Sensitivity Analysis of Limited Area Ocean Model

Abstract

The boundary data for a data assimilation problem for a limited-area ocean model can either be supplied by its global model or from observations interpolated from a conventional observing network. In this study, the sensitivity of the ocean model to variations in the boundary data is investigated. Additionally, the authors look at how predictions of wave height are affected by variations in basin depth. Two models are used to carry out the analyses: a large-scale ocean circulation model and a combined wave refraction diffraction model (Ref/Dif 1 model). The large-scale circulation model is used to implement the limited-area ocean model. Results show that the accuracy and availability of boundary data affect the model's predictions. For the limited-area model, error was observed in the solution even when all the boundary data were passed to the limited-area model. This hints that on top of the need for accurate boundary data, the initial data might need to be initialized by the bounded derivative method, for example, to ensure that error does not propagate into the solution. It has been shown that variability in the bottom topography does not affect the results obtained from Ref/Dif 1. The density plots of the wave height and water depth concur with the mean and variance plots of the wave height and bottom topography. Furthermore, a comparison of the mean solution to the deterministic solution shows that the random bottom topography had little effect on the Ref/Dif 1 results. (33 figures, 12 refs.)

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Document Details

Document Type
Technical Report
Publication Date
Aug 01, 2002
Accession Number
ADA417044

Entities

People

  • Dubar K. Kamara

Organizations

  • Johns Hopkins University

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Computational Science
  • Differential Equations
  • Diffraction
  • Dissipation Factor
  • Equations
  • Equations Of Motion
  • Frequency
  • Grids
  • Layers
  • Ocean Currents
  • Ocean Waves
  • Partial Differential Equations
  • Random Variables
  • Shallow Water
  • Stochastic Processes
  • Water Waves

Readers

  • Coastal Oceanography
  • Computational Modeling and Simulation
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers