On the important role of aircraft observations in hurricane model physics improvement

As part of the NOAA's Hurricane Improvement and Forecast Project (HFIP), this talk addresses the fundamental importance of aircraft observations for hurricane model development. We present a diagram of improving the hurricane model physics using aircraft observations through processes that include model diagnostics, physics development, physics implementation and further evaluation. Model deficiency is firstly identified through model diagnostics by comparing simulated and observed hurricane structures. New physical parameterization is then developed based on observational data obtained during specially-designed hurricane field programs. The new physics package is then implemented into the model by model developers in collaboration with observation scientists, which is followed by further evaluation against observations. The above processes are found to be successful for improving the surface layer and boundary layer parameterization schemes in the operational Hurricane Weather Research and Forecast (HWRF) model. We also discuss the requirements for good quality observations for hurricane model development as well as challenges for obtaining such observations.