Release Notes

Release Notes for tiegcm1.95 ($SVN/tiegcm/tags/tiegcm1.95 in the hao repository) Release date: June 20, 2013 Author: Ben Foster (foster@ucar.edu), for the AIM section at HAO.

Source code for version tiegcm1.95 is available at the TGCM download web page: http://www.hao.ucar.edu/modeling/tgcm/download.php

Note that data files for tiegcm1.94 (available as tiegcm1.94_data.tar.gz from the download page) will work with tiegcm1.95.

Performance Examples

• The one-year climatology benchmark, using 16 MPI tasks on Yellowstone averaged 0.10 secs/step, or 1.2 minutes per simulated day with a 2-minute timestep. The run finished 365 days in 7.3 hours wallclock.
• On an hao linux desktop (Optiplex 980), using 4 MPI tasks, the model averaged 0.30 secs/step, or 3.6 minutes per simulated day. Faster times can be expected on newer desktop machines.

Summary of modifications made to the source code since tiegcm1.94.2 (revision r739 on January 6, 2012)

Bug Fixes:

• Repair bug in diags when HMF2,NMF2 are requested, and add conditional to sub hnmf2 to avoid divide by zero when code has been built in debug mode (r759).
• Add max checks to insure that the zpotenm3d geopotential used in sub nosocrdens (current.F) is >= h0 to avoid NaNQ in KQPHI and KQLAM near the magnetic equator (r808).
• Correct buffer length in mp_updateephi, mp_updatelam, mp_updateemz (mpi.F). This was apparently causing a corruption of f4d(n)%data under Linux/intel (r837).
• Fix units bug in eddy and molecular viscosity coefficients in duv.F, resulting in 4-5% change in electron density in E and F regions, up to 4-5% change in zonal wind, negligible changes in meridional wind, and negligible effects on neutral density in the upper thermosphere (~0.5%) (r880).
• Change in the “floor” of the EUVAC solar fluxes from 0.8 times the reference spectrum to 0.1 times the reference spectrum. This makes insignificant difference for F10.7 of 70 or above, but becomes important for “anomalously low” fluxes corresponding to F10.7 in the low 60’s (r928).
• In sub filter2 (filter.F), make part of argument to cos function a real instead of an integer (effects of this change were not quantified) (r945).
• Fixed long-time netcdf error message “string match to name in use”. This error was not fatal, was essentially a warning, but was annoying and confusing (r945).
• More of an improvement than a bugfix: Calculation of time-dependent CO2 concentration used in calculation of implicit and explicit cooling terms in newton.F. This results in 370 ppm in 2000, doubling to 740 ppm in 2100. In previous revisions, CO2 concentration was constant at 350 ppm (r946).

Make/Build System:

• Add logic to job scripts to force gmake clean if debug flag has changed (r796).
• Add logic to job scripts to enable seamless switching between model resolutions (r884,r913).
• Add new job script for the NWSC yellowstone machine, tiegcm-ys.job in the scripts directory. Also add Make.intel_ys and Make.pgi_ys for building on yellowstone, and run.lsf (made by tiegcm-ys.job) for submitting to yellowstone queues (r868).
• Modify scripts/tiegcm-ys.job to allow serial non-mpi runs on the interactive node (r913).

User Interface:

• Add -l option to Linux Intel mpirun command to prefix stdout lines with mpi task ids (r769).
• Add diagnostic FOF2 (r775), and diagnostics BX,BY,BZ,BMAG,EX,EY,EZ,ED1,ED2,PHIM2D (see diags.F) (r945).
• Stop the model with an error message if the number of available mpi tasks is not one of valid_pecounts for which the model has been validated (1,4,8,12,16,24,32,48,64) (r798).
• Update linux job scripts for all benchmark test runs in the tests directory (r945).

Performance and Memory:

• Restrict number of calls to checkf in diags.F, avoiding memory-accumulation problems generated by Intel/ifort implementation of intrinsic function len_trim (r751).
• Remove redundant calls to mk_polelat, mp_bndlats and mp_bndlons from advance.F. Remove unnecessary calls to mp_bndlons_f3d and mp_periodic_f3d at end of dt.F (r759).
• Eliminate sub mp_updatephi (mpi.F), since it is no longer necessary. Changed subs mp_updateemphi, mp_updateemlam and mp_updateemz (mpi.F) to use mpi_bcast rather than mpi_send/recv calls (r826).
• Reduce statically allocated memory in gswm module by dynamically allocating arrays to be read from the data file on subdomains only, rather than globally (r920).

CMIT Coupling:

• Merge modifications of CMIT-coupled tiegcm1.94.2 tag to the trunk (r752)
• Change name of sub getcwd to getcwdir and sub getpid to getprocessid to avoid naming conflicts (r762).

Legacy Rewrite:

• Introduced refactored apex code apex.F90. This is a free-format f90 rewrite of the legacy code apex_subs.F (circa 1995-2000 by Art Richmond, Roy Barnes, et.al.) Old source file apex_subs.F was removed (r931).