The Hurricane’s Inner Core Region. II. Thermal Stability and Dynamic Characteristics

Abstract

This is the second (Paper II) of two papers on the characteristics of the hurricane?s inner core region as revealed by the research flight data of the National Hurricane Research Laboratory. This paper presents information on the thermal stability and the dynamic characteristics of the hurricane?s inner core region from information derived from Paper I. Discussion is given on the hurricane?s inner core vertical stability, divergence, vertical motion, heating mechanism, wind-pressure acceleration, thermal wind balances, and other features. It is shown that large vertical moist instability is present in the eye-wall cloud. Large super-gradient winds are present at the radius of maximum winds. Substantial mixing occurs between eye and eye wall and the average hurricane eye ventilates itself by about half of its mass during the time it takes to move the distance of its eye diameter. Maximum heating does not occur at the radius of maximum updraft. Inner core heating comes from the sinking motion within the eye and not from heat diffusion from the cumulus updraft. Other features are discussed.