Delicacy, Imprecision, and Uncertainty of Oceanic Simulations: An Investigation with the Regional Oceanic Modeling System (ROMS)
Abstract
In this project our long-term goal is to determine the ways and degrees to which realistically complex oceanic and atmospheric simulation models have an irreducible imprecision, hence an irreducible uncertainty in their analysis and forecast products. This goal is a natural accompaniment to the goal of continuing the evolution of the Regional Oceanic Modeling System (ROMS) as a multi-scale, multi-process model and utilizing it for studying a variety of oceanic phenomena that span a scale range from turbulence to basin-scale circulation. Primary objectives are code improvements and oceanographic simulation studies with ROMS, as well as with Large Eddy Simulation (LES) for boundary layer turbulence, with measurement comparisons where feasible. The targeted phenomena are submesoscale wakes, fronts, and eddies; shelf and near shore currents; internal tides; regional, Pacific and Atlantic eddy-resolving circulations and their low-frequency variability; mesoscale ocean-atmosphere coupling; and planetary boundary layers with surface gravity waves. A parallel in this project objective is to establish the characteristics of model delicacy and uncertainty in ROMS and other models for realistic simulation of highly turbulent flows, as an intrinsic model contribution to analysis and forecast errors that, in principle, is distinct from unskillful model design choices and input data errors that lead to poor solutions. The premise is that defensible alternative model designs - in parameter values, subgrid-scale parametrizations, resolution, algorithms, topography, and forcing data - may often provide a range of answers comparable to the model-measurement discrepancies. We hypothesize that some appreciable part of the model-to-measurement and model-to-model differences may be irreducibly inherent in the mathematical structure of modern simulation models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 2013
- Accession Number
- ADA601140
Entities
People
- A. F. Shchepetkin
- James C. McWilliams
- M. Jeroen Molemaker
Organizations
- University of California, Los Angeles