Integrated Marine Information System (IMIS)

Data Policy
Persons | Institutes | Publications | Projects | Datasets
[ report an error in this record ]basket (0): add | show Print this page
Anti-cyclonic circulation driven by the estuarine circulation in a gulf type ROFI
Fujiwara, T.; Sanford, L.P.; Nakatsuji, K.; Sugiyama, Y. (1997). Anti-cyclonic circulation driven by the estuarine circulation in a gulf type ROFI. J. Mar. Syst. 12(1-4): 83-99. https://dx.doi.org/10.1016/S0924-7963(96)00090-5
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573
Also appears in:
Ruddick, K. (1997). Processes in regions of freshwater influence (PROFILE): selected papers from the 27th International Liège Colloquium on Ocean Hydrodynamics, held in Liège, Belgium, on May 8-12, 1995. Journal of Marine Systems, 12(1-4). Elsevier: The Netherlands. 1-326 pp., more
Peer reviewed article  
Available in  Authors 
Keywords
    Estuarine circulation
    Motion > Anticyclonic motion
    Motion > Water motion > Circulation > Water circulation > Ocean circulation > Gyres
    Motion > Water motion > Circulation > Water circulation > Shelf dynamics > Estuarine dynamics
    Motion > Water motion > Vertical water movement > Upwelling
    Marine/Coastal; Fresh water
Authors  Top 
  • Fujiwara, T.
  • Sanford, L.P.
  • Nakatsuji, K.
  • Sugiyama, Y.
Abstract
    Baroclinic residual circulation processes are examined in gulf type Regions Of Freshwater Influence (ROFIs), which have large rivers discharging into a rounded head wider than the Rossby internal deformation radius. Theoretical and observational investigations concentrate on Ise Bay, Japan, with supporting data from Osaka Bay and Tokyo Bay. Simplified analytical solutions are derived to describe the primary features of the circulation. Three dimensional residual current data collected using moored current meters and shipboard acoustic doppler current profilers (ADCPs), satellite imagery and density structure data observed using STDs, are presented for comparison to the theoretical predictions.There are three key points to understanding the resulting circulation in gulf type ROFIs. First, there are likely to be three distinct water masses: the river plume, a brackish upper layer, and a higher salinity lower layer. Second, baroclinic processes in gulf type ROFIs are influenced by the Earth's rotation at first order. Residual currents are quasi-geostrophic and potential vorticity is approximately conserved. Third, the combined effects of a classical longitudinal estuarine circulation and the Earth's rotation are both necessary to produce the resulting circulation. Anti-cyclonic vorticity is generated in the upper layer by the horizontal divergence associated with upward entrainment, which is part of the estuarine circulation. The interaction between anti-cyclonic vorticity and horizontal divergence results in two regions of qualitatively different circulation, with gyre-like circulation near the bay head and uniformly seaward anti-cyclonicly sheared flow further towards the mouth. The stagnation point separating the two regions is closer to (further away from) the bay head for stronger (weaker) horizontal divergence, respectively. The vorticity and spin-up time of this circulation are-(ƒ−ω1)/2 and h/2w0, respectively, where ƒ is the Coriolis parameter, ω1 is the vorticity of the lower layer, h is the depth of the upper layer and w0 is the upward entrainment velocity across the pycnocline. Under high discharge conditions the axis of the river plume proceeds in a right bounded direction, describing an inertial circle clearly seen in satellite images. Under low discharge conditions the river plume is deflected in a left bounded direction by the anti-cyclonic circulation of the upper layer.
All data in the Integrated Marine Information System (IMIS) is subject to the VLIZ privacy policy Top | Authors 
[Back]

WoRMS

Using WoRMS

Tools

Connect with us

This service is powered by LifeWatch Belgium
Learn more»
Website and databases developed and hosted by Flanders Marine Institute · Page generated on 2025-06-17 00:18:53+02:00 · Privacy and cookie policy