Date of Award
2020
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Atmospheric Science
Committee Chair
Udaysankar Nair
Committee Member
Larry D. Carey
Committee Member
John R. Mecikalski
Committee Member
Arastoo Biazar
Committee Member
Pawan Gupta
Subject(s)
Wind forecasting, Weather forecasting, Tehuantepec, Gulf of (Mexico)
Abstract
Mountain Gap Winds (MGW) are low-level jets forced by gaps along elongated complex terrain that act as flow barriers. A prominent occurrence of MGW, forced by the Chivela pass in southern Mexico, is found over the Gulf of Tehuantepec in the eastern Pacific where it impacts air, marine transport, fisheries, and tropical cyclogenesis. Though this MGW was subject of numerous studies, crucial aspects yet to be addressed include improving the forecasting of this phenomenon and understanding the impact of MGW on the evolution of tropical cyclones in the East Pacific. Computationally inexpensive linear regression model (LRM) and Recurrent Neural Network (RNN) can be used to improve MGW forecasts from coarse resolution numerical models. Weather Research and Forecast (WRF) model forecasts can be improved by adequately resolving flow through the mountain gap and by using dynamic ocean-atmosphere coupling. Performance of LRM and RNN are comparable to such WRF forecasts. WRF simulations show the presence of MGW in the eastern Pacific can intensify tropical cyclones and enhance rainfall. Unique contributions of this study include: 1) new methods for MGW forecasting, 2) a better understanding of MGW dynamics contributing to improvements in numerical prediction, and 3) first numerical modeling investigation of MGW impacts on tropical cyclones.
Recommended Citation
Foshee, Emily, "Mesoamerican mountain gap winds : forecasting and understanding the impact on regional weather" (2020). Dissertations. 259.
https://louis.uah.edu/uah-dissertations/259