Accession Number:

ADA619044

Title:

Development and Testing of a Coupled Ocean-atmosphere Mesoscale Ensemble Prediction System

Descriptive Note:

Journal article

Corporate Author:

NAVAL RESEARCH LAB MONTEREY CA MARINE METEOROLOGY DIV

Report Date:

2011-06-28

Pagination or Media Count:

20.0

Abstract:

A coupled ocean atmosphere mesoscale ensemble prediction system has been developed by the Naval Research Laboratory. This paper describes the components and implementation of the system and presents baseline results from coupled ensemble simulations for two tropical cyclones. The system is designed to take into account major sources of uncertainty in 1 non-deterministic dynamics, 2 model error, and 3 initial states. The purpose of the system is to provide mesoscale ensemble forecasts for use in probabilistic products, such as reliability and frequency of occurrence, and in risk management applications. The system components include COAMPS Coupled Ocean Atmosphere Mesoscale Prediction System and NCOM Navy Coastal Ocean Model for atmosphere and ocean forecasting and NAVDAS NRL Atmospheric Variational Data Assimilation System and NCODA Navy Coupled Ocean Data Assimilation for atmosphere and ocean data assimilation. NAVDAS and NCODA are 3D-variational 3DVAR analysis schemes. The ensembles are generated using separate applications of the Ensemble Transform ET technique in both the atmosphere for moving or nonmoving nests and the ocean. The atmospheric ET is computed using wind, temperature, and moisture variables, while the oceanographic ET is derived from ocean current, temperature, and salinity variables. Estimates of analysis error covariance, which is used as a constraint in the ET, are provided by the ocean and atmosphere 3DVAR assimilation systems. The newly developed system has been successfully tested for a variety of configurations, including differing model resolution, number of members, forecast length, and moving and fixed nest options.

Subject Categories:

  • Meteorology
  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE