%Verion of gendata.m modified by Vero
%This is a matlab script that generates the input data


% the configuation approximately the ISOMIP experiment no. 1
% require matlab functions for equation of state


% Dimensions of grid
nx=3; 
ny=400;
nz=210;
delz = 10;

hfacMin = 0.2;

dlat = 0.125/32; dy=dlat;
dlon = 0.125/4; dx=dlon;

%eos = 'linear';
eos = 'jmd95z';
% eos = 'mdjwf';

acc = 'real*8';

long = [-105.5:dlon:-105.5];
lonc = long+dlon/2;
latg = [-75.4457:dlat:-73.8809-dlat];
latc = latg+dlat/2;
size(latc)

% Nominal depth of model (meters)
H = -1000;					%water depth in the ice shelf cavity
Hmin = -900; % deepest point of cavern		
Hmax = -300; % shallowest point of cavern
dHdy = (Hmax-Hmin)/(max(latc)-min(latc));				%Slope of ice shelf: if denominator = nx, shelf will cover the whole domain

%bathy = ones(nx,ny)*H;				%For flat bathymetry: bathy = ones(nx,ny)*H;
%bathy(1,:) = 0;
%bathy(2,:) = 0;
%bathy(nx,:) = 0; 
%bathy(nx-1,:) = 0; 
%bathy(:,1) = 0;
%bathy(:,ny) = 0;

fid = fopen('bathysteep.box','r','b');
bathy = fread(fid,inf,'real*8');
fclose(fid);
bathy=reshape(bathy, [nx ny]);
fid=fopen('bathy.pig.bin','w','b'); fwrite(fid,bathy,acc);fclose(fid);


dz = delz*ones(1,nz);
zgp1 = [0,cumsum(dz)];
zc = .5*(zgp1(1:end-1)+zgp1(2:end));
zg = zgp1(1:end-1);
dz = diff(zgp1);
sprintf('delZ = %d * %7.6g,',nz,dz)


T_sfc = -1.9;
T_bottom = 2;
del_T = (T_bottom - T_sfc)/(59*delz);

for iz = 1:nz;
    
    
    tref(iz) = T_sfc + del_T*((iz-30)*delz); 
    if iz<=30;
        tref(iz)=-1.9;
    end
    if iz>=90
        tref(iz) =2;
    end
end

S_sfc = 34.2;
S_bottom = 34.7;
del_S = (S_bottom - S_sfc)/(59*delz);

for iz = 1:nz;
    
    
    sref(iz) = S_sfc + del_S*((iz-30)*delz); 
    if iz<=30;
        sref(iz)=34.2;
    end
    if iz>=90
        sref(iz) =34.7;
    end
end

% Gravity
gravity=9.81;
rhoConst = 1030;
% compute potential field underneath ice shelf
talpha = 2e-4;
sbeta  = 7.4e-4;
% tref = -1.9*ones(nz,1);
t    = tref;
% sref = 34.4*ones(nz,1);
s    = sref;
gravity = 9.81;
k=1;
dzm = abs([zg(1)-zc(1) .5*diff(zc)]);
dzp = abs([.5*diff(zc) zc(end)-zg(end)]);
p = abs(zc)*gravity*rhoConst*1e-4;
dp = p;
kp = 0;



while rms(dp) > 1e-13
  phiHydF(k) = 0;
  p0 = p;
  kp = kp+1;
  for k = 1:nz
    switch eos
     case 'linear'
      drho = rhoConst*(1-talpha*(t(k)-tref(k))+sbeta*(s(k)-sref(k)))-rhoConst;
     case 'jmd95z'
      drho = densjmd95(s(k),t(k),p(k))-rhoConst;
     case 'mdjwf'
      drho = densmdjwf(s(k),t(k),p(k))-rhoConst;
     otherwise
      error(sprintf('unknown EOS: %s',eos))
    end
    phiHydC(k)   = phiHydF(k) + dzm(k)*gravity*drho/rhoConst;
    phiHydF(k+1) = phiHydC(k) + dzp(k)*gravity*drho/rhoConst;
  end
  switch eos
   case 'mdjwf'
    p = (gravity*rhoConst*abs(zc) + phiHydC*rhoConst)/gravity/rhoConst;
  end
  dp = p-p0;
end


%Modify icetopo (shape of ice shelf cavity)

