3 Jun 2025

Wind Forcing, Source Term and Grid Optimization for Hurricane Wave Modelling in the Gulf of Mexico

Abstract: This study evaluates the performance of WAVEWATCH III model driven by different wind forcing products and behavior of different parameterizations of the model’s source terms controlling energy input and dissipation and quadruplet wave-wave interactions during Hurricane Ida. We also compare the performance of the model configured on uniform unstructured and conventional non-uniform unstructured grids. Key findings show ECMWF-forecast and HRRR out-performed other products in capturing wind speeds relative to buoys, satellite and the revised Atlantic hurricane database observations. However, all products underestimated wind speeds above 20 m/s, with ECMWF and HRRR occasionally performing better for most wind speed values above 35 m/s relative to observations. The corresponding wave simulation results indicated Ida’s wave fields were better captured by model simulations with ECMWF and HRRR wind products, with biases of 2% against buoys in the Gulf of Mexico and 6% and 3% respectively against satellite data. We also highlighted limitations in bulk wave analysis by computing partial Hs and 1D spectra density differences between model and buoy for selected source terms. This reveals consistent overestimation at the lowest frequency bin and underestimation of the three higher frequency bins with a mix of negative and positive energy density difference across different frequencies.

29 Jul 2022

Sediment Provenance Studies of the Calcasieu Ship Channel, Louisiana

Abstract: To maintain the navigability of the Calcasieu Ship Channel (CSC), the US Army Corps of Engineers annually dredges millions of cubic yards of sediment from the inland channel. To assess sources of channel shoaling, a previous study examined river and bankline erosion as inputs. Results from that study accounted for approximately 20% of dredged volumes. Through the support of the Regional Sediment Management Program, a follow-up investigation reviewed prior sediment budgets, identified potential missing sediment sources, modeled potential sediment pathways, and utilized geochemical fingerprinting to discern primary shoaling sources to the channel. The missing sediment sources from the original budget include coastally derived sediment from the Gulf of Mexico and terrestrially derived sediment from Lake Calcasieu and surrounding wetlands. Results from geochemical fingerprinting of various potential sediment sources indicate the Calcasieu River and the Gulf of Mexico are primary contributors of sediment to the CSC, and sediments sourced from bankline erosion, Lake Calcasieu bed, and interior wetlands are secondary in nature. These results suggest that engineering solutions to control shoaling in the CSC should be focused on sources originating from the Gulf of Mexico and river headwaters as opposed to Lake Calcasieu, channel banklines, and surrounding wetlands