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%Verion of gendata.m modified by Vero |
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%This is a matlab script that generates the input data |
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|
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|
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% the configuation approximately the ISOMIP experiment no. 1 |
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% require matlab functions for equation of state |
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|
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|
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% Dimensions of grid |
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nx=1; |
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ny=200; |
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nz=100; |
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delz = 10; |
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|
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hfacMin = 0.2; |
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|
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dlat = 0.125/16; dy=dlat; |
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dlon = 0.125/4; dx=dlon; |
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|
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%eos = 'linear'; |
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eos = 'jmd95z'; |
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% eos = 'mdjwf'; |
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|
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acc = 'real*8'; |
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|
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long = [-105.5:dlon:-105.5]; |
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lonc = long+dlon/2; |
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latg = [-75.4457:dlat:-73.8809-dlat]; |
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latc = latg+dlat/2; |
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size(latc) |
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|
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% Nominal depth of model (meters) |
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H = -1000; %water depth in the ice shelf cavity |
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Hmin = -900; % deepest point of cavern |
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Hmax = -300; % shallowest point of cavern |
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dHdy = (Hmax-Hmin)/(max(latc)-min(latc)); %Slope of ice shelf: if denominator = nx, shelf will cover the whole domain |
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|
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bathy = ones(nx,ny)*H; %For flat bathymetry: bathy = ones(nx,ny)*H; |
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%bathy(1,:) = 0; |
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%bathy(2,:) = 0; |
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%bathy(nx,:) = 0; |
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%bathy(nx-1,:) = 0; |
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bathy(:,1) = 0; |
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%bathy(:,ny) = 0; |
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fid=fopen('bathymetry.pig.bin','w','b'); fwrite(fid,bathy,acc);fclose(fid); |
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|
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|
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dz = delz*ones(1,nz); |
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zgp1 = [0,cumsum(dz)]; |
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zc = .5*(zgp1(1:end-1)+zgp1(2:end)); |
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zg = zgp1(1:end-1); |
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dz = diff(zgp1); |
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sprintf('delZ = %d * %7.6g,',nz,dz) |
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|
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|
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T_sfc = -1.9; |
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T_bottom = 2; |
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del_T = (T_bottom - T_sfc)/(59*delz); |
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|
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for iz = 1:nz; |
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|
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|
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tref(iz) = T_sfc + del_T*((iz-30)*delz); |
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if iz<=30; |
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tref(iz)=-1.9; |
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end |
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if iz>=90 |
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tref(iz) =2; |
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end |
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end |
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|
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S_sfc = 34.2; |
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S_bottom = 34.7; |
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del_S = (S_bottom - S_sfc)/(59*delz); |
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|
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for iz = 1:nz; |
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|
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|
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sref(iz) = S_sfc + del_S*((iz-30)*delz); |
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if iz<=30; |
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sref(iz)=34.2; |
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end |
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if iz>=90 |
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sref(iz) =34.7; |
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end |
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end |
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|
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% Gravity |
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gravity=9.81; |
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rhoConst = 1030; |
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% compute potential field underneath ice shelf |
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talpha = 2e-4; |
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sbeta = 7.4e-4; |
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% tref = -1.9*ones(nz,1); |
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t = tref; |
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% sref = 34.4*ones(nz,1); |
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s = sref; |
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gravity = 9.81; |
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k=1; |
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dzm = abs([zg(1)-zc(1) .5*diff(zc)]); |
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dzp = abs([.5*diff(zc) zc(end)-zg(end)]); |
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p = abs(zc)*gravity*rhoConst*1e-4; |
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dp = p; |
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kp = 0; |
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|
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|
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|
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while rms(dp) > 1e-13 |
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phiHydF(k) = 0; |
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p0 = p; |
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kp = kp+1 |
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for k = 1:nz |
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switch eos |
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case 'linear' |
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drho = rhoConst*(1-talpha*(t(k)-tref(k))+sbeta*(s(k)-sref(k)))-rhoConst; |
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case 'jmd95z' |
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drho = densjmd95(s(k),t(k),p(k))-rhoConst; |
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case 'mdjwf' |
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drho = densmdjwf(s(k),t(k),p(k))-rhoConst; |
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otherwise |
