9. Glossary

advect

To transport substances in the atmostphere by advection.

advection

According to the American Meteorological Society (AMS) definition, 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 (AQM) is a UFS Application that dynamically couples the Community Multiscale Air Quality (CMAQ) model with the UFS Weather Model through the 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., advection and diffusion) of all chemical species are handled by the UFS Weather Model as tracers.

CCPP

The Common Community Physics Package is a forecast-model agnostic, vetted collection of code containing atmospheric physical parameterizations and suites of parameterizations for use in Numerical Weather Prediction (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 repository (CDEPS) contains a set of NUOPC-compliant data components and ESMF-based “stream” code that selectively removes feedback in coupled model systems. In essence, CDEPS handles the static Data Atmosphere (DATM) integration with dynamic coupled model components (e.g., 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 CMEPS mediator. The fields sent to the 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.

CESM

The Community Earth System Model (CESM) is a fully-coupled global climate model developed at the National Center for Atmospheric Research (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 UFS_UTILS.

CICE
CICE6
Sea Ice Model

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 advection of different state variables; and a vertical physics package called “Icepack”.

CMAQ

The Community Multiscale Air Quality Model (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 (CMEPS) is a NUOPC-compliant mediator used for coupling Earth system model components. It is currently being used in NCAR’s Community Earth System Model (CESM) and NOAA’s subseasonal-to-seasonal (S2S) coupled system. More information is available in the CMEPS Documentation.

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.

DATM

DATM is the Data Atmosphere component of 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 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.

dycore
dynamical core

Global atmospheric model based on fluid dynamics principles, including Euler’s equations of motion.

EMC

The Environmental Modeling Center is one of NCEP’s nine centers and leads the National Weather Service’s modeling efforts.

ESMF

Earth System Modeling Framework. 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 dynamical core (dycore). Developed at NOAA’s Geophysical Fluid Dynamics Laboratory (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 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) and the Joint Effort for Data assimilation Integration (JEDI) framework.

HAFS

The Hurricane Analysis and Forecast System (HAFS) is a UFS application for hurricane forecasting. It is an 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) 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 for more information on using the model. The HYCOM model code is publicly available on GitHub.

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. Currently, MOM6 code and an extensive suite of test cases are available under an open-development software framework. Although there are many public forks of MOM6, the NOAA EMC fork is used in the UFS Weather Model.

MRW
MRW App

The Medium-Range Weather Application 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.

NCEP

National Centers for Environmental Prediction (NCEP) is a branch of the National Weather Service and consists of nine centers, including the Environmental Modeling Center. More information can be found at https://www.ncep.noaa.gov.

NCEPLIBS

The software libraries created and maintained by NCEP that are required for running chgres_cube, the UFS Weather Model, and the UPP. They are included in the HPC-Stack and in spack-stack.

NCEPLIBS-external

A collection of third-party libraries required to build NCEPLIBS, chgres_cube, the UFS Weather Model, and the UPP. They are included in the HPC-Stack and in spack-stack.

NEMS

The NOAA Environmental Modeling System is a common modeling framework whose purpose is to streamline components of operational modeling suites at NCEP.

NG-GODAS

Next Generation-Global Ocean Data Assimilation System. NG-GODAS is a UFS Weather Model configuration that couples ocean (MOM6), sea ice (CICE6), and Data Assimilation (DA) capabilities with the DATM component of CDEPS.

NUOPC
National Unified Operational Prediction Capability

The National Unified Operational Prediction Capability 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 NUOPC Layer “defines conventions and a set of generic components for building coupled models using the Earth System Modeling Framework (ESMF).” NUOPC applications are built on four generic components: driver, model, mediator, and connector. For more information, visit the NUOPC website.

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 (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 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 NCEP, the 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.

SRW
SRW App
Short-Range Weather Application

The Short-Range Weather Application 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 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) and the Joint Effort for Data assimilation Integration (JEDI) 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, 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 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 Weather Enterprise and to be the source system for NOAA’s operational numerical weather prediction (NWP) applications. For more information, visit https://ufscommunity.org/.

UFS_UTILS

The UFS Utilities repository (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 Github repository.

UPP
Unified Post Processor

The Unified Post Processor is the post-processor software developed at NCEP. It is used operationally to convert the raw output from a variety of NCEP’s NWP models, including the 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/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.