This is the twenty-third ECMWF-users' newsletter.  To get copies of previous
newsletters, use anonymous FTP to ncardata.ucar.edu [128.117.8.111] and
change directory to datasets/ds111.2/news.  Or, use a WWW browser and open 
http://www.ucar.edu/dss/datasets/ds111.2.html and select "news".

			27 June 1996

CONTENTS:

	o Change in data format beginning March 1996;  new software required
	o ECMWF Documents at NCAR now have tables of contents online

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	Change in data format

ECMWF has begun to use an extended Product Definition Section (PDS) in
their GRIB files.  This change begins with the March 1996 data for the
Basic Consolidated Dataset (ds111.2);  it will probably be present in
the 1996 data from the advanced datasets, when we get them.  This change
was made because the extended PDS is used in the ECMWF reanalysis data,
and they are trying to maintain internal consistency.

These changes have the following implications:

1) Beginning with the March 1996 data, the record length is increased
from 10560 to 10680 bytes.

2) You must increase the length of several arrays in your main program.
If you call GRIBEX with this calling sequence:

	call gribex (ksec0, ksec1, ksec2, psec2, ksec3, psec3, 
     &               ksec4, f, jpflen, igrib, jpglen, idum, hoper, ierr)

then the following arrays must be redimensioned:

	ksec1(60)	[increased from 25]
	ksec2(384)	[increased from 23]
	psec2(96)	[increased from 10]

The main programs access.qsub (for the NCAR Crays) and access.f (for 
other computers) on ncardata.ucar.edu in the /datasets/ds111.2/software/
directory (and the directories for the other ECMWF datasets as well)
have been updated this way.

3) If you are using the data on your own system, you must retrieve a new 
version of the decoding subroutines.  These are also located in the
/datasets/ds111.2/software/ directory (and the directories for the other 
ECMWF datasets as well).  You will need a new copy of gribsubs.f as
well as a new copy of the appropriate machine-specific code (either
subs_cray.f, subs_sun.f, or subs_vax.f).

If you are using the data on the NCAR Crays, the MSS files containing
the decoding subroutines (/DSS/P/ACC/GRIB/SUBS and /DSS/P/ACC/GRIB/CRAY)
have been updated, so no action is required.  However, if you fail to
increase the length of the arrays as described in (2), your program
will not work!

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	ECMWF Documents at NCAR

For some time we have made copies of ECMWF Research Manual 3 available.
This manual covers the physical parameterization used in the model.
We have recently received Research Manual 1, which describes the 
data assimilation, and Research Manual 2, which describes the adiabatic
part of the forecast model.  

The tables of contents of these documents are now available online
on the ncardata.ucar.edu machine, in a directory called model_docs in
each of the ECMWF dataset directories.  You can reach them directly
at ftp://ncardata.ucar.edu/datasets/ds111.2/model_docs.  

Please email me at ilana@ncar.ucar.edu if you need portions of any of 
these manuals.  Include your mailing address and your fax number.

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If you would like to be taken off this mailing list, please contact me.
If you are interested in ordering any ECMWF/TOGA data, or any other data
from NCAR's archives, please contact me.  I can be reached at
ilana@ncar.ucar.edu or by phone at (303)497-1214.

Ilana Stern
Data Support Section
National Center for Atmospheric Research