J1.12
Validation of a rapidly relocatable prediction system (Formerly paper J1.13)
Germana Peggion, University of Southern Mississippi, Stennis Space Center, MS; and D. N. Fox and C. N. Barron
MODAS-NRLPOM is a scalable, portable, and rapidly relocatable system for nowcasting and short-term (2-day) forecasting in support of real-time naval operations. The analysis and forecasts can be available within an hour or two of a request, making the system useful in emergency situations. The Modular Ocean Data Assimilation System (MODAS) combines remote sensed data (altimetry and sea surface temperature) with in situ measurements to produce an analysis of the ocean that can be considerably more accurate than conventional climatology. Geostrophic velocities are derived from the T and S distributions, and the barotropic transport is computed from the computed dynamic height. The MODAS nowcast field provides initial and boundary condition for NRLPOM, a version of the Princeton Ocean Model (POM) that has been implemented at the Naval Research Laboratory (NRL) for real-time naval applications. NRLPOM principal attributes are a user-friendly interface, the inclusion of tidal flow, and the option for several initialization procedures (warm, cold, diagnostic and combination) and boundary conditions algorithms. The system also has the capability of 1-way coupling with other real-time operational models or 1-way nesting (NRLPOM to NRLPOM). The coupling/nesting procedure will be discussed using a triply-nested grid configuration. Real-time assimilative simulations from the global implementation of the Naval Coastal Ocean Model (NCOM) provide boundary conditions to a coarse, regional (from land to shelf-slope break) NRLPOM model that in turn provides the boundary conditions for a high-resolution coastal NRLPOM model. The boundary condition algorithms and the coupling/nesting procedure are robust and allow more accurate solutions for the inner high-resolution coastal domains. The real-time simulations are forced by the operational winds that are available for a given area. The system has been designed and implemented so that no data are ingested and assimilated during the forecasting simulations. We will present the results from real-time exercises in coastal domains. The goals are to evaluate MODAS and MODAS-NRLPOM nowcast fields and the system's forecasting capability. In general, MODAS analysis is sufficiently accurate to allow the dynamical model to spin-up the physics and provide more accurate solutions. Model-data comparison indicates that the system is usually accurate in predicting tidal flow, and coastal up-down- welling occurrences.
Joint Session 1, Estuarine and Coastal Ocean Forecasting-Joint Session with ECM and ERF (Please note some presentation times have been changed from the preliminary program published)
Wednesday, 7 November 2001, 9:00 AM-4:21 PM
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