Discipline: Technology and Engineering
Subcategory: Environmental Engineering
Kyra M. Bryant - Tennessee State University
Co-Author(s): Simbarashe Kanjanda and Muhammad Akbar, Tennessee State University, Nashville, TN
As increasing sea surface temperatures pave the way for more powerful hurricanes [1][5] and population growth remains unwavered in low-elevation coastal zones [6], the time is certainly ripe for accurate hurricane storm surge prediction. Emergency management officials need a reliable model to properly minimize loss of life, which also benefits authorities in preventing and limiting risks when designing coastal structure protection. A reliable model accurately portrays each parameter associated with hurricane storm surge. This study examines the significance of wind stress, bottom friction, surface roughness, and meteorological forcing used in the ADVanced CIRCulation (ADCIRC) hydrodynamic model [7] and the Simulating WAves Nearshore spectral wave model coupled with ADCIRC (SWAN+ADCIRC) [8]. If each of these components carry weight in calculating storm surge, then these parameters must be carefully defined in a forecasting model. To test this assumption, different wind stress drag coefficients, Manning’s n bottom friction values, surface roughness lengths, and meteorological forcing formats were evaluated in ADCIRC and SWAN+ADCIRC using Hurricane Rita (2005) hindcasts. Each result’s validity was tested by comparing the outcome against available observational data. This data consisted of water surface elevations recorded as Hurricane Rita made landfall in the Gulf of Mexico at eight United States Geological Survey (USGS) stations in the vicinity. The results were also compared with other published results. The comparisons revealed which parameters held the most weight and which meteorological forcing options were most accurate in predicting storm surge. Lower wind stress drag coefficients produced results closest to accuracy. Increased bottom friction reduced the water surface elevations, which were previously over predicted. Adjusting the surface roughness yielded no significant improvements. Of the five meteorological formats explored, only the Ocean Weather Inc. (OWI) Interactive Object Kinematic Analysis (IOKA) Model proved its ability to capture the asymmetric structure of a hurricane. Of the five components investigated, four showed distinct relevance in the models. Following the discovery of which parameters are capable of offering more accuracy, future individual investigations of wind stress and bottom friction are anticipated. This will require more testing with various hurricanes. The final accomplishment consists of parameter recommendations for ADCIRC and SWAN+ADCIRC. Once they have been tested and validated, results will be published. Since hurricanes cannot be tamed, a more accurate and efficient model is the only path to avoiding their destruction.
Funder Acknowledgement(s): This study was supported by an HBCU-UP Research Initiative Award (HRD-1401062) granted from the National Science Foundation to Muhammad Akbar, Assistant Professor, Tennessee State University.
Faculty Advisor: Muhammad Akbar, makbar@tnstate.edu
Role: In this study, I thoroughly researched the wind stress component of the experiment and am a co-researcher for the other components. I will be the sole creator of the presentation. I will be a co-author of the paper to be submitted for publication.