Improving the GFDL/URI Improving the GFDL/URI Coupled Hurricane-Ocean Coupled Hurricane-Ocean

Model for Transition to OperationsModel for Transition to Operations

Isaac GinisIsaac GinisUniversity of Rhode IslandUniversity of Rhode Island

B. Thomas, URI I-J. Moon, URIA. Falkovich, NCEP M. Bender, GFDL

Support is provided by JHT/USWRP

GFDL/URI Coupled Model

Implemented to operations at NCEP in 2001 after Implemented to operations at NCEP in 2001 after three years of near-real time testing in 1998-2000three years of near-real time testing in 1998-2000

Improvements implemented in 2003: Improvements implemented in 2003: - New ocean model domain configurations New ocean model domain configurations - Ocean coupling over entire ocean domains Ocean coupling over entire ocean domains - Gulf Stream and Loop Current data assimilationGulf Stream and Loop Current data assimilation

Examples of the Coupled Model ForecastsHurricane Isabel Initial Time: 00 UTC 15 Sept, 2003

Sea Surface CurrentsSea Surface Currents Sea Surface TemperatureSea Surface Temperature

Ongoing Efforts Toward Future Improvements

Ocean coupling in the Eastern Pacific basinOcean coupling in the Eastern Pacific basin

High resolution version of the GFDL modelHigh resolution version of the GFDL model

Air-sea flux parameterizationAir-sea flux parameterization

Coupled hurricane-wave-ocean systemCoupled hurricane-wave-ocean system

Hurricane IGNACIO 22-27 AUG, 2003

Hurricane Ignacio GFDL Model Forecast (12Z 24 AUG, 2003)

Red - OperationalGreen - CoupledBlack - Observed

High-resolution Version of the High-resolution Version of the GFDL/URI Coupled ModelGFDL/URI Coupled Model

• Goal: To better resolve the hurricane core region, especially in major hurricanes

• Grid configuration:

1/2o (stationary); 1/6o and 1/12o (movable)

Hurricane Isabel, Sept 8 12Z, 2003

Operational GFDL model

High resolution GFDL model

3-Nest

2-Nest

Hurricane Isabel (2003)kts

SHIPSHigh Res

GFDL

Air-Sea Fluxes in High Wind Conditions

Behavior of Cd and Ch in the GFDL model

?

Wind Speed (m/s)

Cd

Ch

Idealized Sensitivity Experiments

New Coupled Wind-Wave Model

young waves

mature waves

20 30 50

U10 (m /s)40

0

Powell et al. (2003) Large & Pond (1981)W W 3 (upper and lower bound)

3

1

Our results (upper and lower bound)

5

4

2

CD

* 1

000

Bulk, 0.0185

WW3

CWW

Wave Field in a Hurricane

GFDL(WRF)Hurricane Model

NCEPWAVEWATCH III

Flux

Wind &Air Temp.

Atmosphere

Ocean Waves

Currents,

Wave Boundary Model

SST

Wave Spectra

Flux

POM(HYCOM)

Wind &Air Temp.

Flux

GFDLHurricane Model

POM

SST &Current

SST

Flux

Atmosphere

Ocean

Elevations, & SST

Operational GFDL ModelOperational GFDL Model Future Coupled Hurricane-Wave-Ocean ModelFuture Coupled Hurricane-Wave-Ocean Model

Plans for Operational Implemantion

• Ocean coupling in the Eastern Pacific is planned for operational implementation in 2004

• The high resolution GFDL coupled model will be tested in near real-time in 2004 is planned for operational implementation in 2005

• The coupled GFDL hurricane-wave-ocean model is being developed