.. glossary::
advect
To transport substances in the atmostphere by :term:`advection`.
advection
According to the American Meteorological Society (AMS) `definition <https://glossary.ametsoc.org/wiki/Advection>`__, advection is "The process of transport of an atmospheric property solely by the mass motion (velocity field) of the atmosphere." In common parlance, advection is movement of atmospheric substances that are carried around by the wind.
ATM
The Weather Model configuration that runs only the standalone atmospheric model.
AQM
The `Air Quality Model <https://github.com/NOAA-EMC/AQM>`__ (AQM) is a UFS Application that dynamically couples the Community Multiscale Air Quality (:term:`CMAQ`) model with the UFS Weather Model through the :term:`NUOPC` Layer to simulate temporal and spatial variations of atmospheric compositions (e.g., ozone and aerosol compositions). The CMAQ, treated as a column chemistry model, updates concentrations of chemical species (e.g., ozone and aerosol compositions) at each integration time step. The transport terms (e.g., :term:`advection` and diffusion) of all chemical species are handled by the UFS Weather Model as :term:`tracers<tracer>`.
CCPP
The `Common Community Physics Package <https://dtcenter.org/community-code/common-community-physics-package-ccpp>`__ is a forecast-model agnostic, vetted collection of code containing atmospheric physical parameterizations and suites of parameterizations for use in Numerical Weather Prediction (:term:`NWP`) along with a framework that connects the physics to the host forecast model.
CCPP-Framework
The infrastructure that connects physics schemes with a host model; also refers to a software
repository of the same name
CCPP-Physics
The pool of CCPP-compliant physics schemes; also refers to a software repository of the same name
CDEPS
The `Community Data Models for Earth Predictive Systems <https://github.com/NOAA-EMC/CDEPS/>`__ repository (CDEPS) contains a set of :term:`NUOPC`-compliant data components and :term:`ESMF`-based "stream" code that selectively removes feedback in coupled model systems. In essence, CDEPS handles the static Data Atmosphere (:term:`DATM`) integration with dynamic coupled model components (e.g., :term:`MOM6`). The CDEPS data models perform the basic function of reading external data files, modifying those data, and then sending the data back to the :term:`CMEPS` mediator. The fields sent to the :term:`mediator` are the same as those that would be sent by an active component. This takes advantage of the fact that the mediator and other CMEPS-compliant model components have no fundamental knowledge of whether another component is fully active or just a data component. More information about DATM is available in the `CDEPS Documentation <https://escomp.github.io/CDEPS/html/index.html>`__.
CESM
The `Community Earth System Model <https://www.cesm.ucar.edu/>`__ (CESM) is a fully-coupled global climate model developed at the National Center for Atmospheric Research (:term:`NCAR`) in collaboration with colleagues in the research community.
chgres_cube
The preprocessing software used to create initial and boundary condition files to "coldstart" the forecast model. It is part of :term:`UFS_UTILS`.
CICE
CICE6
Sea Ice Model
`CICE <https://github.com/NOAA-EMC/CICE>`__ is a computationally efficient model for simulating the growth, melting, and movement of polar sea ice. It was designed as one component of a coupled atmosphere-ocean-land-ice global climate model. CICE has several interacting components, including a model of ice dynamics, a transport model that describes :term:`advection` of different state variables; and a vertical physics package called "Icepack".
CMAQ
The `Community Multiscale Air Quality Model <https://www.epa.gov/cmaq/cmaq-models-0>`__ (CMAQ, pronounced "cee-mak") is a numerical air quality model that predicts the concentration of airborne gases and particles and the deposition of these pollutants back to Earth's surface. The purpose of CMAQ is to provide fast, technically sound estimates of ozone, particulates, toxics, and acid deposition. CMAQ is an active open-source development project of the U.S. Environmental Protection Agency (EPA). Code is publicly availably at https://github.com/USEPA/CMAQ.
