CDNLP: computes neutral drag coefficient following Large&Pond (1981). [cd,u10]=CDNLP(sp,z) computes the neutral drag coefficient and wind speed at 10m given the wind speed at height z following Large and Pond (1981), J. Phys. Oceanog., 11, 324-336. INPUT: sp - wind speed [m/s] z - measurement height [m] OUTPUT: cd - neutral drag coefficient at 10m u10 - wind speed at 10m [m/s]

- as_consts AS_CONSTS: returns values of many constants used in AIR_SEA TOOLBOX

- spshftlp SPSHFTTC: adjusts wind speed from z1 to z2 following Large&Pond (1981).
- stresslp STRESSLP: computes neutral wind stress following Large and Pond (1981).

0001 function [cd,u10]=cdnlp(sp,z) 0002 % CDNLP: computes neutral drag coefficient following Large&Pond (1981). 0003 % [cd,u10]=CDNLP(sp,z) computes the neutral drag coefficient and wind 0004 % speed at 10m given the wind speed at height z following Large and 0005 % Pond (1981), J. Phys. Oceanog., 11, 324-336. 0006 % 0007 % INPUT: sp - wind speed [m/s] 0008 % z - measurement height [m] 0009 % 0010 % OUTPUT: cd - neutral drag coefficient at 10m 0011 % u10 - wind speed at 10m [m/s] 0012 0013 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0014 % 3/8/97: version 1.0 0015 % 8/26/98: version 1.1 (vectorized by RP) 0016 % 8/5/99: version 2.0 0017 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% 0018 0019 as_consts; % define physical constants 0020 a=log(z./10)/kappa; % log-layer correction factor 0021 tol=.001; % tolerance for iteration [m/s] 0022 0023 u10o=zeros(size(sp)); 0024 cd=1.15e-3*ones(size(sp)); 0025 u10=sp./(1+a.*sqrt(cd)); 0026 0027 ii=abs(u10-u10o)>tol; 0028 while any(ii(:)), 0029 u10o=u10; 0030 cd=(4.9e-4+6.5e-5*u10o); % compute cd(u10) 0031 cd(u10o<10.15385)=1.15e-3; 0032 u10=sp./(1+a.*sqrt(cd)); % next iteration 0033 ii=abs(u10-u10o)>tol; % keep going until iteration converges 0034 end;

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