Project Title and Principal Investigator(s)

1. Tropical Cyclone Structure-2008 (TCS-08)ONR/NRL Funded Projects Background Project Title and Principal Investigator(s) Scientific Objectives Field Experiment Requirements • Tropical cyclogenesis and subsequent structure change are multiscale processes that challenge current theoretical understanding and numerical weather prediction capabiities • Several theories on the relative importance of convective and stratiform regions in tropical cyclogenesis have been proposed, but theoretical and numerical model predictions require further scrutiny • New observations are needed to test our new TC genesis and secondary eyewall formation hypotheses; necessary for understanding limits of predictability A Multiscale Study of Tropical Cyclone Formation, Structure Change and Predictability in the Western North Pacific Region Michael T. Montgomery (mtmontgo@nps.edu) Michael M. Bell (mmbell@nps.edu) Naval Postgraduate School Monterey, CA 93943 • Test new “marsupial” theory of TC formation emphasizing importance of sub-synoptic scale “pouch” and dominance of sustained deep convective (e.g. VHT) processes within the pouch during West-Pac TC formation • Collect data, analyze and interpret mesoscale and cloud-scale processes within the “pouch” during TC formation using in-flight, dropsonde and Doppler radar observations. Perform companion high res. cloud resolving simulations • Observe TC outer-wind structure, including secondary eyewall development and compare against our new hypothesis and high res. simulations • Execute flight modules designed to evaluate the contribution of both mesoscale and cloud scale processes in the amplification of the low-level cyclonic circulation during TC genesis and secondary eyewall formation • Obtain three-dimensional observations by the NRL P-3 and AF-C130 using ELDORA, Doppler wind lidar, dropsondes, and flight level data, of the deep convective and stratiform regions in developing TCs, and the outer wind structure of mature TCs