Peer-Reviewed Journal Details
Mandatory Fields
O'Donncha, F,Hartnett, M,Nash, S,Ren, L,Ragnoli, E
2015
February
Journal Of Marine Systems
Characterizing observed circulation patterns within a bay using HF radar and numerical model simulations
Published
WOS: 30 ()
Optional Fields
Numerical modelling Radar Harmonic analysis Baroclinic OCEAN SURFACE CURRENTS WIND-DRIVEN CURRENTS CONTINENTAL-SHELF ADCP MEASUREMENTS COASTAL OCEAN SEA BIGHT FLOW TEMPERATURE VARIABILITY
142
96
110
In this study, High Frequency Radar (HFR), observations in conjunction with numerical model simulations investigate surface flow dynamics in a tidally-active, wind-driven bay; Galway Bay situated on the West coast of Ireland. Comparisons against ADCP sensor data permit an independent assessment of HFR and model performance, respectively. Results show root-mean-square (rms) differences in the range 10 - 12cm/s while model rms equalled 12 - 14cm/s. Subsequent analysis focus on a detailed comparison of HER and model output. Harmonic analysis decompose both sets of surface currents based on distinct flow process, enabling a correlation analysis between the resultant output and dominant forcing parameters. Comparisons of barotropic model simulations and HFR tidal signal demonstrate consistently high agreement particularly of the dominant M2 tidal signal. Analysis of residual flows demonstrate considerably poorer agreement, with the model failing to replicate complex flows. A number of hypotheses explaining this discrepancy are discussed, namely: discrepancies between regional-scale, coastal-ocean models and globally-influenced bay-scale dynamics; model uncertainties arising from highly-variable wind-driven flows across alarge body of water forced by point measurements of wind vectors; and the high dependence of model simulations on empirical wind-stress coefficients. The research demonstrates that an advanced, widely-used hydro-environmental model does not accurately reproduce aspects of surface flow processes, particularly with regards wind forcing. Considering the significance of surface boundary conditions in both coastal and open ocean dynamics, the viability of using a systematic analysis of results to improve model predictions is discussed. (C) 2014 Elsevier B.V. All rights reserved.
10.1016/j.jmarsys.2014.10.004
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