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.

MPAS Version 7.0

This major release of MPAS introduces significant new features in the MPAS-Atmosphere model as well as minor fixes and clean-up to the software infrastructure.

Atmosphere

Significant new features or changes to MPAS-Atmosphere v7.0 include:

• The capability to perform limited-area simulations on the surface of the sphere.
• An update to the physics schemes in the 'mesoscale_reference' suite to match the scheme versions in the Weather Research and Forecasting (WRF) model v4.0.3; the WSM6 scheme matches WRF v4.1.
• The addition of two new upper absorbing layer formulations.
• An initial relative humidity field that is computed w.r.t. ice for temperatures below freezing, consistent with the computation used for the model output files.
• A fix for the communication of effective radii between the WSM6 and RRTMG schemes when config_microp_re=true.
• The ability to specify an explicit list of model level heights when constructing the vertical coordinate surfaces in the init_atmosphere core.
• A change to the default sources of data for terrain height and land use category to GMTED2010 and MODIS 20-class, respectively.
• Added MODIS-based sources for monthly albedo, monthly vegetation fraction, and maximum snow albedo; these MODIS datasets are now the default.

IMPORTANT NOTE: The updated physics schemes require new look-up tables, in particular, for the Noah land-surface model. 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.

Infrastructure

Changes to the shared MPAS infrastructure include:

• A new build target, llvm, to enable building MPAS with the clang and flang compilers.
• Updates to the xlf build target to support building on Linux/POWER systems with the XL compilers.
• Various minor fixes and clean-up.

MPAS Version 6.3

This minor release addresses two minor issues in MPAS-Atmosphere.

1. The default setting for config_o3climatology was previously 'false',
   which caused the model to use a single seasonal ozone profile everywhere
   in the model domain when the RRTMG radiation schemes was used. The default
   is now 'true', which causes the model to use the same monthly ozone
   climatology for RRTMG as is used by the CAM radiation schemes.

2. Model simulations using a non-integer timestep would result in 'xtime'
   variables in model output files that were incorrect, which caused problems
   when trying to restart the model at the correct time. The xtime variable
   is now correct when the valid time of output files has no fractional
   seconds.

MPAS Version 6.2

This minor release addresses two issues in the MPAS infrastructure with how character strings are read from netCDF files via PIO, and it adds the 'recursive' attribute to the mpas_log_write routine to avoid errors raised by several newer compilers when critical errors are written.

MPAS Version 6.1

This minor release of MPAS corrects some minor issues with the sea-ice biogeochemistry. It fixes the restartability test with BGC, corrects some BGC namelist flags and removes the zero value for a BGC dimension.

MPAS Version 6.0

This major release of MPAS introduces the MPAS-Seaice core, and it includes new
functionality, general improvements, and fixes to the Ocean, Land Ice, and
Atmosphere cores. Also included are various small improvements, optimizations,
and clean-up in the shared software infrastructure. Specific changes to each of
the MPAS components are detailed below.

Framework:

• Introduction of a new module for logging messages during model execution.
  Unless any errors are encountered, MPAS cores now write a single log file,
  named log.<core>.0000.out. In case errors occur, each MPI task will write
  its own error log file named log.<core>.<task ID>.err.
• Performance enhancements to aggregated halo exchanges used in the Ocean,
  Land-ice, and Sea-ice cores.
• Minor enhancements to the MPAS "stream manager", including the ability to
  specify "final_only" for the "input_interval" or "output_interval" of a stream
  to read/write that stream only at the model stop time.
• Various bug-fixes and other clean-up to ensure that the framework can be used
  in coupled-model configurations involving more than one MPAS core.

Atmosphere:

Relative to the v5.0 release, the MPAS v6.0 release represents a minor
increment in capability for the MPAS-Atmosphere core. MPAS-Atmosphere v6.0
includes:

• An increase of the default number of layers from 41 to 55 to match
  the standard experimental set-up used at NCAR.
• The addition of support for the use of GMTED2010 terrain elevation,
  matching the default terrain dataset used in the WRF model.
  • Set config_topo_data = 'GMTED2010' in the namelist.init_atmosphere file
    when interpolating static fields.
• Computation of the GWDO sub-grid-scale orography fields in a way that is more
  consistent with the pre-computed fields used in the WRF model.
• Support for parallel builds of the init_atmosphere and atmosphere cores.
  • Use make -j N ....
• A significant reduction in the size of model initial conditions files.