CMEPS
The `Community Mediator for Earth Prediction Systems <https://github.com/NOAA-EMC/CMEPS>`__ (CMEPS) is a :term:`NUOPC`-compliant :term:`mediator` used for coupling Earth system model components. It is currently being used in NCAR's Community Earth System Model (:term:`CESM`) and NOAA's subseasonal-to-seasonal (S2S) coupled system. More information is available in the `CMEPS Documentation <https://escomp.github.io/CMEPS/versions/master/html/index.html>`__.
cron
cron job
crontab
cron table
Cron is a job scheduler accessed through the command-line on UNIX-like operating systems. It is useful for automating tasks such as regression testing. Cron periodically checks a cron table (aka crontab) to see if any tasks are are ready to execute. If so, it runs them.
data assimilation
Data assimilation is the process of combining observations, model data, and error statistics to achieve the best estimate of the state of a system. One of the major sources of error in weather and climate forecasts is uncertainty related to the initial conditions that are used to generate future predictions. Even the most precise instruments have a small range of unavoidable measurement error, which means that tiny measurement errors (e.g., related to atmospheric conditions and instrument location) can compound over time. These small differences result in very similar forecasts in the short term (i.e., minutes, hours), but they cause widely divergent forecasts in the long term. Errors in weather and climate forecasts can also arise because models are imperfect representations of reality. Data assimilation systems seek to mitigate these problems by combining the most timely observational data with a "first guess" of the atmospheric state (usually a previous forecast) and other sources of data to provide a "best guess" analysis of the atmospheric state to start a weather or climate simulation. When combined with an "ensemble" of model runs (many forecasts with slightly different conditions), data assimilation helps predict a range of possible atmospheric states, giving an overall measure of uncertainty in a given forecast.
DATM
DATM is the *Data Atmosphere* component of :term:`CDEPS`. It uses static atmospheric forcing files (derived from observations or previous atmospheric model runs) instead of output from an active atmospheric model. This reduces the complexity and computational cost associated with coupling to an active atmospheric model. The *Data Atmosphere* component is particularly useful when employing computationally intensive Data Assimilation (DA) techniques to update ocean and/or sea ice fields in a coupled model. In general, use of DATM in place of :term:`ATM` can be appropriate when users are running a coupled model and only want certain components of the model to be active. More information about DATM is available in the `CDEPS Documentation <https://escomp.github.io/CDEPS/versions/master/html/datm.html>`__.
DOCN
DOCN is the *Data Ocean* component of :term:`CDEPS`. It uses static ocean forcing files (derived from observations or previous ocean model runs) instead of output from an active ocean model. This reduces the complexity and computational cost associated with coupling to an active ocean model. The *Data Ocean* component is particularly useful when employing computationally intensive Data Assimilation (DA) techniques to update atmospheric fields in a coupled model. In general, use of DOCN in place of :term:`MOM6` or :term:`HYCOM` can be appropriate when users are running a coupled model and only want certain components of the model to be active. More information about DOCN is available in the `CDEPS Documentation <https://escomp.github.io/CDEPS/versions/master/html/docn.html>`__.
dycore
dynamical core
Global atmospheric model based on fluid dynamics principles, including Euler's equations of motion.
EMC
The `Environmental Modeling Center <https://www.emc.ncep.noaa.gov/emc_new.php>`__ is one of :term:`NCEP`'s nine centers and leads the :term:`National Weather Service <NWS>`'s modeling efforts.
ESMF
`Earth System Modeling Framework <https://earthsystemmodeling.org/docs/release/latest/ESMF_usrdoc/>`__. The ESMF defines itself as "a suite of software tools for developing high-performance, multi-component Earth science modeling applications." It is a community-developed software infrastructure for building and coupling models.
FMS
The Flexible Modeling System (FMS) is a software framework for supporting the efficient
development, construction, execution, and scientific interpretation of atmospheric,
oceanic, and climate system models.
FV3
FV3 dycore
FV3 dynamical core
The Finite-Volume Cubed-Sphere :term:`dynamical core` (dycore). Developed at NOAA's `Geophysical
Fluid Dynamics Laboratory <https://www.gfdl.noaa.gov/>`__ (GFDL), it is a scalable and flexible dycore capable of both hydrostatic and non-hydrostatic atmospheric simulations. It is the dycore used in the UFS Weather Model.
