From: ccm@sage.cgd.ucar.EDU (CCM Group Directories)
Message-Id: <199405132040.OAA19609@grub.cgd.ucar.edu>
Subject: New ftp distribution
To: ccm-users@ncar.UCAR.EDU
Date: Fri, 13 May 94 14:40:14 MDT
*** New CCM2 ftp distribution package available ***
A new CCM2 ftp distribution package is now available via anonymous
ftp from ftp.ucar.edu. Instructions for transferring the CCM2 package
are included later in this message. The contents of the distribution
package are functionally identical to the earlier distribution. The
package has been updated to reflect recent compiler and operating system
changes on the NCAR Cray Y-MP/8 and the NCAR IBM RS-6000 platforms, and
to address what now appears to be misleading information associated
with the R15 component included in the earlier distributions.
Recent mail traffic on the ccm-users mail group suggests that users
may be running the CCM2 with an R15 truncation using the job scripts
included with the ftp distribution. As we attempted to point out in
the earlier distributions, the CCM2 was developed and validated at a
T42 horizontal resolution, which remains the recommended resolution at
which to integrate the model. The R15 datasets and job scripts were
included only for the purpose of providing a computationally
inexpensive configuration for installing the CCM2 on external computer
systems, and for quickly testing code changes of a development nature.
Nevertheless, we now realize that a certain segment of the user
community will insist on using the R15 configuration in their research
activities. We also realize that the information contained in earlier
distributions may have confused, and in the process misled, users
about the suitability of the R15 job scripts for production use of the
model (e.g., the use of a 30 minute time step, which was chosen to
minimize the cost of 1-day test integrations when installing the
code). Consequently, we have configured the sample R15 job scripts in
the new distribution package as they would be for an R15 production
integration. The changes from the T42 job scripts include the
appropriate coefficient for the bi-harmonic diffusion at R15 (namelist
variable DIF4), the appropriate resolution parameters ("#define PLON 48",
etc.), and a filepath that points to a modified version of cldfrc.F
(i.e., with parameters more suitable to an R15 configuration).
Although the dynamical model is stable using a 30 minute time step, a
20 minute time step is necessary for production work at R15 because of
known instabilities in the physical parameterizations under certain
extreme synoptic conditions. Although this makes a low-resolution
installation process a little more complex and somewhat more
expensive, it avoids confusion over what constitutes a reasonable
model configuration at R15.
The remaining changes are of a technical nature and reflect changes to
computational environments at NCAR (that likely exist elsewhere). The
IBM job decks were changed to reflect a namelist syntax change
(related to Fortran 90) as well as compiler flag changes for implicit
double precision required to accommodate library changes on the NCAR
RS6000 cluster (-qautodbl=dblpad becomes -qrealsize=8 -qintsize=4).
Subroutine SETTAU and the IBM job decks were changed to accommodate
library changes for the requisite LINPACK routines (CALL SGECO, CALL
SGEDI become CALL DGECO, CALL DGEDI respectively; -lblas must be added
to the command which builds the executable). Routine names SGECO and
SGEDI included in the util/ directory were changed to DGECO and DGEDI
accordingly. Finally, the Cray decks were changed to reflect proper
"assign" syntax for SSD access under Unicos 8.0 (assign -F sds.scr
fort.xx becomes assign -F sds.scr u:xx).
***********
INSTRUCTIONS FOR TRANSFERRING THE CCM2 FTP DISTRIBUTION PACKAGE
On your local computer, connected to the internet, type:
ftp ftp.ucar.edu
or
ftp 128.117.64.2
At login prompt, type: anonymous
At password prompt, type: your e-mail address
To get to the CCM2 code, type:
cd ccm
A history of changes made to the standard ftp distribution package is
contained in this directory in the file README.HISTORY. The CCM2.1
package is contained in a tar file of slightly more than 11 MB in
size. To transfer this file to your machine, type:
bin
get ccm2.tar
To terminate your ftp session, type:
quit
On your local system, you may "untar" this file by typing:
tar -xvf ccm2.tar
This operation will result in two files, a documentation file called
"README", and a tar file (ccm2.1.tar) containing all files necessary for
installing and running CCM2.1. The README file explains the terms and
conditions associated with this distribution, and provides a description
of the CCM2.1 package.
As before, anyone who acquires the CCM2 distribution package for
external installation is strongly encouraged to register their name,
mailing address, and e-mail address, by sending mail to
ccm@ncar.ucar.edu. Although most elements of this package have been
rigorously tested, there are components that have not been validated
in terms of long climate integrations (e.g., the R15 version which
includes the distributed BATS land surface model). All registered
users will be notified via e-mail about any known problems or updates
to the distribution package. Additionally, all registered users will
be included on CGD mailings concerning CCM related activities (such as
workshops).
We also remind users that a ccm-users discussion group has been
established as an open e-mail forum for rapid exchange of information,
ideas, and topics of interest relating to the various versions of the
NCAR CCM (Community Climate Model) and the CCM Modular Processor. To
subscribe, send mail to MajorDomo@ncar.ucar.edu with the words
"subscribe ccm-users" as the complete mail text. You will receive
confirmation via e-mail and will automatically receive future postings.