The CBLAST-Hurricane Program and the Next-Generation Fully Coupled Atmosphere–Wave–Ocean Models for Hurricane Research and Prediction

Abstract

sphere-wave-ocean modeling system that is capable of resolving the eye and eyewall at ~1-km grid resolution, which is consistent with a key recommendation for the next-generation hurricane-prediction models by the NOAA Science Advisor Board Hurricane Intensity Research Working Group.It is also the National Centers for Environmental Prediction (NCEP) plan for the new Hurricane Weather Research and Forecasting (HWRF) model to be implemented operationally in 2007-08. AIR-SEA INTERACTION AND HURRI-CANES.Hurricanes rarely reach their maximum potential intensity (MPI, as defi ned by Kerry Emanuel and Greg Holland).Many factors can prevent a given storm from reaching MPI, including environmental vertical wind shear, distribution of troposphere water vapor, hurricane internal dynamics, and air-sea interactions.Th e eff ect of air-sea interactions on hurricane structure and intensity change is the main focus of the CBLAST-Hurricane program.Intensifi cation of a hurricane depends upon two competing processes at the air-sea interface-the heat and moisture fl uxes that fuel the storm and the dissipation of kinetic energy associated with wind stress on the ocean surface.Air-sea interaction is especially important within the extremely high winds (up to 75 m s -1 ) and strong gradient zones of temperature and pressure located in the inner core (eye and eyewall) of a hurricane.Th e enthalpy and momentum exchange coeffi cients under the extreme high-wind conditions are, of course, very diffi cult to determine in precisely the regions where they are most important.Th e stress is supported mainly by waves in the wavelength range of 0.1-10 m, which are an unresolved "spectral tail" in present wave models.In the November 1995 Journal of the Atmospheric Sciences, Emanuel proposed that storm intensity is largely controlled by the ratio of the air-sea enthalpy