GOCART
NASA's Goddard Chemistry Aerosol Radiation and Transport (GOCART) model simulates the distribution of major tropospheric aerosol types, including sulfate, dust, organic carbon (OC), black carbon (BC), and sea salt aerosols. The UFS Weather Model integrates a prognostic aerosol component using GOCART. The code is publicly available on GitHub at https://github.com/GEOS-ESM/GOCART.
HPC-Stack
The `HPC-Stack <https://github.com/NOAA-EMC/hpc-stack>`__ is a repository that provides a unified, shell script-based build system for building the software stack required for numerical weather prediction (NWP) tools such as the `Unified Forecast System (UFS) <https://ufscommunity.org/>`__ and the `Joint Effort for Data assimilation Integration (JEDI) <https://jointcenterforsatellitedataassimilation-jedi-docs.readthedocs-hosted.com/en/latest/>`__ framework.
HAFS
The Hurricane Analysis and Forecast System (`HAFS <https://github.com/NOAA-EMC/HAFS>`__) is a :term:`UFS` application for hurricane forecasting. It is an :term:`FV3`-based multi-scale model and data assimilation (DA) system capable of providing analyses and forecasts of the inner core structure of tropical cyclones (TC) --- including hurricanes and typhoons --- out to 7 days. This is key to improving size and intensity predictions. HAFS also provides analyses and forecasts of the large-scale environment that is known to influence a TC's motion. HAFS development targets an operational analysis and forecast system for hurricane forecasters with reliable, robust and skillful guidance on TC track and intensity (including rapid intensification), storm size, genesis, storm surge, rainfall, and tornadoes associated with TCs. Currently, HAFS is under active development with collaborative efforts among NCEP/EMC, AOML/HRD, GFDL, ESRL/GSD, ESRL/NESII, OFCM/AOC, and NCAR/DTC.
HYCOM
The HYbrid Coordinate Ocean Model (`HYCOM <https://www.hycom.org/>`__) was developed to address known shortcomings in the vertical coordinate scheme of the Miami Isopycnic-Coordinate Ocean Model (MICOM). HYCOM is a primitive equation, general circulation model with vertical coordinates that remain isopycnic in the open, stratified ocean. However, the isopycnal vertical coordinates smoothly transition to z-coordinates in the weakly stratified upper-ocean mixed layer, to terrain-following sigma coordinates in shallow water regions, and back to z-level coordinates in very shallow water. The latter transition prevents layers from becoming too thin where the water is very shallow. See the `HYCOM User's Guide <https://www.hycom.org/attachments/063_hycom_users_guide.pdf>`__ for more information on using the model. The `HYCOM model code <https://github.com/NOAA-EMC/HYCOM-src>`__ is publicly available on GitHub.
LND
land component
The Noah Multi-Physics (Noah-MP) land surface model (LSM) is an open-source, community-developed LSM that has been incorporated into the UFS Weather Model (WM). It is the UFS WM's land component.
Mediator
A mediator, sometimes called a coupler, is a software component that includes code for representing component interactions. Typical operations include merging data fields, ensuring consistent treatment of coastlines, computing fluxes, and temporal averaging.
MOM
MOM6
Modular Ocean Model
MOM6 is the latest generation of the Modular Ocean Model. It is numerical model code for simulating the ocean general circulation. MOM6 was originally developed by the `Geophysical Fluid Dynamics Laboratory <https://www.gfdl.noaa.gov/mom-ocean-model/>`__. Currently, `MOM6 code <https://github.com/mom-ocean/MOM6>`__ and an `extensive suite of test cases <https://github.com/NOAA-GFDL/MOM6-examples/wiki>`__ are available under an open-development software framework. Although there are many public forks of MOM6, the `NOAA EMC fork <https://github.com/NOAA-EMC/MOM6>`__ is used in the UFS Weather Model.
MRW
MRW App
The `Medium-Range Weather Application <https://github.com/ufs-community/ufs-mrweather-app>`__ is a UFS Application that targets predictions of atmospheric behavior out to about two weeks. It packages a prognostic atmospheric model (the UFS Weather Model), pre- and post-processing tools, and a community workflow.
NCAR
The `National Center for Atmospheric Research <https://ncar.ucar.edu/>`__.
