Open AccessShallow water currents during Hurricane Andrew
Author(s) -
Keen Timothy R.,
Glenn Scott M.
Publication year - 1999
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/1999jc900180
Subject(s) - downwelling , barotropic fluid , baroclinity , geology , stratification (seeds) , storm , upwelling , oceanography , storm track , climatology , inertial wave , thermocline , atmospheric sciences , wave propagation , physics , seed dormancy , mechanical wave , longitudinal wave , botany , germination , quantum mechanics , dormancy , biology
Oceanographic measurements are used in combination with a numerical model to examine the influence of stratification on shallow water currents during the directly forced stage of a tropical cyclone (Hurricane Andrew) on the continental shelf. The following stratification‐dependent coastal processes are examined: (1) turbulent mixing, (2) coastally trapped waves, (3) near‐inertial oscillations, and (4) upwelling and downwelling. Turbulent mixing was strong within 1 R w (radius of maximum winds) of the storm track, and stratification was nearly destroyed. Turbulent mixing was weak at distances greater than 2 R w . The dominant coastal wave was a barotropic Kelvin wave generated as the storm surge relaxed after landfall. Baroclinic near‐inertial oscillations were dominant at the shelf break and occurred along with a barotropic response on the middle shelf. Downwelling‐favorable flow developed east of the track prior to the storm peak, and upwelling‐favorable flow evolved west of the track as the eye crossed the shelf. The idealized storm flow was modified by local barotropic and baroclinic pressure gradients on the shelf. Ocean circulation during Hurricane Andrew was hindcast using both stratified and unstratified three‐dimensional numerical models. For areas within 1 R w of the storm track, the unstratified model matched the observed currents better than the stratified model, partly because of errors in the initial stratification. At distances greater than 2 R w the influence of stratification increases, and the unstratified model does not reproduce the observed upwelling‐favorable flow.