
    Name:
    PhD Dissertation-Final_Lina Eyouni.pdf
    Size:
    6.606Mb
    Format:
    PDF
    Description:
    PhD Dissertation
    Download
    View more filesView fewer files
    Type
    Dissertation
    Authors
    Eyouni, Lina cc
    Advisors
    Jones, Burton cc
    Committee members
    Stenchikov, Georgiy L. cc
    Berumen, Michael L. cc
    Washburn, Libe
    Program
    Marine Science
    KAUST Department
    Biological and Environmental Science and Engineering (BESE) Division
    Date
    2021-11
    Permanent link to this record
    http://hdl.handle.net/10754/673855
    
    Metadata
    Show full item record
    Abstract
    Numerical simulation and remote sensing have indicated that the northern half of the Red Sea has a significant role in the thermohaline circulation within the basin. However, very few studies with in situ observation have been performed in a region where the formation of Red Sea Outflow Water (RSOW) and occasionally of Red Sea Deep Water (RSDW) take place during the winter in the northern Red Sea (NRS). This study provides new insights into the seasonal variability and the mechanisms that drive the thermohaline circulation of the north half Red Sea using high-resolution glider observations combined with reanalysis and satellite datasets. The study describes the water masses characteristics, the mesoscale activity, and the forcing mechanisms. In addition, we examine the biogeochemical responses to the physical drivers in the northern half of the Red Sea and how these processes alter the marine ecosystem. During winter, the mesoscale eddy activity and heat fluxes create the necessary conditions for the formation of RSOW in the NRS. The cyclonic circulation elevates relatively denser water in the surface, which is exposed to the atmosphere exchange. Thus, it leads to subduction of the surface layer forming of RSOW. The subducted water has been characterized by high oxygen as it has recently been ventilated. In addition, chlorophyll fluorescence has subducted along the isopycnals, contributing to exporting material below the sunlit layer. After the formation of RSOW, a period of strong anticyclonic circulation was observed In late February, which stirred and mixed the advected waters from the south in the northern region. It is accompanied by heat flux transition, and at the periphery of the observed Anticyclonic Eddy, an uplifting of the densest water to the surface occurred. The presence of the anticyclonic circulation enables the water advection from the south and extends the time of the surface water for atmospheric exposure. In April, the warmer intrusion of fresher waters from the south dominated the eastern part of the NRS, reestablishing the cyclonic circulation. To the best of our knowledge, this is the first in situ observation in the NRS that captured the seasonal progression of the transition of heat flux in wintertime and water advection that terminates the formation of RSOW. A continuous supply of northward warmer, lower salinity near the coast from the south is observed throughout the summertime period. Strong stratification with surface mixed layers no deeper than 25-30 meters due to the advection of lower salinity surface water and local heating. Another change that occurred during the summer period is that the source of low salinity inflow into the region transitioned from Gulf of Aden Surface Water (GASW) to Gulf of Aden Intermediate Water (GAIW)—assuming that the inflow of GAIW began with the onset of the Southwest Monsoonal winds in the south. The summertime heating and along basin evaporation set up the system for the wintertime cooling and additional evaporation that contributes to the formation of RSOW and RSDW. The mixed layer Price-Weller-Pinkel (PWP) model (Price et al., 1986) is implemented to quantify the influence of local heat fluxes compared with horizontal advection of the Gulf of Aden Water on the upper layer. Simulation of the mixed layer showed that advection was the major contributor to the seasonally integrated heat content and mixed layer simulation in summer. In contrast to winter, the timing of the mesoscale eddy activity, significant cooling, and advection add complexity to the region. The difference in the heat content was significant, and the PWP predicted an increasing mixed layer depth, while the observed mixed layer depth remained relatively constant. The differences between the calculated and simulated heat content were minimum during the absence of the mesoscale eddy and advection from the south. Overall, the quantification suggests a complex relationship between atmospheric forcing and advection on the heat content and the mixed layer depth.
    Citation
    Eyouni, L. (2021). Circulation and Water Mass Formation in the Northern Red Sea Response to Wind and Thermohaline Forcing. KAUST Research Repository. https://doi.org/10.25781/KAUST-98YQZ
    DOI
    10.25781/KAUST-98YQZ
    ae974a485f413a2113503eed53cd6c53
    10.25781/KAUST-98YQZ
    Scopus Count
    Collections
    Biological and Environmental Science and Engineering (BESE) Division; Marine Science Program; PhD Dissertations

    entitlement

     
    DSpace software copyright © 2002-2023  DuraSpace
    Quick Guide | Contact Us | KAUST University Library
    Open Repository is a service hosted by 
    Atmire NV
     

    Export search results

    The export option will allow you to export the current search results of the entered query to a file. Different formats are available for download. To export the items, click on the button corresponding with the preferred download format.

    By default, clicking on the export buttons will result in a download of the allowed maximum amount of items. For anonymous users the allowed maximum amount is 50 search results.

    To select a subset of the search results, click "Selective Export" button and make a selection of the items you want to export. The amount of items that can be exported at once is similarly restricted as the full export.

    After making a selection, click one of the export format buttons. The amount of items that will be exported is indicated in the bubble next to export format.