A Note on Satellite Altimeter–Derived Wave Height and Wind Speed Measurements in the Gulf of Mexico

Abstract

The reliability of satellite-based significant wave height (SWH) and wind speed (Ws) measurements in the Gulf of Mexico is examined. Measurements derived from the SARAL/AltiKa, Jason-3, and Sentinel-3A altimeters are compared with in situ buoy observations from 10 National Oceanic and Atmospheric Administration (NOAA) buoys. Collocation windows of 40 km (spatially) and ± 15 min for SWH and ± 10 min for Ws (temporally) were used. Overall, results show strong correlations between satellite and buoy data. SARAL/AltiKa frequently exhibited the best overall performance for wave heights while Jason-3 tended to underestimate them, particularly the higher wave heights (> 2 m). Wind speed retrievals from all missions were also highly consistent with buoy data, with Sentinel-3A yielding the lowest scatter and most stable performance. No significant dependence on distance from the coast was observed, although minor improvements in wind speed accuracy occurred for offshore locations. The results confirm the fidelity of recent satellite altimeter data relative to in situ buoy data, with correlation coefficients exceeding 0.89 for SWH and 0.85 for Ws; it is hoped that these high correlations will spur greater use of altimeter measurements for model validation and data assimilation in the Gulf of Mexico.