WAVES IN THE GREAT PACIFIC GARBAGE PATCH: CROSS VALIDATION OF THREE MEASUREMENT TECHNIQUES AND TWO WW3 MODELS

摘要

The Ocean Cleanup Foundation is developing floating barrier systems to concentrate and extract buoyant plastic from the global accumulation zones. To analyze and improve the efficiency of such cleanup systems, access to accurate Metocean conditions is inevitable. The Ocean Cleanup runs its own implementation of WAVEWATCH Ⅲ~R to have full control over the spatiotemporal resolution and to have access to all critical output, such as 2D wave spectra or Stokes drift at the surface to only name two examples. We present here an experimental campaign that was carried out during the deployment of the first two systems in the Pacific to A) validate the performance of both a GFS and CFSR forced wave model, 1000+nm from available NOAA buoys and B) intercompare the wave measurements from an unmanned surface vessel (USV) with those from wave buoys and a vessel based X-Band radar. The USV is the most feasible tool to collect long periods of data along the system trajectory and our preferred option in the long run. We zoom into one day to review in detail the various data sources, their comparability and employed post processing techniques. We present a preliminary comparison of integral wave parameters for the entire campaign (2272hrs/data points) and discuss further steps towards a more complete investigation. The preliminary comparison suggests that the USV and wave buoy data compare rather well. The largest differences are seen in wave periods. We observe small differences between the GFS and CFSR forced model, both compare well with the field measurements.