WDNOTES: notes on estimating wave effects on wind measurements. The following set of mfiles can be used to correct the wind speed Ua measured at height za for the effects of the wave boundary layer following the empirical model presented by Large, Morzel, and Crawford (1995), J. Phys. Oceanog., 25, 2959-2971. In particular, an analytic expression was found for the omega function (omegalmc.m) shown in their Fig. 9b, which allows the 'true' wind speed (Ut10) and stress at 10m (assumed above the wave boundary layer height) to be computed using wavedist.m and the true wind speed (Uta) at the measurement height za using wavedis1.m. The Large et al model assumes neutral stability (reasonable for high winds and wave conditions) and uses a 10-m neutral drag law (cdnve.m) based on Vera (1983; unpublished manuscript). This drag law follows Large and Pond (1982) for winds above 10 m/s but increases at lower wind speeds like Smith (1987). The wave field is specified by the significant wave height Hw. To compute 'true' wind speed Uta at za given Hw, use Uta=wavedis1(Ua,za,Hw). To compute 'true' wind speed Ut at 10m given Hw, use [Ut10,(Ut10-U10)]=wavedist(Ua,za,Hw). To plot the predicted effects of wave distortion on the wind Ua measured at the height za for a range of significant wave heights Hw=[0:2:8] in m, use y=wavedis2(za). Subroutines called: y=omegalmc(x) cd10=cdnve(u10)

0001 % WDNOTES: notes on estimating wave effects on wind measurements. 0002 % The following set of mfiles can be used to correct the wind speed 0003 % Ua measured at height za for the effects of the wave boundary layer 0004 % following the empirical model presented by Large, Morzel, and 0005 % Crawford (1995), J. Phys. Oceanog., 25, 2959-2971. In particular, 0006 % an analytic expression was found for the omega function (omegalmc.m) 0007 % shown in their Fig. 9b, which allows the 'true' wind speed (Ut10) 0008 % and stress at 10m (assumed above the wave boundary layer height) 0009 % to be computed using wavedist.m and the true wind speed (Uta) at the 0010 % measurement height za using wavedis1.m. The Large et al model assumes 0011 % neutral stability (reasonable for high winds and wave conditions) 0012 % and uses a 10-m neutral drag law (cdnve.m) based on Vera (1983; 0013 % unpublished manuscript). This drag law follows Large and Pond (1982) 0014 % for winds above 10 m/s but increases at lower wind speeds like 0015 % Smith (1987). The wave field is specified by the significant wave 0016 % height Hw. 0017 % 0018 % To compute 'true' wind speed Uta at za given Hw, use 0019 % Uta=wavedis1(Ua,za,Hw). 0020 % 0021 % To compute 'true' wind speed Ut at 10m given Hw, use 0022 % [Ut10,(Ut10-U10)]=wavedist(Ua,za,Hw). 0023 % 0024 % To plot the predicted effects of wave distortion on the wind Ua 0025 % measured at the height za for a range of significant wave heights 0026 % Hw=[0:2:8] in m, use 0027 % y=wavedis2(za). 0028 % 0029 % Subroutines called: 0030 % y=omegalmc(x) 0031 % cd10=cdnve(u10) 0032 0033 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0034 % 7/28/99: version 1.1 0035 % 8/5/99: version 2.0 0036 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0037

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