Introduction In the next few slides you will get an overview of the types of models that the Navy is using – analysis systems, tidal models and the primitive.

IntroductionIn the next few slides you will get an overview of the types of models that the Navy is using – analysis systems, tidal models and the primitive equation models. This brief introduction will be followed by an in-depth presentation on each set of models. The material for each model is presented in a consistent way. Each model will have a slide on each of the modeling issues we discussed in the numerical modeling portion of the course: domain, grid system, boundary conditions, data assimilation and implementation, plus a look at the output.

Operational vs Research Mode

Operational: find the optimal configuration

for good solutions everywhere.

Research: find the configuration for the best

solution for a given problem.

Courtesy of Germana Peggion (USM)

Atm.Data

Atm.Data

OceanData

OceanData

Analysis

Forecast

Analysis

Forecast

Nesting/BoundaryConditions

2/10/01

Analysis Analysis

Forecast

Nesting/BoundaryConditionsForecast

Global Coastal & Harbor (Fixed & Relo.)

OceanApplicationsIMAT, SAR, Dispersion

Other MUSW TDAs

OceanApplicationsIMAT, SAR, CB Dispersion

SpecOp, AUV, MUSW TDAs

Coupling Coupling

NRL Ocean Dynamics & Prediction

Courtesy of John Harding, NRL-SSC

Global to Littoral Nested Strategy

NCOM 1/8 SST 8-27-2000 0000 GMT nowcast5/15/00

SST

Increasing ResolutionConsistent Fields

Courtesy of John Harding, NRL-SSC

NavalGlobalOcean

Prediction

Navy Ocean Circulation PredictionExpected Evolution

NLOM/NCOM 1.5POP at FNMOC?

NavyCoastalOcean

Prediction

SWAFS 1.0 ReloPOM ADCIRC

SWAFS-Next based on SWAFS 1.0,

NCOM 1.X & TOMS Community Effort)

NLOM/NCOM 1.XPOP?

SWAFS-Next II based on

NCOM 1.X/TOMS/HYCOM/Finite Element/ Nearshore Wave

CommunityEfforts)

HYCOM(Hybrid

Coordinate Community

Model)

FY 02-03 FY 04-06 FY 07-10

NavyHarbor

Prediction

ADCIRCReloPOM &/or

Commercial …

Baroclinic FEReloPOM &/orCommercial …

Courtesy of John Harding, NRL-SSC

DATA ASSIMILATION SYSTEMS OCEAN MVOI 3-Dimensional Ocean Multi-Variate Optimum Interpolation System

MODAS Modular 3-Dimensional Ocean Data Assimilation System OTIS Optimum Thermal Interpolation System

TIDE MODELS

ADCIRC Advanced Hydrodynamic Circulation Model for shelves, coasts, and

estuaries PCTides Rapidly Relocatable Tidal Model

GENERAL CIRCULATION MODELS

NLOM Deep Ocean Mesocale Prediction (global) NCOM Upper Ocean & Coastal Ocean Prediction (global initially) SWAFS Coastal Ocean Prediction (various fixed regions & nests)

ReloPOM Rapidly Relocatable Ocean Prediction (regional & nests) SURFACE MIXED LAYER MODEL

TOPS Upper Ocean Mixed Layer Forecast (global & fixed regions)

Adapted from Bill Burnett, CNMOC 9/24/01

Essential elements of the Navy operational ocean circulation and tide models

There are some software systems that the Navy uses to analyze, interpret, map and/or project data and derive estimated currents, which do not predict what the currents will be in the future. They sometimes refer to these as analysis systems, as opposed to models. These include OTIS, MODAS and MVOI.

Analysis Systems

The Navy sometimes uses the term “tide models” to designate those numerical ocean models being run primarily for the purpose of predicting tidal heights and/or currents. At this time, the tide models used by the Navy are run in a 2D mode (no variation in the vertical dimension). By definition these models must include tidal forcing, but they may also include other types of forcing, just as other ocean circulation models used by the Navy may include tidal forcing.

Tide Models

Primitive equation models

These are the most sophisticated type of ocean circulation model, including more of the physics than the analysis systems and shallow water equation models. While their increased complexity makes them applicable to a broader class of applications, and should result in more accurate solutions, it can also be more difficult to diagnose their behavior and to understand how various model choices affect the results.

“Mixed layer” models

We will only consider mixed layer models applied to the upper part of the ocean, although you can also have mixed layers near the bottom of the ocean. Mixed layer models are 1D models that can help us understand how currents, temperature and density in the upper ocean evolve under the influence of wind forcing and heat exchange with the atmosphere. By themselves they do not include any effects due to coastal boundaries, tides, fronts etc.