Hindcast Simulations of Hydrodynamics in the Northern Gulf of Mexico

Using the FVCOM Model

Zizang Yang1, Eugene Wei1, Aijun Zhang2, Richard Patchen1 and Frank Aikman1

1 Coast Survey Development Laboratory, NOAA/NOS, Silver Spring, MD2 Center for Operational Oceanographic Products and Services (CO-OPS), NOAA/NOS, Silver Spring, MD

Northern GOM

- Maritime navigational safety: water level, velocity and T/S - Support NOS Port OFS development: open boundary conditions - Ecosystem related modelings: HAB, Hypoxia, etc

Introduction

NGOFS domain

NGOFS

- NOAA/NOS Northern Gulf of Mexico Nowcast/Forecast System

- Scheduled to start operational runs on April 1, 2012!

Outline

-Numerical Methods -Setup of Hindcast simulations -Results -Model-data comparisons-Summary & Future work

Methods

- Finite Volume Coastal Ocean Model (FVCOM)Unstructured, 3-D prognostic, hydrostatic

- Forcing Open ocean boundary Meteorological forcing River discharge

- Model grid Horizontal resolution: 150 m–11 km Vertical co-ordinate: 41 sigma levels

H < 200 m: evenly spaced H > 200 m: top/bottom 5 layers: constant 5-m spacing

middle layers: evenly spaced

Nodes: 90,267Elements: 174,474

Bathymetry

Forcing Terms Period 1(July’ 08-Sept’09)

Period 2(Sept.’ 10-March’ 11)

Open ocean boundary(wl, T, S, u, v)

(Tidal + nontidal)

Tidal: ADCIRC EC2001 tidal databaseSubtidal: one-way coupling with NOAA/NOS NGOM

Tidal: ADCIRC EC2001 tidal databaseSubtidal: one-way coupling with Navy G-NCOM (Region 1)

Surface forcing

(U10, Tair, Patm, RH, SW, LW)

NARR- 3 hourly

- 30-km resolution

NAM- 3 hourly

- 10-km resolution

River dischargesUSGS river gauge data

daily averageddischarge rate, T, S

USGS river gauge data - daily averaged

discharge rate, T, S

Two periods of Hindcast Simulations

Coupling with Regional Ocean Models

- NOAA/NOS NGOM- 1st hindcast Period: July’ 08-Sept’

09

- Bathymetry on open ocean boundary- Non-tidal water level, u, v, and T/S

- Navy Global NCOM (region 1) - 2nd hindcast Period: Sept.’ 08-March’

11

Results

-Consistency with coupled NGOM/NCOM results-Data-model comparisons

-Data: TABS, NWLON, C-MIST-Time series: water level, (u,v), and T/S

TABS - Texas Automated Buoy SystemNWLON - NOAA/NOS National Water Level Observation NetworkC-MIST – NOAA/NOS Currents Measurement Interface for the Study of Tides

T (deg C) (10-m depth)

Consistency with NGOM Results

2008-09-01 T00:00

S (psu) (10-m depth)

NGOM NGOFS

2009-04-01 T00:00

NGOM NGOFS

2008-09-01 T00:00

NGOM NGOFS2009-04-01 T00:00

NGOM NGOFS

T (deg C) (10-m depth)

Consistency with NCOM Results

2010-11-01 T00:00

NCOM NGOFS

NCOM NGOFS

2011-03-01 T00:00

S (psu) (10-m depth)2010-11-01 T00:00 2011-03-01 T00:00

NCOM NGOFS

NCOM NGOFS

1st Hindcast – Water Levels & Currents C-1

C-2

Wl-1

Water level

Wl-2Wl-3

Sta: wl-2

Sta: wl-3

Sta: wl-1 b: obsr: ngofs

Sta: C-1

Sta: C-2 Speed (m/s)

b: obs r: ngofs

C-1

C-2

C-1 C-2Currents

Speed (m/s)

Dir (deg from N.)

Dir (deg from N.)

T

Sta A

Sta B

Sta C

S

Sta A: A

Sta B

Sta C

AB

C

1st Hindcast – T/S

Blue: observations Red: NGOFS

2nd Hindcast - Water Level & Currents

Sta A

Sta B

Sta C

Sta D

CD

A BB

A

Sta A

Sta B

black: obs red: NGOFS

black: obs red: NGOFS Speed(m/s)

Direction (deg from N.)

Speed(m/s)

Direction (deg from N.)

2nd Hindcast: Temperature (deg C)

C DA

B

Sta B

Sta C

Sta D

Sta E

Sta F

E F

Sta A

black: obs r: NGOFS black: obs r: NGOFS

2nd Hindcast: Salinity (psu)

C

B

A

D

Sta A

Sta C

Sta B

Sta D

black: obs red: NGOFS

Summary

- Two hindcast simulations 1 period: July’ 08-Sept’ 09

coupled with NOAA NGOM 2 period: Sept.’ 10-March’ 11

coupled with Navy NCOM

- Successful coupling with basin-scale models- Favorable model-data agreement

Future Work

-Continue skill assessments TABS, NWLON, C-MIST, CTD Satellite SST

-Optimize model parameter setup

Questions ?