Wave Measurement Intercomparison and Platform Evaluation during the ITOP (2010) Experiment

Spectral wave parameters from 11 platforms, measured during the recent Impact of Typhoons on the Ocean in the Pacific (ITOP) experiment, are intercompared. Two moorings, separated by similar to 180 km, were deployed in a section of "typhoon alley" off the coast of Taiwan for 4 months. Each mooring consisted of an Air-Sea Interaction Spar (ASIS) buoy that was tethered to a moored Extreme Air-Sea Interaction (EASI) buoy. EAST, the design of which is based on the hull of a 6-m Navy Oceanographic Meteorological Automatic Device (NOMAD) buoy, is validated as a 1D wave sensor against the established ASIS. Also, during this time three drifting miniature wave buoys, a wave-measuring marine radar on the Research Vessel Roger Revelle, and several overpasses of Jason-1 (C and Ku bands) and Jason-2 (Ku band) satellite altimeters were within 100 km of either the northern or southern mooring site. These additional measurements were compared against both EASI buoys. Findings are in-line with previous wave parameter intercomparisons. A corroborated measurement of mean wave direction and direction at the peak of the spectrum from the EASI buoy is presented. Consequently, this study is the first published account of directional wave information that has been successfully gathered from a buoy with a 6-m NOMAD-type hull. This result may be applied to improve operational coverage of wave direction. A high level of confidence is established in the ITOP wave data. Advantages and disadvantages of the different sensor types are discussed, which may be useful for the design of future field experiments.