1. Coupled Atmosphere-Wave-Ocean Modeling Experiments in Hurricanes
Shuyi S. Chen Joseph Tenerelli, Wei Zhao, Mark Donelan Rosenstiel School of Marine and Atmospheric Science University of Miami
26th Conference on Hurricanes and Tropical Meteorology, Miami, 3-7 May 2004

2. Coupled Atmosphere-Wave-Ocean Modeling
CBLAST-Hurricane
Coupled Atmosphere-Wave-Ocean Modeling
Objective - To develop air-sea coupling parameterizations for fully coupled, high-resolution atmosphere-wave –ocean modeling systems for hurricane prediction.
Wind-Wave Coupling
Effects of Sea Spray
Atmosphere-Ocean Coupling

3. Surface fluxes and stress
ATMOS. MODEL
(MM5/COAMPS/WRF)
OCEAN MODEL
(HYCOM or 3DUOM)
WAVE MODEL
(WAVEWATCH III or WAM)
Roughness length
Wind-induced stress
Surface fluxes and stress
SST
SSH & current velocity
Wave-Induced stress
Coupled Atmosphere-Wave-Ocean Modeling System for Hurricane Predictions
LES
Sea
Spray
Param. of spectral tail and drag coefficient
Param. of wave dissipation
Source function?
Drop size distribution?
Effects on turbulence?
How do these affect exchange coefficients of enthalphy? What is the ratio of CD and Ch/Cq?

4. Coupled Modeling System
MM5 (PSU/NCAR)
(vortex-following nests with 45, 15, 5, and 1.67 km grid spacing, NCEP analysis and AVHRR or TMI/AMSR-E SST)
WAVEWATCH III (NOAA/EMC)
(1/12o, 25 frequency bands, 48 directional frequency bands)
HYCOM (UMiami/NRL)
(1/12o, 22 vertical levels with 4-6 in the ocean mixed layer)
3DUOM (Price’s 3-D Upper Ocean Circulation Models)

9. Open Ocean (Northeast)
Observed
WW3

10. Landfall (Southwest)
Observed
WW3

11. Wind-Wave Coupling

12. Coupled MM5-WAVEWATCH III
Roughness Length (non-directional)
t = tt + tw zo
zo - wave-age dependent
Stress Vector (directional)
Mx = - tx
My = - ty
tx , ty - components of stress from integral of
momentum input to the wave spectrum. V t

13. Wind-Wave Coupling Spectra Tail Parameterization:
Spectra Tail Parameterization:
X-component of stress from integral of momentum input to the spectrum:
Growth rate of each component from measurement of pressure-slope correlation
Spectrum of long waves from WAVEWATCH III; spectrum of short waves from fit to tail given below. a is adjusted to fit the highest modeled wavenumbers.
b is the spreading function for the short waves.

14. Drag coefficient in high-wind conditions (Donelan et al. 2004)
Figure 4. Vorticity contours obtained via Digital Particle Image Velocimetry (DPIV) in the air flow over wind driven
waves [Reul, 1998]. Both wave and air flow are from left to right. (Top) waves of gentle slope – non-separated flow.
(Bottom) waves of steep slope – separated flow.
Z(cm)
x (cm) 6

19. Hurricane Floyd (1999)

20. Hurricane Floyd (1999)

21. Atmosphere-Ocean Coupling

22. Hurricane Bonnie (1998)

23. Before Bonnie . .
After Bonnie . . . . . . .

25. Hurricane Bonnie (1998)

26. Net Heat Flux
Uncoupled
Coupled Ocean

27. Temperature Profiles
Open Ocean
Gulf Stream

28. CBLAST 2003 Field Program
Hurricane Isabel

33. TRMM TMI

34. NOAA/HRD&AOC Radar Composites in Hurricane Isabel
9/12/ UTC
9/12/ UTC
9/13/ UTC
9/13/ UTC
9/14/ UTC
9/14/ UTC

36. Floyd (1999)
Isabel (2003)

37. Floyd (1999)
Isabel (2003)

39. Coupled Atmosphere-Wave-Ocean Modeling
CBLAST-Hurricane
Coupled Atmosphere-Wave-Ocean Modeling
Conclusions and Future Work
Hurricane intensity and track (to a lesser degree) forecasts are very sensitive air-sea flux parameterizations and wind-wave coupling, especially at very high resolution.
New air-sea coupling parameterizations are needed for high-resolution, coupled atmosphere-wave-ocean models for hurricane prediction.
Coupling parameterizations will be improved and transferred to other coupled modeling systems, e.g. COAMPS (collaboration with Dr. Shouping Wang).