Daily Inter-Annual Simulations of SST and MLD using Atmospherically Forced OGCMs: Model Evaluation in Comparison to Buoy Time Series

Abstract

A systematic methodology for model-data comparisons of sea surface temperature (SST) and mixed layer depth (MLD) is presented using inter-annual simulations from an ocean general circulation model (OGCM), the Naval Research Laboratory (NRL) Layered Ocean Model (NLOM), over 1980-1998. The model-data comparisons performed here are applicable to other OGCMs and are sufficiently detailed to allow easy comparison of results from other models with NLOM, including statistics at specific buoy locations in specific years. There are three model configurations: coarse resolution (1/2 deg global) and fine resolution (1/8 deg global and 1/16 deg Pacific). These are used to assess the sensitivity to OGCM resolution, including the impact of increasing non-determinicity due to flow instabilities in the 1/8 deg marginally eddy-resolving and 1/16 deg fully eddy-resolving simulations. In addition, sensitivity to the choice of atmospheric forcing product is investigated. For all three models the atmospheric forcing is from the European Centre for Medium-Range Weather Forecasts (ECMWF) during 1980-1998, and for the 1/16 deg Pacific configuration only the forcing from the Fleet Numerical Meteorology and Oceanography Center (FNMOC) Navy Operational Global Atmospheric Prediction System (NOGAPS) during 1990-1998 is also used. Availability of NOGAPS thermal forcing begins in 1998. Daily averaged buoy time series from the National Data Buoy Center (NDBC) and the Tropical Atmosphere Ocean (TAO) array are used for inter-annual evaluation of these atmospherically forced OGCMs with no assimilation of SST data and no date-specific assimilation of any data type. For the purpose of model evaluation several statistical metrics are calculated comparing buoy and model time series: mean error (ME), root-mean-square difference (RMSD), correlation coefficient (R), non-dimensional skill score (SS), and normalized RMSD (NRMSD).

Open PDF

Document Details

Document Type
Technical Report
Publication Date
Jan 30, 2008
Accession Number
ADA476551

Entities

People

  • A. Birol Kara
  • Harley E. Hurlburt

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies
  • Materials and Manufacturing Processes
  • Sensors

DTIC Thesaurus Topics

  • Arabian Sea
  • Assimilation
  • Atmospheres
  • Availability
  • Boundary Layer
  • Data Sets
  • Grids
  • Heat Flux
  • Military Research
  • Oceanography
  • Oceans
  • Pacific Ocean
  • Sea Surface Temperature
  • Simulations
  • Statistics
  • Surface Temperature
  • Topography

Fields of Study

  • Environmental science

Readers

  • Approximation Theory.
  • Ocean-Atmosphere Mesoscale Modeling, Data Assimilation, and Flux Boundary Layers