The Large-Scale Inflow-Layer Structure of Hurricane Frederic (1979)

Abstract

Abstract Aircraft, rawinsonde, satellite, ship, and buoy data collected over a 40-h period were composited to analyze the inflow-layer structure of Hurricane Frederic (1979) within a radius of 10° latitude of the storm center. To improve the quality of the composite analyses, the low-level cloud-motion winds (CMWs) employed in this study were assigned a level of best fit (LBF). An LBF was assigned to each CMW by determining the level at which the closest agreement existed between CMW and ground-truth wind data (e.g., rawinsonde, aircraft, ship, and buoy). The CMWs were then adjusted vertically to uniform analysis levels, combined with ground-truth wind data, and objectively analyzed. These objectively analyzed wind fields were used to obtain kinematically derived fields of vorticity, divergence, and vertical velocity. An angular-momentum budget was also computed to obtain estimates of surface drag coefficients. The low-level CMWs in this study were found to have LBFs ranging from 300 to 4000 m. It was sho...