MPAS Version 8.2.2

This bugfix release addresses several issues in the MPAS-Atmosphere model
and in the MPAS infrastructure. Specific changes include:

• Fix to a portability issue in the MPAS registry 'parse' tool, which caused
  files in the src/core_<CORE>/inc directory to not be generated correctly at
  build time on some systems (PR #1229).

• Addition of two fields, brtemp and cldmask, that are needed by MPAS-JEDI.
  Although not needed by stand-alone MPAS-Atmosphere, these fields are
  associated with the jedi_da package and therefore have no effect when
  MPAS-Atmosphere is run without setting config_jedi_da = true (PR #1232).

• Removal of a redundant query of the nCellsSolve dimension in the
  physics_run_init routine. The extra query had no impact on results, and its
  removal can be considered clean-up (PR #1236).

Acknowledgements: Thanks to Ted Mansell (NOAA NSSL) and Michael Toy (NOAA GSL)
for identifying issues that have been addressed in this release.

MPAS Version 8.2.1

This bugfix release addresses several issues in the MPAS-Atmosphere model
and in the MPAS infrastructure. Notable changes include:

• Improved detection of an 'mpi_f08' module (PR #1202), as well as improved
  detection of netCDF and PnetCDF library paths (PR #1203), in the top-level
  Makefile.

• The addition of a missing dependency in the physics Makefile to correct
  parallel build issues (PR #1204).

• Fixes to the CMake build files used by MPAS-JEDI (PR #1205).

• Fixes to double-precision builds of MPAS-Atmosphere (PR #1207, PR #1208).

• Correction of the calculation of height AGL used in the computation of 1-km
  radar reflectivity fields (PR #1213).

• Correction of an issue that prevented the MYNN PBL scheme from being used
  without also using the Thompson aerosol-aware microphysics (PR #1215).

• Fixes to allow MPAS-Atmosphere to be built without physics (i.e., dynamics-
  only builds) (PR #1221).

• Various code cleanup and minor corrections (PR #1206, PR #1212, PR #1224,
  PR #1226).

Acknowledgements: Thanks to Michael Toy (NOAA GSL) for first identifying the error
in the calculation of the height AGL array that affect the 1 km radar reflectivity fields.

MPAS Version 8.2.0

This release of MPAS introduces several significant changes to MPAS-Atmosphere.

New physics

• The Noah-MP v5.0.1 land-surface model is now available by setting
  config_lsm_scheme = 'sf_noahmp' in the &physics namelist group.

  • New static files that include the soilcomp, soilcl1, soilcl2,
    soilcl3, and soilcl4 fields are required when activating Noah-MP in
    the model.

• The aerosol-aware Thompson microphysics (as in WRF v4.1.4) is available by
  setting config_microp_scheme = 'mp_thompson_aerosols' in the &physics
  namelist group.

  • An aerosol climatology file (QNWFA_QNIFA_SIGMA_MONTHLY.dat) is used when
    running the init_atmosphere_model program to produce initial and lateral
    boundary conditions for nifa and nwfa.

Physics changes

• Physics schemes in the physics_mmm directory are now obtained from a
  separate, shared MMM-physics repository at compile time using the
  manage_externals tool.

• The revised Monin-Obukhov scheme replaces the Monin-Obukhov scheme in the
  'mesoscale_reference' suite.

GPU capabilities

• The scalar transport code has been ported to GPUs using OpenACC directives.

  • The atmosphere core must be compiled with OPENACC=true.
  • Additional timers in the log file capture host-device data transfer times.

Infrastructure

• The build system no longer requires an intermediate clean step when compiling
  one core before another.

MPAS Version 8.1.0

This release of MPAS introduces several updates and new capabilities for MPAS-Atmosphere, most notably:

• The MYNN Surface Layer and Planetary Boundary Layer (PBL) schemes have been updated. The PBL scheme includes the options needed to run the Eddy Diffusivity Mass Flux (EDMF) scheme.

• A separate driver for the parameterization of surface processes over sea-ice points has been added.

• The build system now tests for the availability of the modern mpi_f08 module in the MPI library. If detected, the mpi_f08 module interface to Fortran MPI routines will be used in favor of the older mpi module interface.

• The atmosphere core now supports the storage and retrieval of time-invariant fields in a separate I/O stream, offering significant disk space savings, especially in cases where large ensembles or cycled simulations are being run. See Section 8.3 of the User's Guide for more details.

