Data Preparation for 1-Degree Resolution Global Ocean Synthesis

The contents of this page decribe the procedures to prepare initialization, forcing and constrained data for the 1-degree global synthesis by the ECCO Consortium.
The procedures described at MIT Model--Data Preprocessing shall not be repeated here. This page complements Report No. 18 in the ECCO project report series.

Topography

Calculating the median of the 2-minute resolution topography data of Sandwell et al within each 1deg by 1 deg grid box.The data file downloaded is topo_8.2.img. The Matlab routine to compute the median is gen_1x1.m in /net/fjord2/youyu/data2model/sandwell/. In each model grid box, the median is computed for negative topography values (water depth) if more than 50% of the data values falling in that box are negative. Otherwise this grid box is treated as land.

x=0.5:1:359.5;
y=-79.5:1:79.5;
dx=1; dy=1;

Hmedian1=zeros(length(x),length(y))*nan;
Hmean1=zeros(length(x),length(y))*nan;

for j=1:160;
disp(j)
if y(j)>=-71.5 & y(j) <=71.5
for i=1:360;
lonw=x(i)-dx/2;
if lonw==0; lonw=lonw+0.04;end
lone=x(i)+dx/2;
lats=y(j)-dy/2;
latn=y(j)+dy/2;
clear He2 xe 2 ye2

[He2,xe2,ye2] = mygrid_sand([lats latn lonw lone]);
dum=He2(:);
J=find(dum<0);
if length(J)>length(dum)*0.5;
Hmedian1(i,j)=median(dum(J));
Hmean1(i,j)=mean(dum(J));
end;end;end;end

save H1x1.mat Hmean1 Hmedian1

Outside of the coverage areas of the Sandwell et al data ( -72.006 to 72.006 N), the median of the ETOPO5 data is caculated and merged with the median of the Sandwell et al data.
The resulting 1-deg data are manually edited with the guide of coastline data. Special attention is paid to critical areaes such as the Straits of Florida and the Indonesian Seas.
Output files:

bathymetry.bin	bathymetry [x,y]
pmask.bin	mask at pressure grids [x,y,z]

Climatology of hydrography

Two variables: potential temperature and salinity. Derived from Levitus et al (1994), see MIT Model-- Data Preprocessing.
Outfiles:

lev_clim_temp.bin	annual mean potential temperature [x,y,z]	deg C
lev_clim_salt.bin	annual mean salinity [x,y,z]	psu
lev_monthly_sstemp.bin	monthly sea surface temperature at Levitus z=0 [x,y,t]	deg C
lev_monthly_sssalt.bin	monthly sea surface salinity at Levitus z=0 [x,y,t]	psu
lev_monthly_temp.bin	monthly sst, volume interpolated to first model level [x,y,t]	deg C
lev_monthly_salt.bin	monthly sss, volume interpolated to first model level [x,y,t]	psu

lev_monthly_temp_new.bin	monthly potential temperature [x,y,z,t]	deg C
lev_monthly_salt_new.bin	monhtly salinity [x,y,z,t]	psu

Surface Forcing

From NCEP/NCAR reanalysis:

NCEP_R_ustr_92-01_1x1	twice daily zonal wind stress [x,y,t]	??
NCEP_R_vstr_92-01_1x1	twicedaily meridional wind stress [x,y,t]	??
NCEP_R_sw_92-01_1x1	daily	??
NCEP_R_emp_92-01_1x1	daily	??
NCEP_R_turbflux_92-01_1x1	daily	??

Sea surface height (SSH)

Topex/Poseidon and ERS data

TP_daily_92-01_1x1	[x,y,t]	m
TP_mean_s	[x,y]	m
ERS_daily_1x1_92-01	[x,y,t]	m

River runoff

run-off.bin_1x1 mean river runoff [x,y] m/yr

Hydrography sections

The data from hydrography sections are downloaded from the csv files at the WHP website http://whpo.ucsd.edu/whp_data.htm .

