Grant: $751,041 - National Science Foundation - Aug. 26, 2009
50% voted satisfied - 50% voted not satisfied - 4 vote(s) cast
Award Description: Understanding the hurricane boundary layer processes is of vital importance, not only to scientific study of hurricane genesis, development, and dissipation during landfall, but also to effective promotion of hurricane mitigation measures. Despite ever increasing observational network and model sophistication, there is still a gap in our knowledge of hurricane boundary layer processes, and a realistic representation of their effects in numerical forecasting models continues to be a challenge. This project is designed (1) to advance our understanding of the hurricane boundary layer processes, their up-scale impact on hurricane development, and their down-scale bearing on coastal damage, (2) to improve the parameterization of sub-scale hurricane boundary layer processes in numerical models, and (3) to develop novel approaches to depict and predict the hurricane boundary layer wind fields at landfall for various applications in hurricane damage mitigation. To fulfill the goal, a distinct multiple scale modeling system from the Weather Research & Forecasting (WRF) model, which features a large eddy simulation (LES) in a weather forecasting/hindcasting mode, will be developed. The WRF-LES not only allows for explicit simulations across a spectrum of scales from the large-scale background flow, hurricane vortex, deep convection, meso-vortices, down to turbulent eddies in a unified system, but also provides a new framework to fully exploit the available observations. The combined multiple scale simulations and observational analyses will be used to address key issues regarding the vertical transport in the hurricane boundary layer and the turbulent processes and surface wind structures at landfall. The proposed investigation will improve the parameterization of hurricane boundary layer processes in numerical models. Such an effort will lead to a more accurate prediction of hurricane intensity. The proposed study of hurricane boundary layer turbulence and wind structure at landfall will play a critical role in hurricane preparedness and mitigation. The proposed modeling system can be upgraded into an operational mode with sufficient computational power for commercial hurricane risk/damage assessment and prediction. The education and outreach of this project will develop basic scientific awareness of model uncertainty in the prediction of hurricane track and intensity and the human impact of hurricanes through boundary layer processes and to increase critical thinking skills focusing on hurricane research, prediction, its interaction with climate change for graduate, undergraduate, and K-12 students. This project will provide great research opportunities for students majoring in atmospheric sciences, environmental sciences, computing and information sciences, and civil and environmental engineering at FIU. New courses related to hurricanes and their human and economic impacts will be developed at graduate and undergraduate levels. The local educational outreach activities and initiatives will help to build an interactive relationship between faculties, scientists, students, and the local community.
Project Description: This is a five-year project. We just started a month ago. Below are the activities and research results of this month. 1. We have started process to recruit two graduate students for the next Fall. 2. We are planning to build a new Linux cluster and update the tower. Currently we are seeking quotes from different companies. 3. We analyzed wind tower data collected during the major landfalling hurricanes in 2002-2004 season using wavelet transform (WT). The T, which decomposes a time series onto the frequency-time domain, provides means to investigate the role of turbulent eddies with different scales n vertical transport in the unsteady, inhomogeneous hurricane boundary layer (HBL). It is found that the contribution from large eddies to the total turbulent fluxes and turbulent kinetic energy (TKE) decreases as approaching the storm center where turbulence associated with eyewall and rainbands is intense. On the other hand, the relative importance of smaller size eddies, which are enhanced possibly through eddy breaking due to the strong turbulence, increases near the storm center, causing the peak of energy spectrum to shift toward high frequency. This result illustrates the unique characteristics of the HBL turbulent transport processes, which may not be appropriately represented by the existing turbulent schemes developed under the non-hurricane environment. This work has completed, and we are currently writing a paper, which will be submitted to JAS.
Jobs Summary: 00 (Total jobs reported: 0)
Project Status: Less Than 50% Completed
This award's data was last updated on Aug. 26, 2009. Help expand these official descriptions using the wiki below.