TY - JOUR
T1 - Near-surface currents in DeSoto Canyon (1997-99)
T2 - Comparison of current meters, satellite observation, and model simulation
AU - Wang, Dong Ping
AU - Oey, Lei Yauw
AU - Ezer, Tal
AU - Hamilton, Peter
PY - 2003/1
Y1 - 2003/1
N2 - This study evaluates a data-assimilated model simulation of near-surface circulation in DeSoto Canyon (DSC), Gulf of Mexico, with emphasis on analyzing moored current-meter observations and comparing them with satellite data and model results. The study period is for two years from April 1997 to April 1999. The model results are from a high-resolution Gulf of Mexico model forced by analyzed wind and surface heat flux. Two types of data are used to deduce near-surface circulation: moored current meters at 13 locations in the DSC, and satellite sea level anomaly. The moored currents are mapped through multivariate objective analysis to produce surface currents and surface geopotentials, against which satellite- and model-derived sea surface heights and geostrophic currents are compared. Coupled patterns between the observations, model results, and satellite data are obtained using the singular value decomposition (SVD) analysis. There are two dominant modes: a "single-eddy" mode, in which currents are concentrated at the foot of the canyon, and an "eddy-pair" mode, in which one eddy is at the foot of the canyon and the other, a counterrotating eddy, is over the head of canyon. Mode 1 appears to be associated with the mesoscale eddy traveling around the Loop Current crest and trough, and mode 2 is associated with the intrusion of Loop Current crest and trough over the west Florida shelf. The observed and model currents are in good agreement about the means and variances. The model currents also appear to be well constrained by the steep topography. However, the model velocity field contains only the first mode. The satellite-derived velocity field, on the other hand, contains both the first and second modes: though, the satellite field does not adequately resolve the velocity structures over the slope.
AB - This study evaluates a data-assimilated model simulation of near-surface circulation in DeSoto Canyon (DSC), Gulf of Mexico, with emphasis on analyzing moored current-meter observations and comparing them with satellite data and model results. The study period is for two years from April 1997 to April 1999. The model results are from a high-resolution Gulf of Mexico model forced by analyzed wind and surface heat flux. Two types of data are used to deduce near-surface circulation: moored current meters at 13 locations in the DSC, and satellite sea level anomaly. The moored currents are mapped through multivariate objective analysis to produce surface currents and surface geopotentials, against which satellite- and model-derived sea surface heights and geostrophic currents are compared. Coupled patterns between the observations, model results, and satellite data are obtained using the singular value decomposition (SVD) analysis. There are two dominant modes: a "single-eddy" mode, in which currents are concentrated at the foot of the canyon, and an "eddy-pair" mode, in which one eddy is at the foot of the canyon and the other, a counterrotating eddy, is over the head of canyon. Mode 1 appears to be associated with the mesoscale eddy traveling around the Loop Current crest and trough, and mode 2 is associated with the intrusion of Loop Current crest and trough over the west Florida shelf. The observed and model currents are in good agreement about the means and variances. The model currents also appear to be well constrained by the steep topography. However, the model velocity field contains only the first mode. The satellite-derived velocity field, on the other hand, contains both the first and second modes: though, the satellite field does not adequately resolve the velocity structures over the slope.
UR - http://www.scopus.com/inward/record.url?scp=0038536322&partnerID=8YFLogxK
U2 - 10.1175/1520-0485(2003)033<0313:NSCIDC>2.0.CO;2
DO - 10.1175/1520-0485(2003)033<0313:NSCIDC>2.0.CO;2
M3 - 期刊論文
AN - SCOPUS:0038536322
SN - 0022-3670
VL - 33
SP - 313
EP - 326
JO - Journal of Physical Oceanography
JF - Journal of Physical Oceanography
IS - 1
ER -