Louisiana State University LSU Digital Commons LSU Doctoral Dissertations Graduate School 2014 Numerical Experiments of Hurricane Impact on Vertical Mixing and De-Stratification of the Louisiana Shelf Waters Mohammadnabi Allahdadi Louisiana State University and Agricultural and Mechanical College, [email protected] Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_dissertations Part of the Oceanography and Atmospheric Sciences and Meteorology Commons Recommended Citation Allahdadi, Mohammadnabi, "Numerical Experiments of Hurricane Impact on Vertical Mixing and De-Stratification of the Louisiana Shelf Waters" (2014). LSU Doctoral Dissertations. 3268. https://digitalcommons.lsu.edu/gradschool_dissertations/3268 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Doctoral Dissertations by an authorized graduate school editor of LSU Digital Commons. For more information, please [email protected]. NUMERICAL EXPERIMENTS OF HURRICANE IMPACT ON VERTICAL MIXING AND DE-STRATIFICATION OF THE LOUISIANA SHELF WATERS A Dissertation Submitted to the Graduate Faculty of the Louisiana State University and Agricultural and Mechanical College in partial fulfillment of the requirements for the degree of Doctor of Philosophy in The Department of Oceanography and Coastal Sciences by Mohammadnabi Allahdadi B.S., Shiraz University, 1998 M.S., University of Tehran, 2001 May 2015 ACKNOWLEDGEMENTS This dissertation would have been incomplete without the dedicated help from numerous people as listed below: First, I would like to express my sincere gratitude to my adviser Dr. Chunyan Li, for his financial support during my studies and his great impact on my study in Oceanography through both courses and group meetings. I’m so much grateful for his patience and scientific comments that highly improved my dissertation. I am also grateful to the other committee members, Drs. Nan Walker, Barry Keim, Nancy Rabalais and Laura Ikuma, for suggestions which improved this dissertation substantially. I would like to thank Dr. Changsheng Chen (University of Massachusetts-Dartmouth) for his kindness in sharing the FVCOM code. I would like to acknowledge the former WAVCIS colleagues Dr. Seyed Mostafa Siadat Mousavi and Dr. Felix Jose and the former CSI Ph.D. student Dr. Clint Edrington for their kind suggestions and help during and after their presence at LSU. Also, I always appreciate and remember the great help and kindness of my former advisor, Dr. Gregory W. Stone (late). Lastly, the seemingly endless patience and support of my wife must also be recognized. ii TABLE OF CONTENTS ACKNOWLEDGEMENTS ............................................................................................................ ii ABSTRACT .....................................................................................................................................v CHAPTER 1: INTRODUCTION AND BACKGROUND INFORMATION ................................1 1.1 Introduction ..........................................................................................................................1 1.2 Background and Literature Review .....................................................................................1 1.3 Objectives ............................................................................................................................7 1.4 Approach ..............................................................................................................................7 1.5 Organization of Dissertation ................................................................................................8 CHAPTER 2: INVESTIGATION OF SEASONAL MIXING ALONG THE LOUISIANA COAST USING HYDRODYNAMICS DATA ........................................................9 2.1 Introduction ..........................................................................................................................9 2.2 Data and Methods ................................................................................................................9 2.3 Results ................................................................................................................................10 2.4 Hydrodynamics and Hypoxia ............................................................................................15 2.5 Summary and Conclusions ................................................................................................16 CHAPTER 3: NUMERICAL SIMULATION OF LOUISIANA SHELF CIRCULATION UNDER HURRICANE KATRINA FORCES ..............................................................................17 3.1 Introduction ........................................................................................................................17 3.2 Background ........................................................................................................................17 3.3 Hurricane Katrina...............................................................................................................19 3.4 The Circulation Model .......................................................................................................20 3.5 Preparation of Input Wind .................................................................................................23 3.6 Current Verification ...........................................................................................................28 3.7 Simulation Results for Case B ...........................................................................................39 3.8 Discussion ..........................................................................................................................51 3.9 Summary and Conclusions ................................................................................................54 CHAPTER 4: HURRICANE INDUCED MIXING AND POST-STORM RE- STRATIFICATION OVER THE LOUISIANA SHELF ..............................................................55 4.1 Introduction ........................................................................................................................55 4.2 Model setup for modeling that resolves temperature and salinity .....................................56 4.3 Verification of model .........................................................................................................59 4.4 Model Results ....................................................................................................................66 4.5 Discussion ..........................................................................................................................93 4.6 Summary and Conclusions ..............................................................................................102 CHAPTER 5: NUMERICAL EXPERIMENT OF STRATIFICATION INDUCED BY SOLAR HEATING OVER THE LOUISIANA SHELF .............................................................104 5.1 Introduction ......................................................................................................................104 5.2 Numerical Model .............................................................................................................104 iii 5.3. Model Specification ........................................................................................................106 5.4 Simulation Results ...........................................................................................................109 5.5 Effect of Diurnal Heating on Bottom Oxygen .................................................................116 5.6 Summary and Conclusion ................................................................................................117 CHAPTER 6: SUMMARY..........................................................................................................118 6.1 Introduction ......................................................................................................................118 6.2 Highlights .........................................................................................................................118 6.3 Suggestion for Future Research .......................................................................................121 REFERENCES ............................................................................................................................123 APPENDIX A: TEMPERATURE VARIATIONS INDUCED BY HURRICANE KATRINA ACROSS THE SELECTED EAST-WEST SECTIONS AT DIFFERENT TIMES AS DESCRIBED IN SECTION 4.4.3 ............................................................................133 APPENDIX B: TEMPERATURE VARIATIONS INDUCED BY HURRICANE KATRINA ACROSS THE SELECTED NORTH-SOUTH CROSS-SECTIONS AT DIFFERENT TIMES AS DESCRIBED IN SECTION 4.4.3......................................................147 APPENDIX C: SOME MODELING RESULTS FOR FALL STORMS ...................................163 APPENDIX D: FORMULATION OF DIFFERENT SURFACE HEAT COMPONENTS .......169 APPENDIX E: COVER PAGE OF JOURNAL OF COASTAL RESEARCH PAPER .............171 APPENDIX F: LETTER OF PERMISSION; JOURNAL OF COASTAL RESEARCH ...........172 VITA……………………………………………………………………………………….. ......173 iv ABSTRACT The numerical model FVCOM (Finite Volume Community Ocean Model) was applied to study the effects of Hurricane Katrina on the vertical mixing over the Louisiana shelf and the process of post-storm re-stratification. Wind field from Hurricane Katrina was