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COMPARISON OF ALTIMETRY WAVE AND WIND DATA WITH MODEL AND BUOY DATA. Claus Sølvsteen and Carsten Hansen Oceanographic Dept., Royal Danish Administration of Navigation and Hydrography, Overgaden oven Vandet 62B, 1023 Copenhagen K, Denmark. See Poster n.45.
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COMPARISON OF ALTIMETRY WAVE AND WIND DATAWITH MODEL AND BUOY DATA Claus Sølvsteen and Carsten Hansen Oceanographic Dept., Royal Danish Administration of Navigation and Hydrography, Overgaden oven Vandet 62B, 1023 Copenhagen K, Denmark
See Poster n.45 COMPARISON OF ALTIMETRY WAVE AND WIND DATAWITH MODEL AND BUOY DATA Claus Sølvsteen and Carsten Hansen Oceanographic Dept., Royal Danish Administration of Navigation and Hydrography, Overgaden oven Vandet 62B, 1023 Copenhagen K, Denmark
CONCLUSION • It has been demonstrated that as well satellite as buoy observations are in agreement with the WAVEWATCH-III model. • The WW3 model fits equally well to the satellite data in open as well as semiclosed sea areas. • It has been shown that ERS-2 and Topex SWHs are intercomparable and can be merged together into one data set. • The same applies to wind speeds. • It has been demonstrated that a correction of ERS-2 and Topex SWH data using David Cotton’s algorithms will lead to a better agreement with the significant wave heights, HS, as forecasted by the WW3 model. • On the other hand, applying David Cotton’s algorithms to correct the satellite wind speeds would increase the deviation from the Hirlam wind speed forecasts. • Satellite wind speeds reveal a geographically dependent bias in relation to Hirlam wind speeds. The different oceanographical conditions in the four regions mean that the relationship between wind speed and wave height is different in the four regions. The satellite captures some of these differences, but not all. • It is argued that a wind speed algorithm, which takes σo and SWH as input parameters, may obtain worse results than the Modified Chelton-Wentz algorithm (which uses only σo).
REFERENCES 1. Tolman H.L., Wave Watch III – Model description, http://polar.ncep.noaa.gov/waves/wavewatch/wavewatc h.html , 2004 2. Sølvsteen C. and Hansen C., Validation of the operational wave models WAVEWATCH-III and Mike21-OSW against satellite altimetry and coastal buoys, Royal Danish Administration of Navigation and Hydrography, Vol. K3, 2006, ftp://ftp.fomfrv.dk/pub/Publications/Forecast/Validatio n_of_wave_models_1999_2000.pdf