%icetopo = ones(ny,1)*min(Hmin + 2*dHdy*(lonc(nx)-long),Hmax); 
B=min(Hmin + 2*dHdy*(latc(ny)-latg),Hmax);
B=fliplr(B);

icetopo = ones(nx,1)*B; 
%icetopo = icetopo';
icetopo(:,101:end)=0;

% use streamice generated thickness
 fid = fopen('hinitsteep3.box','r','b'); hinit=fread(fid,[3 400],'real*8'); fclose(fid);
%hinit(:,1:5)=550;
% load hinit
%hinit(:,1)=1740;
icetopo = -917/1028*hinit;

      for i =1:3
       for j=1:400
     if icetopo(i,j)<bathy(i,j)
        icetopo(i,j)=bathy(i,j)+3;

    end 
end
      end

            for i =1:3
       for j=1:400
     if icetopo(i,j)-bathy(i,j)<3;
        icetopo(i,j)=bathy(i,j)+3;

    end 
end
end
% adjust topo so that no hfac is smaller than hfacMin

%  for ix=1:nx
%    for iy=1:ny
%      k=max(find(abs(zg)<abs(icetopo(ix,iy))));
%  %    
%      if(~isempty(k))
%  %
%  %
%      hfacTemp = (icetopo(ix,iy) - (-zg(k+1)))/delz;
%  %    
%      if (hfacTemp < hfacMin)
%          if (hfacTemp < hfacMin/2)
%              hfacTemp = 0;
%          else
%              hfacTemp = hfacMin;
%          end
%      end
%      
%      else
%          
%          hfacTemp = 0;
%          
%      end
%      
%      icetopo(ix,iy) = icetopo(ix,iy) + hfacTemp;
%      
%    end
%  end
      for i =1:3
       for j=1:400
     if icetopo(i,j)<bathy(i,j)
%        icetopo(i,j)=bathy(i,j)+6;

    end 
end
      end

                  for i =1:3
       for j=1:400
     if icetopo(i,j)-bathy(i,j)<10
%        icetopo(i,j)=bathy(i,j)+delz;

    end 
end
end
% phi anomaly (relative to hydrostatic with rho_const) at icetopo

phi0surf = zeros(nx,ny);

for ix=1:nx
  for iy=1:ny
    k=max(find(abs(zg)<abs(icetopo(ix,iy))));
    if isempty(k)
      k=0;
    end
    if k>0
      
      dr = -zg(k) - icetopo(ix,iy);
      
      if (dr>=delz/2)
          phi0surf(ix,iy) = phiHydF(k) + (delz-dr) * (phiHydC(k)-phiHydF(k))/(delz/2);
      else
          phi0surf(ix,iy) = phiHydC(k) + (delz/2-dr) * (phiHydF(k+1)-phiHydC(k))/(delz/2);
      end
      
    end
  end
end

mass = phi0surf / gravity - rhoConst * icetopo;

%use streamicegenerated thickness

%mass = hinit * 917;
%icetopo(:,1)=-1000;
fid = fopen('shelftopo.pig.bin','w','b'); fwrite(fid,icetopo,'real*8'); fclose(fid);
fid = fopen('shelficemassinit.bin','w','b'); fwrite(fid,mass,'real*8'); fclose(fid);
fid = fopen('pload.pig.jmd95z','w','b'); fwrite(fid,phi0surf,'real*8'); fclose(fid);

etainit = zeros(size(phi0surf));

% new topography: icetopo rounded to the nearest k * deltaZ
%                 eta_init set to make difference

icetopo2 = icetopo;

for ix=1:nx
  for iy=1:ny
    k=max(find(abs(zg)<abs(icetopo2(ix,iy))));
    if isempty(k)
      k=0;
    else
      
      dr = 1-(-zg(k) - icetopo2(ix,iy))/delz;
      if (dr > .25)
          % bring Ro_surf *up* to closest grid face & make etainit negative
          % to compensate
          icetopo2(ix,iy) = -zg(k);
          etainit(ix,iy) = (dr-1)*delz;
      else
          % bring Ro_surf *down* to closest grid face & make etainit pos
          % to compensate
          icetopo2(ix,iy) = -zg(k+1);
          etainit(ix,iy) = (dr)*delz;
      end
       
    end
  end
end

etainit(:,1)=0;
 icetopo2(:,1)=-2100;
fid = fopen('shelftopo.round.bin','w','b'); fwrite(fid,icetopo2,'real*8'); fclose(fid);
fid = fopen('etainit.round.bin','w','b'); fwrite(fid,etainit,'real*8'); fclose(fid);