An observatinal and numerical study of the boundary layer processes during the intensification of Hurricane Bill (2009)

The atmospheric boundary layer plays a key role in the distribution of atmospheric moisture and angular momentum that regulate the hurricane intensity change. In order to analyze different mechanisms which control the boundary layer processes related to hurricane intensification, we have simulated Hurricane Bill (2009) by means of the experimental version of Hurricane Weather and Forecasting (HWRF-X) model that is being developed at the Hurricane Research Division (HRD), and compared model simulations to observational data collected by NOAA's P3 aircraft. Ensemble based sensitivity analysis of the modelled boundary layer processes during the intensification period of Hurricane Bill is carried out. Direct and continuous measurements of the boundary layer structure by the GPS dropsondes and Doppler radar are used to evaluate the results obtained by the model.