Extended Reconstructed Sea Surface Temperatures, version 2 (ERSST.v2), beginning January
1854.

ERSST.v2 is an improved extended reconstruction of SST.  In both version 1 and version 2 
the high-frequency SST anomalies are reconstructed by fitting to a set of spatial modes.  
In version 1 anomaly increments are reconstructed using anomaly increment modes.  In 
version 2 anomalies are reconstructed using anomaly modes.  In regions where variance is 
relatively large the two are comparable, but version 2 better analyzes the anomalies in 
regions where the variance is low.  In addition, version 2 also uses sea-ice concentrations
to improve the high-latitude SST analysis, and a modified historical bias correction for 
the 1939-1941 period. Version 2 also includes an improved error estimate.


Data are available in this directory. All fields were computed on the 2-degree grid. The 
grid has 180 zonal points and 89 meridional points. The 2-degree cells are centered on 
0E, 2E, ...,and 88S,86S .... Over land a value of -99.99 is assigned.  In addition any 
SST mean value less than -1.8C was set to -1.8C.


The files names are:

ersst.v2.yyy1.yyy2.asc  .........  ERSST SST for years yyy1 to yyy2

ersst.v2.serrv.yyy1.yyy2.asc  ...  estimate of sampling error variance for the analysis, 
for years yyy1 to yyy2

ascii.txt  ................  this file.

The following sample code reads both of the ERSST.v2 and the sampling error files.


c
c   program ersstf.f
c     
c   To read the extended reconstructed SST.
c
      parameter (im=180,jm=89)
c
c   i is longitude index (values 1 to im)
c   j is the latitude index (values 1 to jm)
c
      integer isst(im,jm)
c
c   isst is the input SST array (values are degrees C times 100)
c   land value = -9999
      real ersst(im,jm)
c
c   ersst is the reconstructed SST mean in degrees C
c
   81 format (90i6)
c
c   Open the file to read, either ERSST.v2 data or the
c*  sampling error variance.  Here the SST file for
c*  1990 to 1999 is used as an example (unit 11).
c
      open(11,file='ersst.v2.1990.1999.asc')

      do iy=1990,1999
       do mon=1,12
        do i=1,im
         read(11,81) (isst(i,j),j=1,jm)
        end do
        do 5 j=1,jm
        do 5 i=1,im
         ersst(i,j)=real(isst(i,j))/100.
    5   continue

          ...

       end do
      end do


      stop 
      end



Thomas M. Smith         (e-mail: Tom.Smith@noaa.gov) 
National Climate Data Center
4115 Computer and Space Sciences Building
University of Maryland
College Park, MD  20742-2465  USA


Richard W. Reynolds     (e-mail: Richard.W.Reynolds@noaa.gov)
National Climate Data Center
151 Patton Ave., Room 514,
Asheville, NC  28801

UPDATED: 18 July 2006