Extended Reconstructed Sea Surface Temperatures, version 3(ERSST.v3), beginning January
1854.

 
ERSST.v3 is an improved extended reconstruction over version 2. Most of the improvements are justified 
by testing with simulated data.  The major differences are caused by the improved low-frequency (LF) 
tuning of ERSST.v3 which reduces the SST anomaly damping before 1930 using the optimized parameters. 

One of the additional changes is that the low frequency 15-year filter uses data centered on the current year. 
If some of data for 15-year period has not yet been observed, it can, of course, not be used. However, with time
these data will become available. Thus, there may be slight modifications of recent ERSST fields with time.
In the ERSST version 3 on this web page we have removed satellite data from ERSST product. 
For more details about the differences between the merged version 2 and 3 please read:
ftp://eclipse.ncdc.noaa.gov/pub/ersstv3b/merged-product-v3.pdf

ERSST.v3 data (1880 to present) are at: 
ftp://eclipse.ncdc.noaa.gov/pub/ersstv3b

Data are available in both ASCII and NetCDF format. The ASCII data are in this directory 
(ftp://eclipse.ncdc.noaa.gov/pub/ersstv3b/ascii)and are described below. 

The NetCDF data are in ftp://eclipse.ncdc.noaa.gov/pub/ersstv3b/netcdf/ 
and described in more detail there.

THE ASCII DESCRIPTION FOLLOWS:

------------------------------------------------ 

All fields were computed on a 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 ascii file names are: 

ersst.v3b.yyy1.yyy2.asc  .........  ERSST SST for years yyy1 to yyy2

ersst.v3b.esd.yyy1.yyy2.asc  ...    error standard deviation, units (degrees C) 
for years yyy1 to yyy2

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

The following sample code reads both of the ERSST.v3 and the sampling error files.


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.v3 data or the
c*  error standard deviation.  Here the SST file for
c*  1990 to 1999 is used as an example (unit 11).
c
      open(11,file='ersst.v3b.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 June 2008