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error(sprintf('unknown EOS: %s',eos)) |
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end |
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phiHydC(k) = phiHydF(k) + dzm(k)*gravity*drho/rhoConst; |
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phiHydF(k+1) = phiHydC(k) + dzp(k)*gravity*drho/rhoConst; |
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end |
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switch eos |
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case 'mdjwf' |
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p = (gravity*rhoConst*abs(zc) + phiHydC*rhoConst)/gravity/rhoConst; |
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end |
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dp = p-p0; |
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end |
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|
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|
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%Modify icetopo (shape of ice shelf cavity) |
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|
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%icetopo = ones(ny,1)*min(Hmin + 2*dHdy*(lonc(nx)-long),Hmax); |
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B=min(Hmin + 2*dHdy*(latc(ny)-latg),Hmax); |
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B=fliplr(B); |
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|
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icetopo = ones(nx,1)*B; |
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%icetopo = icetopo'; |
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icetopo(:,101:end)=0; |
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|
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|
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|
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|
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% adjust topo so that no hfac is smaller than hfacMin |
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|
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for ix=1:nx |
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for iy=1:ny |
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k=max(find(abs(zg)<abs(icetopo(ix,iy)))); |
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|
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if(~isempty(k)) |
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|
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|
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hfacTemp = (icetopo(ix,iy) - (-zg(k+1)))/delz; |
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|
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if (hfacTemp < hfacMin) |
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if (hfacTemp < hfacMin/2) |
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hfacTemp = 0; |
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else |
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hfacTemp = hfacMin; |
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end |
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end |
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|
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else |
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|
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hfacTemp = 0; |
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|
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end |
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|
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icetopo(ix,iy) = icetopo(ix,iy) + hfacTemp; |
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|
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end |
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end |
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|
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% phi anomaly (relative to hydrostatic with rho_const) at icetopo |
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|
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phi0surf = zeros(nx,ny); |
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|
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for ix=1:nx |
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for iy=1:ny |
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k=max(find(abs(zg)<abs(icetopo(ix,iy)))); |
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if isempty(k) |
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k=0; |
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end |
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if k>0 |
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|
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dr = -zg(k) - icetopo(ix,iy); |
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|
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if (dr>=delz/2) |
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phi0surf(ix,iy) = phiHydF(k) + (delz-dr) * (phiHydC(k)-phiHydF(k))/(delz/2); |
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else |
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phi0surf(ix,iy) = phiHydC(k) + (delz/2-dr) * (phiHydF(k+1)-phiHydC(k))/(delz/2); |
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end |
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|
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end |
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end |
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end |
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|
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mass = phi0surf / gravity - rhoConst * icetopo; |
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|
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fid = fopen('shelftopo.pig.bin','w','b'); fwrite(fid,icetopo,'real*8'); fclose(fid); |
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fid = fopen('shelficemassinit.bin','w','b'); fwrite(fid,mass,'real*8'); fclose(fid); |
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fid = fopen('pload.pig.jmd95z','w','b'); fwrite(fid,phi0surf,'real*8'); fclose(fid); |
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|
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etainit = zeros(size(phi0surf)); |
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|
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% new topography: icetopo rounded to the nearest k * deltaZ |
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% eta_init set to make difference |
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|
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icetopo2 = icetopo; |
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|
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for ix=1:nx |
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for iy=1:ny |
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k=max(find(abs(zg)<abs(icetopo2(ix,iy)))); |
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if isempty(k) |
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k=0; |
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else |
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|
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dr = 1-(-zg(k) - icetopo2(ix,iy))/delz; |
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if (dr > .5) |
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% bring Ro_surf *up* to closest grid face & make etainit negative |
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% to compensate |
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icetopo2(ix,iy) = -zg(k); |
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etainit(ix,iy) = (dr-1)*delz; |
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else |
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% bring Ro_surf *down* to closest grid face & make etainit pos |
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% to compensate |
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icetopo2(ix,iy) = -zg(k+1); |
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etainit(ix,iy) = (dr)*delz; |
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end |
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|
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end |
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end |
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end |
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|
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fid = fopen('shelftopo.round.bin','w','b'); fwrite(fid,icetopo2,'real*8'); fclose(fid); |
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fid = fopen('etainit.round.bin','w','b'); fwrite(fid,etainit,'real*8'); fclose(fid); |