Reconciling Discrepancies Between Airborne and Buoy-Based Measurements of Wind Stress Over Mixed Seas
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In a previous study it was found that airborne and buoy-based measurements of wind stress made in the Gulf of Tehuantepc, México failed to agree. Here we revisit the issue and analyze data from both platforms in the context of flux-sampling strategies and find that there is now good agreement between wind-stress estimates from both experiments. The sampling strategies used for airborne and buoy-based sampling capture most of the contributing scales to the momentum flux and, correspondingly, the systematic errors for both stress estimates are low. On the other hand, the random error is much larger for the airborne measurements as compared with that for the buoy-based estimates. Increasing the averaging period for the aircraft-based estimates reduces the random error and brings the stress estimates into a better agreement with those from the buoy data. Since there is a good agreement between stress estimates, the apparent underestimation found earlier seems to be coincidental and caused by the interpolation method employed by the source paper.
KeywordsAirborne measurements Eddy covariance Sampling errors Wind stress
We thank Margaret A. LeMone and three other anonymous reviewers whose suggestions and comments reshaped and enriched this work. GOTEX data were provided by NCAR/EOL under sponsorship of the National Science Foundation. GOTEX was a collaborative effort of groups from Scripps Institution of Oceanography (UCSD), UC Irvine, NASA/EG&G, NCAR and the Universidad Autónoma de México (UNAM), led by W. Kendall Melville and Carl A. Friehe. The research was partially sponsored by PROMEP (Project UABC-10160), CONACYT (Project 155793, RugDiSMar) and the Office of Naval Research (NRL contribution: NRL/JA/7260-14-0051).
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