Tropical Cyclone Surface Pressure Retrieval From Ocean Vector Wind Sensors

Throughout most of the ocean basins where tropical cyclones (TCs) are found, satellite remote sensing is the dominant source of observations. Dvorak techniques have proven to be a valuable means for estimating TC intensity. While not a replacement for the Dvorak method, we have been developing means by which the surface pressure drop can be estimated from satellite ocean vector wind data acquired from scatterometers or synthetic aperture radar (SAR). The pressure drop is obtained from surface pressure patterns derived from the ocean vector wind data using a TC-specific diagnostic atmospheric boundary layer (ABL) model. The ABL model includes dynamical shallowing of the TC toward the center of the swirling flow, and storm-motion-relative nonlinear mean flow curvature effects. Either of these remote sensors has strengths and weaknesses. Scatterometer data are plentiful and freely available, but are produced at coarser spatial resolution (~12.5 to 25 km wind vector cells). SAR data has much higher spatial resolution (~1 km wind vector cells), but is relatively more expensive and acquisitions much be planned in advance. We will present the methodology and comparisons with in situ aircraft and drop sonde data.