Land Ice:

The last MPAS release with land ice improvements was v3.0. MPAS v6.0 adds the
following significant features relative to v3.0:

• Adds support for the First-Order velocity solver through the external Albany
  library.
• Adds a thermal solver that can be solved in terms of temperature (verified)
  or enthalpy (experimental).
• Adds subglacial hydrology model.
• Adds a number of calving options including eigencalving.
• Adds an adaptive time stepper.
• Adds analysis members for global and regional statistics.
• Ability to couple with E3SM.
• Adds a number of test cases and model configurations.
• General cleanup and bug fixes.

Ocean:

• Ability to couple with E3SM.
• New in-situ analysis computations.
• Division of tracers into groups to control output, algorithms, and forcing.
• Addition of biogeochemistry tracers and column computations.

Sea Ice:

• First release of MPAS-Seaice.
• MPAS-Seaice solves the sea-ice momentum equation with an
  Elastic-Viscous-Plastic rheology and variational horizontal operators adapted
  for the MPAS mesh.
• Horizontal transport of mass and tracers uses an incremental remapping scheme.
• Column physics and biogeochemistry uses an early version of the Icepack
  library.

MPAS Version 5.3

This minor release of MPAS corrects an issue with the initialization of the water vapor mixing ratio field in MPAS-Atmosphere, and it also adds two other fixes that should not affect model results.

The MPAS-Atmosphere initialization program (init_atmosphere_model) had previously assumed that any relative humidity field provided in an intermediate file was specified with respect to liquid water at or above 273.15 K, and with respect to ice below this temperature. However, intermediate files produced by the WPS's ungrib.exe program have the RH field adjusted so that is with respect to liquid water everywhere. With this release, the init_atmosphere core correctly interprets the RH field in producing the initial water vapor mixing ratio field. Note that, when initializing from a specific humidity (SPECHUMD) rather than RH, there is no change to results.

Besides the above fix, this release includes two other changes that should have no impact on results:

• The "units" and "description" for scalar tendencies have been corrected in the MPAS-Atmosphere Registry.xml file.
• The sign of the edgeNormalVectors field has been corrected for boundary edges that represent positive normal inflow. Although this change addresses a bug in the code, MPAS-Atmosphere does not have boundary edges, and other MPAS cores either employ no-flux or no-slip conditions along lateral boundaries or arrange such that all boundary edges represent positive outgoing normal velocity.

Thanks very much to The Weather Company for identifying the bug in initializing with relative humidity!

MPAS Version 5.2

This minor release of MPAS corrects issues when using the PIO 2.x library versions. With the changes in this release, it should be possible to use the latest PIO release from https://github.com/NCAR/ParallelIO/.

When compiling MPAS with a PIO 2.x library version, the USE_PIO2=true option should be added to the MPAS build command.

The PIO 2.x library versions support integrated performance timing with the GPTL library; however, the MPAS infrastructure does not currently provide calls to initialize this library before it is used in PIO. Therefore, it is recommended to add -DPIO_ENABLE_TIMING=OFF to the options in the cmake command used to build PIO.

The following steps may be used as a rough guide to obtaining and installing the latest PIO code:

git clone [email protected]:NCAR/ParallelIO.git
cd ParallelIO
export PIOSRC=`pwd`
cd ..
mkdir build
cd build
export CC=mpicc
export FC=mpif90
cmake -DNetCDF_C_PATH=$NETCDF -DNetCDF_Fortran_PATH=$NETCDF -DPnetCDF_PATH=$PNETCDF -DCMAKE_INSTALL_PREFIX=/somewhere/writable/pio2 -DPIO_ENABLE_TIMING=OFF $PIOSRC
make
make install

In the above steps, /somewhere/writable/pio2 should be changed to the installation path for PIO, and after successfully installing, the PIO environment variable should be set to this path as well.