CICE-Consortium/CICE: CICE Version 6.4.1

CICE6.4.1 updates CICE6.4.0 from August, 2022 and includes Icepack1.3.3.

This release provides several minor upgrades to the recently released C-grid option. It has several bug fixes including in dEdd scheme affecting modal aerosols and the snow grain implementation. It has updated the VP dynamics option to improve robustness and reproducibility. It moved the evp dynamics deformation calculation to the end of the subcycling loop. It adds new features such as the saltflux_option. Testing and scripts have been updated including addition of a new variable spacing rectangular box option.

This version deprecates the zsalinity option. Please contact the CICE Consortium with any concerns regarding deprecated code. We will consider keeping it.

Important NOTES

• The C-grid implementation is available. However validation is ongoing. Some noise is generated in the solution when incremental remapping advection is used with the C-grid. One solution seems to be to use the upwind advection scheme instead which is more diffusive. The Consortium would appreciate any feedback from the community as users test the C-grid in their applications both with respect to results and possible improvements.
• The cicecore/cicedynB directory was renamed to cicecore/cicedyn. A symlink was added to continue to support use of CICE in applications where the source code paths (including cicecore/cicedynB) are hardwired for compilation or other reasons. This symlink will be removed in the near-future. Applications are encouraged to update their scripts and start using cicedyn instead.

Bug fixes

• Update Icepack, with specific updates for dEdd. Fix several bugs including missing g/w0/tau calculation after "aerosol in snow" and computation of modal aerosol taer/waer/gaer which was not multiplying by nilyr and nslyr properly. Refactor computation of g/w0/tau, get rid of use of puny. Change some constants in dEdd to double precision. Update aerosol tables to double precision in CICE. THIS CHANGES ANSWERS for tr_aero and modal aerosols and could change answers for other configurations #760
• Update Icepack with snwgrain fixes. THIS CHANGES ANSWERS for snow grain cases #797
• Broadcast namelist variable default_season at initialization to all MPI tasks. THIS CHANGES ANSWERS for cases where default_season was not set to winter #766
• Update computation of cdn_ocn in dynamics to use value appropriate to U, E, or N cell location THIS CHANGES ANSWERS but preserves climate #771

Enhancements

• Update grid averaging for tmass, aice, uvelT, and vvelT to improve results. THIS CHANGES ANSWERS but preserves climate #762
• Move evp deformation calculation outside of subcycling loop for B grid, deformation now computed at end of subcyling loop, one subcycle later THIS CHANGES ANSWERS but preserves climate #755
• Refactor strocnxT and strocnyT implementation #764
• Refactor evp subcycling loop, move grid_ice check outside subcycling loop #756
• Update dynamics initialization and other dynamics memory allocation #778
• Update VP implementation to give bit-for-bit reproducibility with different decompositions. VP now supports use of user selected global sum algorithm. Several other minor fixes in VP to improve robustness. THIS CHANGES ANSWERS for VP dynamics but preserves climate #774
• Add saltflux options constant and prognostic #799
• Add time-varying wave forcing, add warning for FSD without waves, make FSD tendencies per second #775
• Refactor ice[T,U,N,E]mask variables, add ice_HaloUpdate2DL1 #773
• Add variable spacing rectangular grid box configurations #746
• Update gridbox_verts call to ensure arrays are always initialized #749
• Update debug_blocks output #750
• Fix computation of stress12T, sig1, sig2, sigP for C-grid configuration, purely diagnostic, also fix underlying grid on history file #790 #802
• Update Kinetic Energy diagnostic, averaging U and V to T grid, changes diagnostic output but not model results #784
• Initialize ice_calendar nstreams variable to improve robustness #752
• Initialize l_readCenter for all grid types to improve robustness #758
• Update Icepack #794 #803
• Add ability to set memory requirements for machine batch submissions settings #750
• Refactor computation of machine pe/task/thread values to new file, setup_mach_params.csh #750
• Update subroutine diagnostic_abort to print output for a failing point #750
• Remove history grids not used #762
• Correct FSD history field units #769
• Remove f_bounds dependency on netcdf #797
• Rename cicedynB directory to cicedyn, create a temporary symlink back to cicedynB #790
• Finalize deprecation of 0-layer thermo and cesm ponds #787
• Deprecate zsalinity feature #795
• Add modal aerosol tests #760
• Update test suite scripts and add dyneap and dynpicard tests #790
• Refactor box test options and box tests #772
• Fix OPENACC error in 1d evp implementation #799
• Updated the qc testing #750
• Updates for conformation with f2003 and f2008 #750
• Remove trailing blanks in many files #750
• Update cice.launch.csh script to improve robustness #776
• Update nuopc/cmeps driver, add wave-ice coupling, async IO #782 #785
• Update ECCC machine files #751
• Update MacOSX conda implementation #750
• Update port to Narwhal #776
• Port to Gust #781
• Add checks for source code in Github Actions, don't want tabs in source code #790

Documentation

• Update to version 6.4.1 #803
• Update Pull Request Template #754
• Update Quick Start documentation #765
• Add rectangular grids section to documentation #772
• Update test suite documentation #790
• Update advection schemes documentation #797