• The top-level Makefile provides a new intel build target for the Intel oneAPI Fortran, C, and C++ compiler suite.

• To support real-data simulations on meshes with grid distances approaching 1 km or less, the init_atmosphere core provides an option, config_30s_supersample_factor, for super-sampling of the 30 arc-second terrestrial fields (terrain, land use, soil category, and MODIS FPAR monthly vegetation fraction).

• When compiling, PRECISION=single is now the default, and double-precision builds must be specified with PRECISION=double.

MPAS Version 8.0.2

This bugfix release addresses several issues in the MPAS-Atmosphere model:

• Generalize the mpas_sphere_angle function to provide correct results for non-unit-radius spheres. This generalization fixes problems in remapping static fields to the outermost layer of specified-zone cells in limited-area meshes. (PR #1148)

• Initialize mvd_r and mvd_c before first use in the Thompson microphysics scheme to prevent the potential use of uninitialized memory, which could lead to floating-point exceptions. (PR #1152)

• Correct the units for the grid scale input field to the Thompson cloud fraction scheme. (PR #1153)

Acknowledgements: Thanks are due to Brett Wilt (The Weather Company) for first identifying the bug in the units of dx_p in the call to the Thompson cloud fraction scheme.

MPAS Version 8.0.1

This bugfix release addresses several issues in MPAS-Atmosphere, specifically:

• Fix an OpenMP error in the deallocation of an array (rthdynten) when neither
  the Grell-Freitas nor the Tiedtke/nTiedtke cumulus schemes are used. (PR #1099)

• Fix a compilation issue due to a missing include path for the physics_mmm
  directory when certain Fortran compilers are used. (PR #1096)

• Fix an issue in reading real-valued global attributes from input files with
  SMIOL when the input file is of a different precision than the compiled
  precision of MPAS. (PR #1091)

• Fix a memory leak for the recloud_p, reice_p, and resnow_p arrays in the
  deallocate_microphysics routine. (PR #1090)

• Correct the units and description for the rt_diabatic_tend, pv_vertex,
  pv_edge, and pv_cell variables in the atmosphere core's Registry.xml file. (PRs #1089 and #1092)

MPAS Version 8.0.0

This major release of MPAS introduces significant new features in the
MPAS-Atmosphere model and its supporting software infrastructure.

Initialization:

• Enable parallel remapping of static fields with arbitrary graph partition
  files; special CVT partition files are no longer required.

• Reset the default for the lower air-temperature extrapolation
  (config_extrap_airtemp) from 'linear' to 'lapse-rate' in the namelist. This
  applies to initialization and to lateral boundary condition generation for
  MPAS-A.

• Set the condition for the lower extrapolation of the horizontal velocity
  such that it returns the lowest analysis level value instead of a linear
  extrapolation when the requested level is below the analysis level.

• Create a new init case (13) for creating 3-d CAM-MPAS grids.

Physics:

• Update the Noah land surface scheme to the WRF 4.5 release.

• Update the MM5 surface layer scheme to the WRF 4.5 release.

• Implemented the CCPP-compliant version of:

  • the revised MM5 surface layer scheme;
  • the parameterization of the gravity-wave drag over orography;
  • the YSU Planetary Boundary Layer scheme;
  • the scale-aware nTiedtke parameterization of convection; and
  • the WSM6 cloud microphysics parameterization.

• Correct the initialization of the maximum snow albedo over sea ice points
  (now set to 0.75 instead of 0).

• Fix the option that defines the surface albedo over sea ice points. The
  default option is now set to zero and the default value for the surface
  albedo over sea ice points is set to 0.65.

• In the dynamics, rework the computation of the advective tendency of
  potential temperature needed as forcing in the nTiedtke and Grell-Freitas
  parameterizations of deep convection. The advective tendency of potential
  temperature is now computed the same way for the nTiedtke and Grell-Freitas
  convection schemes.

  IMPORTANT NOTE: The updated Noah scheme requires new look-up tables.
  The checkout_data_files.sh script that is run at build time should correctly
  update these tables, but tables in other run directories will need to be
  manually updated.

Dynamics:

• Modify the regional MPAS-A relaxation-zone filters to increase the
  robustness of regional MPAS-A simulations, including access to specific
  relaxation-zone filter parameters through the namelist. The defaults for
  regional relaxation-zone filtering for the horizontal momentum have been
  changed from the previous release.