NCEP
National Centers for Environmental Prediction (NCEP) is a branch of the :term:`National Weather Service <NWS>` and consists of nine centers, including the :term:`Environmental Modeling Center <EMC>`. More information can be found at https://www.ncep.noaa.gov.
NCEPLIBS
The software libraries created and maintained by :term:`NCEP` that are required for running
:term:`chgres_cube`, the UFS Weather Model, and the :term:`UPP`. They are included in `spack-stack <https://github.com/NOAA-EMC/spack-stack>`__ and `HPC-Stack <https://github.com/NOAA-EMC/hpc-stack>`__.
NCEPLIBS-external
A collection of third-party libraries required to build :term:`NCEPLIBS`, :term:`chgres_cube`,
the UFS Weather Model, and the :term:`UPP`. They are included in :term:`spack-stack` and :term:`HPC-Stack`.
NEMS
The NOAA Environmental Modeling System is a common modeling framework whose purpose is
to streamline components of operational modeling suites at :term:`NCEP`.
netCDF
NetCDF (`Network Common Data Form <https://www.unidata.ucar.edu/software/netcdf/>`__) is a file format and community standard for storing multidimensional scientific data. It includes a set of software libraries and machine-independent data formats that support the creation, access, and sharing of array-oriented scientific data.
NG-GODAS
Next Generation-Global Ocean Data Assimilation System. NG-GODAS is a UFS Weather Model configuration that couples ocean (:term:`MOM6`), sea ice (:term:`CICE6`), and Data Assimilation (DA) capabilities with the :term:`DATM` component of :term:`CDEPS`.
NUOPC
National Unified Operational Prediction Capability
The `National Unified Operational Prediction Capability <https://earthsystemmodeling.org/nuopc/>`__ is a consortium of Navy, NOAA, and Air Force modelers and their research partners. It aims to advance the weather modeling systems used by meteorologists, mission planners, and decision makers. NUOPC partners are working toward a common model architecture --- a standard way of building models --- in order to make it easier to collaboratively build modeling systems.
NUOPC Layer
The :term:`NUOPC` Layer "defines conventions and a set of generic components for building coupled models using the Earth System Modeling Framework (:term:`ESMF`)."
NUOPC applications are built on four generic components: driver, model, :term:`mediator`, and connector. For more information, visit the `NUOPC website <https://earthsystemmodeling.org/nuopc/>`__.
NWP
Numerical Weather Prediction
Numerical Weather Prediction (NWP) takes current observations of weather and processes them with computer models to forecast the future state of the weather.
NWS
The `National Weather Service <https://www.weather.gov/>`__ (NWS) is an agency of the United States government that is tasked with providing weather forecasts, warnings of hazardous weather, and other weather-related products to organizations and the public for the purposes of protection, safety, and general information. It is a part of the National Oceanic and Atmospheric Administration (NOAA) branch of the Department of Commerce.
Parameterizations
Simplified functions that approximate the effects of small-scale processes (e.g., microphysics, gravity wave drag) that cannot be explicitly resolved by a model grid's representation of the earth. Common categories of parameterizations include radiation, surface layer, planetary boundary layer and vertical mixing, deep and shallow cumulus, and microphysics. Parameterizations can be grouped together into physics suites (such as the :term:`CCPP` physics suites), which are sets of parameterizations known to work well together.
Post-processor
Software that enhances the value of the raw forecasts produced by the modeling application to make them more useful. At :term:`NCEP`, the :term:`UPP` (Unified Post Processor) software is used to convert data from spectral to gridded format, de-stagger grids, interpolate data vertically (e.g., to isobaric levels) and horizontally (to various predefined grids), and to compute derived variables. Some types of post-processors, such as statistical post-processors, use historical information of previous runs and observations to de-bias and calibrate its output.
RT
Regression test
Tests to validate that software still performs as expected after a change. In general, RTs ensure that the code should produce the same results and performance, within predefined measures of variance. When a code change is designed to change results or performance, then a new baseline is created. From these baselines, regression tests determine whether a change has occurred.