- convert temperature to potential temperature,
- convert 2db pressure intervals to depth,
- interpolate and output potential temperature and salinity on 10m depth levels

Data during 1992-1999 are binned to model grid s in each month of each year using /net/fjord2/youyu/data2model/WOCE_CTD/cre_CTD1x1.m

dz=[10.,10.,15.,20.,20.,25.,35.,50.,75.,100.,150.,200.,275.,350.,...
415.,450.,500.,500.,500.,500.,500.,500.];
% 415.,450.,500.,500.,500.,500.,500.,500.,500.];
zmodel=[ 0 cumsum(dz)];
%nx=180;ny=80;nz=23;
nx=360;ny=160;nz=23;

%load /net/fjord2/dspiegel/MODEL2WOCE9yr/reformatted/ptem_ctd_reformatted
load /net/fjord2/dspiegel/MODEL2WOCE9yr/reformatted/sal_ctd_reformatted

%ctd=ptem_ctd_reformatted;
ctd=sal_ctd_reformatted;

for yt=1992:1999

% fidout=fopen(['ctdT'num2str(yt)],'wb');
fidout=fopen(['ctdS'num2str(yt)],'wb');
tmpint=-9999.99*ones(360,160,23,12);

clear ctd1
I=find(ctd(:,6)==yt);
ctd1=ctd(I,:);

for m=1:12
    indt=find(ctd1(:,7)==m);
    xt=ctd1(indt,3);
    yt=ctd1(indt,4);
    zt=ctd1(indt,5);
    mapt=ctd1(indt,10);

xk=floor(xt/1)+1;
yk=floor((yt+80)/1)+1;

    while length(xk)>0
      indij=find(xk==xk(1) & yk==yk(1));
      zij=zt(indij);
      mapij=mapt(indij);
      for k=2:23;
        indijk=find(zij<zmodel(k) & zij>zmodel(k-1));
        if length(indijk)>0
             tmpint(xk(1),yk(1),k-1,m)=mean(mapij(indijk));
        end
      end
      xk(indij)=[];
      yk(indij)=[];
      zt(indij)=[];
      mapt(indij)=[];
    end

end

fwrite(fidout,tmpint,'float32')
fclose(fidout)
end % year loop

Data from pre -1992 cruises are grided to a "climatology" file of monthly data, i.e., the data are grouped according to month without using the "year" information.

% pre-1992 data:

% fidout=fopen('ctdT_pre1992','wb');
fidout=fopen('ctdS_pre1992','wb');
tmpint=-9999.99*ones(360,160,23,12);

clear ctd1
I=find(ctd(:,6)<1992);
ctd1=ctd(I,:);

for m=1:12
    disp(m)
    indt=find(ctd1(:,7)==m);
    xt=ctd1(indt,3);
    yt=ctd1(indt,4);
    zt=ctd1(indt,5);
    mapt=ctd1(indt,10);

xk=floor(xt/1)+1;
yk=floor((yt+80)/1)+1;

end

fwrite(fidout,tmpint,'float32')
fclose(fidout)

Files generated:

ctdT_1x1_92_01	10-year monthly potential temperature [x,y,z,t]	deg C
ctdS_1x1_92_01	10-year monthly salinity [x,y,z,t]	psu
ctdT_1x1_pre1992	monthly "climatology" of potential temperature [x,y,z,t]	deg C
ctdT_1x1_pre1992	monthly "climatology" of salinity [x,y,z,t]	psu

XBT

Data collected during 1992-2001 are binned to model grids in each month of each year using /net/fjord2/youyu/data2model/XBT/cre_monthlyXBT_1x1.m

%00-01:
year=2001;
load gxbt.y01

%98-99:
year=1999;
load axbt.y99
load pxbt.y99
load ixbt.y99
gxbt=[axbt;pxbt;ixbt];

%92:
year=1992;
load /net/fjord2/cking/MODEL2XBT/axbt.y92.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/pxbt.y92.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/G_ixbt.y92.model2xbt_iter103_CA_combined

%93:
year=1993;
load /net/fjord2/cking/MODEL2XBT/axbt.y93.model2xbt_iter103_CA_combined.tmp
load /net/fjord2/cking/MODEL2XBT/pxbt.y93.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/G_ixbt.y93.model2xbt_iter103_CA_combined

%94:
year=1994;
load /net/fjord2/cking/MODEL2XBT/axbt.y94.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/pxbt.y94.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/G_ixbt.y94.model2xbt_iter103_CA_combined

%95:
year=1995;
load /net/fjord2/cking/MODEL2XBT/axbt.y95.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/pxbt.y95.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/G_ixbt.y95.model2xbt_iter103_CA_combined

