Feature Oriented Regional Modeling System — FORMS An

Feature Oriented Regional Modeling System -- FORMS: An Overview Avijit Gangopadhyay University of Massachusetts Dartmouth Email: avijit@umassd. edu Funded by NASA and ONR

OUTLINE • Feature Oriented Regional Modeling System (FORMS) • Concept -- Initialization/Synthesis Methodology • Applications to different regions

Gulf Stream Front and Ring Analysis 2/11/02

Features in Western North Atlantic Deep Sea region (GSMR) • • • Gulf Stream Warm Core Rings Cold Core Rings Southern Recirculation Gyre Northern Recirculation Gyre Deep Western Boundary Current • Gangopadhyay et al. , 3 -part series in 1997: Journal of Atmospheric and Oceanic Tech. (14) 1314: 1365 Coastal region (GOMGB) • • Maine Coastal Current NEC Inflow GSC Outflow Jordan Basin Gyre Wilkinson Basin Gyre Georges Bank Gyre Tidal Mixing Front • Gangopadhyay et al. 2002 (Continental Shelf Res. In Press) Gangopadhyay and Robinson, 2002: DAO 36(2002) 201 -232 •

U(x, y, z)= (y){[UT(x)-UB(x)] (x, z) + UB(x)} T(x, y, z)=Ta(x, z)+ (x, z) (y) where, Ta(x, z)={[T 0(x)-Tb(x)] (x, z) +Tb}

=tan Where, m is the melding function:

In general, a coastal current (CC), a front (SSF) and an eddy/gyre (E/G) are represented by: CC: TM(x, η, z) =TMa(x, z)+ αM(x, z) M(η) SSF: Tss(x, y, z) = Tsh (x, z) + (Tsl (x, z) – Tsh(x, z)) ( , z) E/G: T(r, z) = Tc (z) - [Tc (z) - Tk (z) ] {1 -exp(-r/R)} where, TMa(x, z), Tsh (x, z) and Tc (z) are axis, shelf and core (η) = (0 W) ( , z) = ½ + ½ tanh[( -. Z)/ ]

Strategy for GOMGB MCC WBG JBG GBAG TMF SSF Inflow/Outflow

FORMS Protocol • Identify Circulation and Water mass features • Regional Synthesis -- Processes from a modeling perspective • Synoptic Data sets -- in-situ and satellite • Regional Climatology (Background Circulation) • OA (Climatology + Feature Models) • Simulation -- Nowcasting/Forecasting

FORMS Applications in Different Oceans • Western north Atlantic – Operational modeling in GOMGB – AFMIS-RFAC • Strait of Sicily – Dynamical analysis • Monterey Bay real-time forecasting with ROMS – AOSN-II in summer 2003 -- Upwelling • Brazil Current Meander-eddy-Upwelling System • Persian Gulf, Arabian Sea – Rapid response • Chilean Waters – Northern Humboldt Current – Biophysical modeling

Feature oriented methodology is applicable to ALL different Numerical Models • • MOM (Modular Ocean Model) POP (Parallel Ocean Program) ROMS (Regional Ocean Model System) POM (Princeton Ocean Model) MIT GCM HOPS (Harvard Ocean Prediction System) Finite Element / Finite Volume models It is an Initialization and Assimilation Methodology

Strait of Sicily Feature Oriented Regional Modeling Set Up

The Brazil Current System

Meander-eddy-Upwelling System

The Brazil Current Structure

The Hardest Work of All!! SEC IWBC

Dynamical Features in BCS • Brazil Current (Surface (0 -150 m) – 2 branches • Bifurcating SEC around the Abrolhos Bank and Vitoria ridge – Pycnocline (150 -500 m)) • IWBC + NADW (DWBC) • Cabo Sao Tome eddy • Cabo Frio eddy • Vitoria eddy • Upwelling regions • Instability-generated Vortex dipoles in Santos Bight • Fresh water influx in the shelf between the coast and the Brazil Current

Southern California Coastal region

The California Current System

The Pacific basin-scale ROMS configuration at 50 -km spatial resolutions will provide the required boundary conditions for the regional ROMS off the U. S. West coast.

Sea surface temperature simulated by ROMS. The 3 -level ROMS domains are displayed.

Snapshot of sea surface temperature (left) and surface current (right) simulated by the 1. 5 -km ROMS. Model 500 m, 1000 m, 1500 m, and 2000 m isobaths are displayed (left).

Humboldt Current System

The Peru-Chile Current System

Shallow water feature models • Use of ‘intelligent observations’ that are important to resolve the scales and represent the underlying dynamical processes • Not only temperature-salinity structure, but include first-order dynamics • Process-oriented feature models

Upwelling • Wind speed and direction at highest available resolution from Quik. Scat • Mixed-layer depth estimate from MODIS • Infer the Ekman Current in the Upper Mixed layer • Additional baroclinic currents may be added for coastally trapped waves or alongshore currents • Monterey Bay in Summer 2003, Vietnamese shelf in summer 2003, Brazil Current - Cape Frio upwelling region in austral summer 2003.

Transient feature models • Coastal filaments, jets, squirts and eddies • Automated gradient-detection algorithm (Cayula and Cornillon, 1995) • Small scales (1 -100 km) and short-life (20 -40 days) • Spatial and temporal dependence of FM parameters • Low vs. high chlorophyll regions (Chan, 1999)

CONCLUSIONS • Developing FORMS is a pre-requisite for Synoptic modeling system • FORMS is unique for each region • Shallow water FORMS are very important for accurate prediction of bio-physically active systems • FORMS is independent of the numerical modeling system (POM, ROMS, MOM, POP, HOPS etc. )

OBJECTIVELY BASED FEATURE MODEL • Wilkinson basin water masses • Brooks June 1982 data • Cluster model of water masses • EOF vertical analysis • Feature model of vertical temperature and salinity

Brooks 1982 June survey in Wilkinson Basin

T, S Diagram

CLUSTER MODEL Distance function where

Water mass Ellipsoids

Explained Percent Variance No. of Modes Included

The 1997 PRIMER IV Field experiment To-beanalyzed via Cluster-EOF analysis with NRL-Stennis team

Feature tracking in shallow coastal regions • • • MODIS instrument on Terra and Aqua Resolution ~ 250 meters (1 -km globally) Temperature precision – 0. 3 -0. 5 K Navigational accuracy – 50 meters per pixel Moving mesh algorithm (Rowley and Ginis, 1999) ; Wavelet approach (Liu et al. , 2002) • Monterey Bay application – PCCS?

MODIS chlorophyll on July 23, 2002 for southern California from Terra (left) at 1815 GMT, and the same field from Aqua (right) at 2115 GMT. A feature-tracking algorithm that uses the chlorophyll field as tracer will deduce the surface currents, which can be assimilated in the Navy’s modeling system. [Courtesy: Ron Vogel, http: //www. modis-ocean. gsfc. nasa. gov/whatsnew. html]