• Generalize the 2nd-order horizontal mixing used in the upper wave absorbing
  region in MPAS-A, including access to the configuration parameters through
  the namelist.

• The pressure-level height diagnostic is now interpolated using ln(p) for
  increased accuracy. This significantly reduces the diagnostics height bias
  in the previous version.

• Change the vertical interpolation weights for projecting cell-centered
  variables to w levels to be the vertically integrated average. Previously
  the weights represented a linear interpolation in z. These weights are
  computed in the initialization code and used in both the initialization and
  integration.

• Eliminate the need to specify a horizontal length scale in namelists
  (config_len_disp). New mesh files supply this length scale, which is read by
  the model at start-up.

• Include changes to the initialization and to MPAS-A such that this release
  can be directly used in CESM/CAM.

Infrastructure:

• Introduce a new I/O layer, the Simple MPAS I/O Layer. SMIOL provides a
  subset of the parallel I/O functionality of PIO, but with a simplified
  design that minimizes external dependencies to just the Parallel-NetCDF
  library. When the $PIO environment variable is not set at compile time,
  SMIOL will be used in MPAS.

• Refactor halo communication to make use of a new group (aggregated) halo
  exchange module. The new mpas_halo module is designed to be amenable to
  GPU-direct communication of halos with OpenACC. In this release, however,
  OpenACC directives have not yet been added.

MPAS Version 7.3

This minor release addresses one issue in the MPAS-Atmosphere model.

MPAS-Atmosphere:

• Update the checkout_data_files.sh script to use HTTPS rather than the
  unencrypted Git protocol when obtaining the MPAS-Data repository from
  GitHub.

MPAS Version 7.2

This minor release addresses several issues in the MPAS-Atmosphere model.

MPAS-Atmosphere:

• Correct the use of uninitialized memory in the init_atm_case_squall_line
  routine by initializing the qvb array to zero before its first use.

• Fix a bug in the vertical extrapolation of relative humidity and specific
  humidity to model levels below the lowest first-guess level when first-guess
  levels are given in top-to-bottom order in the input intermediate file.

• Fix reproducibility issues in several fields within the Noah LSM over land-ice
  points when running with different MPI task counts; however, only one of these
  fields -- smstav, the surface moisture availability field -- persists outside
  of the physics driver and is written to MPAS-Atmosphere restart files.

• Correct the units and description attributes for the GWDO fields var2d, con,
  oa1, oa2, oa3, oa4, ol1, ol2, ol3, and ol4 in both the init_atmosphere and
  atmosphere core Registry.xml files.

• Add code that had inadvertently been omitted for computing dtheta_dt_mp, the
  potential temperature heating rate from microphysics. Prior to this change,
  the dtheta_dt_mp field would always contain a constant zero value when written
  to model output files.

• Correct a check on the availability of the dtheta_dt_mix variable when
  computing depv_dt_mix in the PV diagnostics module.

• Correct the parallel computation of iLev_DT (and other fields that depend on
  it, including u_pv, v_pv, theta_pv, vort_pv, depv_dt_diab_pv, and
  depv_dt_fric_pv) in the PV diagnostics module.

MPAS Version 7.1

This minor release addresses several issues in the MPAS-Atmosphere model and
initialization, and it corrects several minor compilation issues.

MPAS-Atmosphere:

• In calculating moist air density in the real-data initialization case, virtual
  temperature, rather than temperature, should be used.

• An out-of-bounds array access in the GWDO scheme when running with multiple
  OpenMP threads has been corrected.

• A check has been added in the init_atmosphere core to ensure that the
  intermediate file interval and the 'surface' stream output interval are
  consistent.

• A non-standard BOZ-literal constant has been corrected in the
  module_ra_cam_support.F file. The non-standard constant lead to build
  failures, particularly with newer versions of the GNU compilers.

General software:

• The logic to add PIO libraries to the definition of LIBS in the top-level
  Makefile has been updated to accommodate newer versions (approx. 2.5.2 or
  later) of the PIO library; without the fix to the Makefile, builds would
  fail with the message

  Checking for a usable PIO library...
  ************ ERROR ************
  Failed to compile a PIO test program
  Please ensure the PIO environment variable is set to the PIO installation directory
  ************ ERROR ************

• Various options for the 'gfortran' build target have been cleaned up.

• Occasional parallel build failures related to a race condition in the ezxml
  library compilation have been addressed.