%96:
year=1996;
load /net/fjord2/cking/MODEL2XBT/axbt.y96.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/pxbt.y96.model2xbt_iter103_CA_combined.tmp
load /net/fjord2/cking/MODEL2XBT/G_ixbt.y96.model2xbt_iter103_CA_combined

%97:
year=1997;
load /net/fjord2/cking/MODEL2XBT/axbt.y97.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/pxbt.y97.model2xbt_iter103_CA_combined
load /net/fjord2/cking/MODEL2XBT/G_ixbt.y97.model2xbt_iter103_CA_combined

gxbt=[axbt;pxbt;G_ixbt];

xp=gxbt(:,3);
yp=gxbt(:,4);
zp=gxbt(:,5);
tp=gxbt(:,6);
Tp=gxbt(:,7);

mX=floor(tp/(3600*24*30.4375)-(year-1992)*12.0)+1;
xp1=xp;yp1=yp;zp1=zp;tp1=mX;Tp1=Tp;

fidout=fopen(['XBT_1x1',num2str(year)],'wb');
xbt=ones(nx,ny,nz,12)*(-9999.99);

for m=1:12
    m
    indt=find(tp1==m);
    xp2=xp1(indt);yp2=yp1(indt);zp2=zp1(indt);Tp2=Tp1(indt);

xk=floor(xp2/1)+1;
yk=floor((yp2+80)/1)+1;

    while length(xk)>0
      indij=find(xk==xk(1) & yk==yk(1));
      zij=zp2(indij);
      Tij=Tp2(indij);
      for k=2:23;
        indijk=find(zij<zmodel(k) & zij>zmodel(k-1));
        if length(indijk)>0
             xbt(xk(1),yk(1),k-1,m)=mean(Tij(indijk));
        end
      end
      xk(indij)=[];yk(indij)=[];zp2(indij)=[];Tp2(indij)=[];
    end
end

fwrite(fidout,xbt,'float32')
fclose(fidout)

Some temperature data from ARGO floats are contained in the XBT data. In principle the following piece of Matlab script can be inserted into the above script before bining to 1x1 grids. However it is very time consuming so the ARGO data have not been separated from the XBT data yet.

% floats data

cd /net/fjord2/youyu/data2model/floats_new/data

load ag_glob_99_01.dat
load rd_indc_94_01.dat
load rd_corc_97_01.dat
load rd_satl_94_01.dat
load rd_natl_94_00.dat
load ri_natl_97_01.dat

glbT=[ag_glob_99_01;rd_indc_94_01;rd_corc_97_01;rd_satl_94_01;rd_natl_94_00;ri_natl_97_01];

xF=glbT(:,2);
yF=glbT(:,3);
zF=glbT(:,4);
ddate=glbT(:,5);
mapTT=glbT(:,6);
mapSS=glbT(:,7);
mapTT(find(mapTT<-9))=nan;
mapSS(find(mapSS<-9))=nan;

cd /net/fjord2/youyu/data2model/XBT

% Compress the floats data (only keep one level in a profile)

mF=floor(ddate/(3600*24*30.4375)-(year-1992)*12.0)+1;
I=find(mF>0 & mF <13 & isnan(mapTT)==0);
xF1=xF(I);yF1=yF(I);zF1=zF(I);tF1=mF(I);TF1=mapTT(I);

xF2=[];yF2=[];zF2=[];tF2=[];TF2=[];

while length(xF1)>50;
length(xF1)
xF2=[xF2;xF1(1)];yF2=[yF2;yF1(1)];zF2=[zF2;zF1(1)];tF2=[tF2;tF1(1)];TF2=[TF2;TF1(1)];
xF1(1)=[];yF1(1)=[];zF1(1)=[];tF1(1)=[];TF1(1)=[];
I=find(xF1(1:50)==xF1(1) & yF1(1:50)==yF1(1) & tF1(1:50)==tF1(1));
if length(I)>0;
I(1)=[];
xF1(I)=[];yF1(I)=[];zF1(I)=[];tF1(I)=[];TF1(I)=[];
end;end

while length(xF1)>0;
length(xF1)
xF2=[xF2;xF1(1)];yF2=[yF2;yF1(1)];zF2=[zF2;zF1(1)];tF2=[tF2;tF1(1)];TF2=[TF2;TF1(1)];
xF1(1)=[];yF1(1)=[];zF1(1)=[];tF1(1)=[];TF1(1)=[];
I=find(xF1==xF1(1) & yF1==yF1(1) & tF1==tF1(1));
if length(I)>0;
I(1)=[];
xF1(I)=[];yF1(I)=[];zF1(I)=[];tF1(I)=[];TF1(I)=[];
end;end

