Identification

Title

Introduction to Adjoint Techniques and the MM5 Adjoint Modeling System

Abstract

Adjoint models are increasingly applied to many problems in meteorology and oceanography. The adjoint model of MM5 is a tool which effectively computes the gradient (or a Gateau-derivative) of any MM5 forecast aspect with respect to the model's control variables, which consist of model initial conditions, boundary conditions, and model parameters that define the physical and numerical conditions of the integration. Different applications of adjoint models in meteorology are briefly reviewed and their mathematical formulae are provided which illustrate how the adjoint model and/or tangent linear model are used in each application. Then we describe the mathematical and numerical formulation used in developing the adjoint version of MM5. The possibility of carrying out optimal control of lateral boundary condition in addition to the initial condition, the restart of minimization procedure, the proper handling of disk space for large problems, and the choice of different basic state update frequencies are provided. Finally, problems that might arise in the practical coding of the adjoint of a numerical model are summarized. A number of rules for the practical coding of tangent linear and adjoint models, along with various examples, are presented. The problems raised by the development and maintenance of adjoint codes are also discussed.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d7f18z4x

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Keyword set

keyword value

EARTH SCIENCE SERVICES > MODELS > WEATHER RESEARCH/FORECAST MODELS

originating controlled vocabulary

title

U.S. National Aeronautics and Space Administration Global Change Master Directory

reference date

date type

revision

effective date

2021-09-17

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

1997-01-01T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Copyright Author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata date

2023-08-18T18:05:48.281179

Metadata language

eng; USA