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Introduction

A single-column model (SCM) can be a valuable tool for diagnosing the performance of a physics suite, from validating that schemes have been integrated into a suite correctly to deep dives into how physical processes are being represented by the approximating code. This SCM has the advantage of working with and being developed alongside the Common Community Physics Package (CCPP), a library of physical parameterizations for atmospheric numerical models (CCPP physics) and the associated framework for connecting potentially any atmospheric model to physics suites constructed from its member parameterizations (CCPP framework). In fact, this SCM serves as perhaps the simplest example for using the CCPP and its framework in an atmospheric model. This version contains all parameterizations of NOAA’s evolved operational GFS v16 suite (implemented in 2021), plus additional developmental schemes. The schemes are grouped in five supported suites described in detail in the CCPP Scientific Documentation (GFS_v16, GFS_v16_RRTMGP, GFS_v17_p8_ugwpv1, HRRR_gf, and WoFS_v0).

This document serves as both the User and Technical Guides for this model. It contains a Quick Start Guide with instructions for obtaining the code, compiling, and running a sample test case; an explanation for what is included in the repository; a brief description of the operation of the model; a description of how cases are set up and run, and finally, an explanation for how the model interfaces with physics through the CCPP infrastructure.

Please refer to the release web page for further documentation and user notes:

Version Notes

The CCPP SCM v7.0.1 contains the following minor changes since v7.0.0.

  • Enhanced UFS case generation tools: Reinstated functionality to support specifying i, j grid indices (from the FV3 native grid) along with a tile number in UFS_case_gen.py to generate single-column cases. Also added the ability to accept a list of i, j indices for batch generation of multiple cases.
  • Use of standardized missing values: Replaced hard coded missing values, -9999.0 and -9999, with the _FillValue or missing value attributes defined in the NetCDF variables.
  • Fix area logic in the SCM: Corrected assignment of the column area from the DEPHY forcing file by removing the dependency on surface forcing LSM. Also allow the column_area in the configuration namelist to override the DEPHY assignment.
  • Enhanced documentation for 1) using the DEPHY converter script, which converts forcing files from the legacy format to the DEPHY v1.0 format, and 2) including expected behavior of the Near-Surface Sea Temperature (NSST) scheme within the SCM.
  • Added support for NOAA’s Ursa platform using spack-stack v1.9.1.

The CCPP SCM v7.0.0 contains the following major and minor changes since v6.0.

Major

  • Ability to generate SCM cases from UFS simulations using either derived forcings or native forcings from the dynamical core.
  • Support for single precision physics within the SCM.

Minor

  • Addition of new physics schemes; RRTMGP radiation and CLM Lake Model, along with updates to existing schemes.
  • CCPP SCM support for the latest operational/research physics configurations used across UFS applications, including the GFS_v17_p8_ugwpv1, GFS_v16_RRTMGP, and HRRR_gf suites.
  • New SCM cases; MOSAiC-AMPS, MOSAiC-SS, COMBLE, and a catolog of cases in the GdR-DEPHY repository that can be run with CCPP SCM.
  • Updated Scientific Documentation, User's Guide, Technical Documentation, and online tutorials.

Limitations

This release bundle has some known limitations:

  • Using the HRRR_gf and WoFS_v0 suites for cases where deep convection is expected to be active will likely produce strange/unreliable results, unless the forcing has been modified to account for the deep convection. This is because forcing for existing cases assumes a horizontal scale for which deep convection is subgrid-scale and is expected to be parameterized. The suites without convection are intended for use with regional UFS simulations with horizontal scale small enough not to need a deep convection parameterization active, and it does not contain a deep convective scheme. Nevertheless, these suites are included with the SCM as-is for research purposes.
  • The provided cases over land points cannot use an LSM at this time due to the lack of initialization data for the LSMs. Therefore, for the provided cases over land points (ARM_SGP_summer_1997_* and LASSO_*, where sfc_type = 1 is set in the case configuration file), prescribed surface fluxes must be used:
    • surface sensible and latent heat fluxes must be provided in the case data file
    • sfc_flux_spec must be set to true in the case configuration file
    • the surface roughness length in cm must be set in the case configuration file
    • the suite defintion file used (physics_suite variable in the case configuration file) must have been modified to use prescribed surface fluxes rather than an LSM.
    • NOTE: If one can develop appropriate initial conditions for the LSMs for the supplied cases over land points, there should be no technical reason why they cannot be used with LSMs, however.
  • Using the SCM over a land point with an LSM is possible through the use of UFS initial conditions (see :numref:`Section %s <UFScasegen>`).
  • There are several capabilities of the developmental code that have not been tested sufficiently to be considered part of the supported release. Those include additional parameterizations and the CCPP Suite Simulator. Users that want to use experimental capabilities should refer to :numref:`Subsection %s <development_code>`.