% Remove the repeated floats data from XBT data

mX=floor(tp/(3600*24*30.4375)-(year-1992)*12.0)+1;
xp1=xp;yp1=yp;zp1=zp;tp1=mX;Tp1=Tp;

for k=1:length(TF2);
k
I=find(xp==xF2(k) & yp==yF2(k) & zp==zF2(k) & mX==tF2(k));
if length(I)>0
xp1(I)=[];yp1(I)=[];zp1(I)=[];tp1(I)=[];Tp1(I)=[];
end;end

Data files generated

XBT_1x1_92_01

10-year monthly potential temperature [x,y,z,t]

deg C

Floats

Data during 1995-2001 are binned to model grids in each month of each year using /net/fjord2/youyu/data2model/floats_new/data/cre_monthlyARGO_1x1.m

%---------------------------------------

load ag_glob_99_01.dat
load rd_indc_94_01.dat
load rd_corc_97_01.dat
load rd_satl_94_01.dat
load rd_natl_94_00.dat
load ri_natl_97_01.dat

glbT=[ag_glob_99_01;rd_indc_94_01;rd_corc_97_01;rd_satl_94_01;rd_natl_94_00;ri_natl_97_01];

x=glbT(:,2);
y=glbT(:,3);
z=glbT(:,4);
ddate=glbT(:,5);
mapTT=glbT(:,6);
mapSS=glbT(:,7);
mapTT(find(mapTT<-9))=nan;
mapSS(find(mapSS<-9))=nan;

for year=1992:2001;
fidtout=fopen(['ARGO_T_',num2str(year),'_1x1'],'wb');
fidsout=fopen(['ARGO_S_',num2str(year),'_1x1'],'wb');
flT=ones(nx,ny,nz,12)*(-9999.99);
flS=ones(nx,ny,nz,12)*(-9999.99);

     month=floor(ddate/(3600*24*30.4375)-(year-1992)*12.0)+1;
       for m=1:12
        m
        indt=find(month==m);
        mapt=mapTT(indt);
        maps=mapSS(indt);
        xt=x(indt); I=find(xt<0);xt(I)=xt(I)+360;
        yt=y(indt);
        zt=z(indt);

        for k=2:18
          indk=find(zt<zmodel(k) & zt>zmodel(k-1));
          maptk=mapt(indk);
          mapsk=maps(indk);
          xk=xt(indk);
          yk=yt(indk);
          for i=1:nx
             for j=1:ny
               indij=find(xk>(i-1)*1.0&xk<i*1.0 &...
                  yk>(j-1)*1.0-80.0&yk<j*1.0-80.0);
               if length(indij)>0
                 flT(i,j,k-1,m)=mean(maptk(indij));
                 flS(i,j,k-1,m)=mean(mapsk(indij));
      end;end;end;end;end;

% clear map date x y z ij k

   fwrite(fidtout,flT,'float32')
   fwrite(fidsout,flS,'float32')
   fclose(fidtout)
   fclose(fidsout)
end

Data files generated:

ArgoT_1x1_92_01	10-year monthly potential temperature [x,y,z,t]	deg C
ArgoS_1x1_92_01	10-year monthly salinity [x,y,z,t]	psu

Drifter velocity

Time-mean near-surface velocities are derived from the trajectories of surface drifers (at nominal depth 15 m). The velocity data represent averages over 6 deg in longitude and 2 deg in latitude boxes. The velocities are positioned from 3E to 357 E (spaced by 6 deg) in lonitude and from 79S to 79N (spaced by 2 deg) in latitude. On 1-deg grids the velocities are treated as uniform in each 6x2 box.
Files created

udrifter_1x1	[x,y]	cm/s
vdrifter_1x1	[x,y]	cm/s
udrifterror.err	[x,y]	cm/s
vdrifterror.err	[x,y]	cm/s

Youyu Lu, 6/25/2002