SRW
SRW App
Short-Range Weather Application
The `Short-Range Weather Application <https://github.com/ufs-community/ufs-srweather-app>`__ is a UFS Application that targets predictions of atmospheric behavior on a limited spatial domain and on time scales from minutes out to about two days. It packages a prognostic atmospheric model (the UFS Weather Model), pre- and post-processing tools, and a community workflow.
spack-stack
The `spack-stack <https://github.com/NOAA-EMC/spack-stack>`__ is a collaborative effort between the NOAA Environmental Modeling Center (EMC), the UCAR Joint Center for Satellite Data Assimilation (JCSDA), and the Earth Prediction Innovation Center (EPIC). *spack-stack* is a repository that provides a Spack-based method for building the software stack required for numerical weather prediction (NWP) tools such as the `Unified Forecast System (UFS) <https://ufscommunity.org/>`__ and the `Joint Effort for Data assimilation Integration (JEDI) <https://jointcenterforsatellitedataassimilation-jedi-docs.readthedocs-hosted.com/en/latest/>`__ framework. *spack-stack* uses the Spack package manager along with custom Spack configuration files and Python scripts to simplify installation of the libraries required to run various applications. The *spack-stack* can be installed on a range of platforms and comes pre-configured for many systems. Users can install the necessary packages for a particular application and later add the missing packages for another application without having to rebuild the entire stack.
Suite Definition File (SDF)
An external file containing information about the
construction of a physics suite. It describes the schemes that are called, in which
order they are called, whether they are subcycled, and whether they are assembled
into groups to be called together
Suite
A collection of primary physics schemes and interstitial schemes that are known to work
well together
tracer
According to the American Meteorological Society (AMS) `definition <https://glossary.ametsoc.org/wiki/Tracer>`__, a tracer is "Any substance in the atmosphere that can be used to track the history [i.e., movement] of an air mass." Tracers are carried around by the motion of the atmosphere (i.e., by :term:`advection`). These substances are usually gases (e.g., water vapor, CO2), but they can also be non-gaseous (e.g., rain drops in microphysics parameterizations). In weather models, temperature (or potential temperature), absolute humidity, and radioactivity are also usually treated as tracers. According to AMS, "The main requirement for a tracer is that its lifetime be substantially longer than the transport process under study."
UFS
Unified Forecast System
The Unified Forecast System (UFS) is a community-based, coupled, comprehensive Earth
system modeling system. The UFS numerical applications span regional to global domains
and sub-hourly to seasonal time scales. The UFS is designed to support the :term:`Weather Enterprise` and to be the source system for NOAA's operational numerical weather prediction (:term:`NWP`) applications. For more information, visit https://ufscommunity.org/.
UFS_UTILS
The UFS Utilities repository (`UFS_UTILS <https://github.com/ufs-community/UFS_UTILS>`__) contains a collection of pre-processing programs for use with the UFS Weather Model and UFS applications. These programs set up the model grid and create coldstart initial conditions. The code is publicly available on the `UFS_UTILS <https://github.com/ufs-community/UFS_UTILS>`__ Github repository.
UPP
Unified Post Processor
The `Unified Post Processor <https://dtcenter.org/community-code/unified-post-processor-upp>`__ is the :term:`post-processor` software developed at :term:`NCEP`. It is used operationally to
convert the raw output from a variety of :term:`NCEP`'s :term:`NWP` models, including the :term:`FV3 dycore`, to a more useful form.
WW3
WWIII
WaveWatch III
WAVEWATCH III (WW3) is a community wave modeling framework that includes the latest scientific advancements in the field of wind-wave modeling and dynamics. The core of the framework consists of the WAVEWATCH III third-generation wave model (WAVE-height, WATer depth and Current Hindcasting), developed at NOAA/:term:`NCEP`. WAVEWATCH III differs from its predecessors in many important points such as governing equations, model structure, numerical methods and physical parameterizations. The model code is publicly available on GitHub at https://github.com/NOAA-EMC/WW3.
Weather Enterprise
Individuals and organizations from public, private, and academic sectors that contribute to the research, development, and production of weather forecast products; primary consumers of these weather forecast products.
WM
Weather Model
A prognostic model that can be used for short- and medium-range research and
operational forecasts. It can be an atmosphere-only model or be an atmospheric
model coupled with one or more additional components, such as a wave or ocean model.
The UFS Weather Model repository is publicly available on `GitHub <https://github.com/ufs-community/ufs-weather-model>`__.