hindcast simulations of hydrodynamics in the northern gulf of mexico using the fvcom model

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 ?