Ocean model validation of the NASA scatterometer winds

The suitability of basin-scale, satellite-based scatterometer winds for for cing of numerical ocean models is examined using a reduced gravity, primiti ve equation model of the tropical Pacific Ocean. Three surface forcing fiel ds are validated in a comparison of upper layer thickness (ULT) from the oc ean model with observed sea level data. The forcing fields are the Florida State University observed winds, winds derived from the NASA Scatterometer (NSCAT), and stresses derived directly from NSCAT. The sea level data sets are the World Ocean Circulation Experiment "fast" sea level data set from i sland measurements and sea level anomalies from TOPEX/POSEIDON. Results of this comparison demonstrate that while the three model results are qualitat ively similar, the results are quantitatively better when forcing with the NSCAT derived stresses. This is particularly true in the eastern tropical P acific and in convergent zones where forcing with the NSCAT stresses can le ad to large differences in ULT (> 40 m) compared with results from the othe r two wind products.