A Technical Description of the NRL Adjoint Modeling System

Abstract

This report describes the tangent linear model (TLM), and the accompanying adjoint model, for the Navy Operational Global Atmospheric Prediction System (NOGAPS) spectral forecast model. Details are given for the linearization of the model equations, the development of the matrix transpose operators that constitute the adjoint model, and a discussion of the self-adjoint properties of the spherical harmonic transforms, unique to spectral models such as NOGAPS. A powerful application of the TLM and adjoint models, the calculation of singular vectors about a basic state trajectory forecast of the non-linear NOGAPS model, is also described. Some illustrative examples of singular vector and adjoint model calculations are given. Full model codes are available by request from the author.

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Document Details

Document Type
Technical Report
Publication Date
Apr 01, 1997
Accession Number
ADA330960

Entities

People

  • Thomas E. Rosmond

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Algorithms
  • Applied Mathematics
  • Boundaries
  • Boundary Layer
  • Computational Science
  • Computations
  • Computer Programming
  • Coordinate Systems
  • Eigenvalues
  • Equations
  • Equations Of Motion
  • Grids
  • Heat Energy
  • Latent Heat
  • Linear Systems
  • Stratified Fluids
  • Weather Forecasting

Readers

  • Computer Science.
  • Linear Algebra
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers