11. Glossary


Model agnostic, vetted, collection of codes containing atmospheric physical parameterizations and suites for use in NWP along with a framework that connects the physics to host models


The infrastructure that connects physics schemes with a host model; also refers to a software repository of the same name


The pool of CCPP-compliant physics schemes; also refers to a software repository of the same name

Dynamic CCPP build

A CCPP build type in which the CCPP-Framework and CCPP-physics libraries are dynamically linked to the executable and all CCPP-compliant schemes available in the library can be invoked at runtime. This build type is available for both the SCM and the UFS Atmosphere

“Fast” physics

Physical parameterizations that require tighter coupling with the dynamical core than “slow” physics (due to the approximated processes within the parameterization acting on a shorter timescale) and that benefit from a smaller time step. The distinction is useful for greater accuracy, numerical stability, or both. In the UFS Atmosphere, a saturation adjustment is used in some suites and is called directly from the dynamical core for tighter coupling


A set of physics schemes within a suite definition file (SDF) that are called together without intervening computations from the host application

Group cap

Autogenerated interface between a group of physics schemes and the host model. They are used only in the static CCPP build, and effectively replace the code from CCPP-Framework that provides the flexibility of the dynamic CCPP build

Host model/application

An atmospheric model that allocates memory, provides metadata for the variables passed into and out of the physics, and controls time-stepping

Interstitial scheme

A modularized piece of code to perform data preparation, diagnostics, or other “glue” functions that allows primary schemes to work together as a suite. They can be categorized as “scheme-specific” or “suite-level”. Scheme-specific interstitial schemes augment a specific primary scheme (to provide additional functionality). Suite-level interstitial schemes provide additional functionality on top of a class of primary schemes, connect two or more schemes together, or provide code for conversions, initializing sums, or applying tendencies, for example.

Multi-suite static CCPP build

A static CCPP build type in which a set of physics suites is specified at compile time from which one can be chosen at runtime.


The NOAA Environmental Modeling System - a software infrastructure that supports NCEP/EMC’s forecast products. The coupling software is based on ESMF and the NUOPC layer.


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.


The representation, in a dynamic model, of physical effects in terms of admittedly oversimplified parameters, rather than realistically requiring such effects to be consequences of the dynamics of the system (AMS Glossary)

Physics cap

Autogenerated interface between an individual physics scheme and the host model. Used only in the dynamic CCPP build

Primary scheme

A parameterization, such as PBL, microphysics, convection, and radiation, that fits the traditionally-accepted definition, as opposed to an interstitial scheme


Compiler flags used by NCEP for operational runs of the UFS Atmosphere and by EMC for regression tests of the code


Compiler flags used by EMC to guarantee reproducibility of the UFS Atmosphere code


A CCPP-compliant parameterization (primary scheme) or auxiliary code (interstitial scheme)


Suite Definition File (SDF) is 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


A collection of physics schemes that do not share memory (e.g. fast and slow physics)

“Slow” physics

Physical parameterizations that can tolerate looser coupling with the dynamical core than “fast” physics (due to the approximated processes within the parameterization acting on a longer timescale) and that often use a longer time step. Such parameterizations are typically grouped and calculated together (through a combination of process- and time-splitting) in a section of an atmospheric model that is distinct from the dynamical core in the code organization


Variable names based on CF conventions (http://cfconventions.org) that are uniquely identified by the CCPP-compliant schemes and provided by a host model

Static CCPP build

A build type in which the CCPP-Framework and the CCPP-physics libraries are statically linked to the executable and only the suites determined at compile time can be invoked at runtime. This build type is only available for the UFS Atmosphere


Executing a physics scheme more frequently (with a shorter timestep) than the rest of the model physics or dynamics


A collection of primary physics schemes and interstitial schemes that are known to work well together

Suite cap

Autogenerated interface between an entire suite of physics schemes and the host model. They are used only in the static CCPP build and consist of calls to autogenerated group caps. They may be used to call an entire suite at once or to call a specific group within a physics suite


A Unified Forecast System (UFS) is a community-based, coupled comprehensive Earth system modeling system. The UFS numerical applications span local to global domains and predictive time scales from sub-hourly analyses to seasonal predictions. It is designed to support the Weather Enterprise and to be the source system for NOAA’s operational numerical weather prediction applications

UFS Atmosphere

The atmospheric model component of the UFS. Its fundamental parts are the dynamical core and the physics

UFS Weather Model

Global meduim-range, weather-prediction model previously known as NEMSfv3gfs or FV3GFS used to create forecasts.


Virtual Laboratory - a service and information technology framework, that enables NOAA employees and their partners to share ideas, collaborate, engage in software development, and conduct applied research (https://www.nws.noaa.gov/mdl/vlab/)

.xsd file extension

XML schema definition