Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2003 Hurricane Surface Wind Model for Risk Management Lizabeth Marie Axe Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] THE FLORIDA STATE UNIVERSITY COLLEGE OF ARTS AND SCIENCES HURRICANE SURFACE WIND MODEL FOR RISK MANAGEMENT By LIZABETH MARIE AXE A Thesis submitted to the Department of Meteorology in partial fulfillment of the requirements for the degree of Masters of Science Degree Awarded: Fall Semester, 2003 The members of the committee approve the thesis of Lizabeth Marie Axe defended on September 23, 2003. ____________________________________ T. N. Krishnamurti Professor Directing Thesis ____________________________________ Paul H. Ruscher Committee Member ____________________________________ Philip Cunningham Committee Member ____________________________________ Steven Cocke Committee Member The Office of Graduate Studies has verified and approved the above named committee members. ii To my parents whose enduring and insurmountable love, encouragement, and support made this study and my entire academic career possible. iii ACKNOWLEDGEMENTS First and foremost, I would like to thank God, for I am nothing without him. I give many thanks and appreciation to my major professor, Dr. T. N. Krishnamurti, for all of his support and encouragement. I would also like to thank my committee members, Dr. Paul H. Ruscher and Dr. Philip Cuningham, for their comments and suggestions. Thank you to everyone in the Dr. Krishnamurti’s lab for their assistance and advice, especially Dr. Steve Cocke for patience and the know-how, Brian Mackey for his never-ending help and advice, and Andy Schwartz for keeping the experience real. Finally, I give many thanks to my family and friends for their never-ending encouragement during my entire academic career. iv TABLE OF CONTENTS LIST OF TABLES .....................................................................................................................vii LIST OF FIGURES ...................................................................................................................viii ABSTRACT................................................................................................................................xi 1 INTRODUCTION................................................................................................................1 1.1 Overview....................................................................................................................1 1.2 Objectives and Organization of Thesis ......................................................................3 2 WIND COMPONENT.........................................................................................................5 2.1 Synthetic Vortex Profile.............................................................................................5 2.1.1 Rankine Vortex Equations ...................................................................................5 2.1.2 Model Parameters ................................................................................................8 2.1.3 Model Example....................................................................................................8 2.2 Reduction of Flight Level Winds to the Surface Layer .............................................10 2.2.1 GPS Dropwindsonde Measurements ...................................................................10 2.2.2 Adjustment Function to the 300 m Level ............................................................13 2.3 Wind Reduction From the Top of the Surface Layer to 10 m...................................14 3 ROUGHNESS COMPONENT...........................................................................................16 3.1 Introduction to Surface Roughness............................................................................16 3.2 Roughness Data Set ...................................................................................................16 3.2.1 Estimation of Surface Roughness by HAZUS .....................................................17 3.2.2 Land-Use/Land-Cover Sources............................................................................18 3.2.3 Conversion From LULC Classes to Roughness Length......................................18 3.3 Effective Roughness ..................................................................................................19 3.4 The Source Area Model.............................................................................................23 3.5 Radial Weight Function.............................................................................................28 3.5.1 Derivation.............................................................................................................29 3.5.2 Sensitivity to the Parameters................................................................................30 3.6 Azimuthal Dependence..............................................................................................32 3.7 Examples....................................................................................................................33 4 RESULTS .............................................................................................................................40 4.1 Comparison of Local vs. Effective Roughness..........................................................40 v 4.2 Sensitivity to Model Parameters ................................................................................44 4.3 Real World Examples ................................................................................................49 4.3.1 Hurricane Andrew Case Study.............................................................................49 4.3.2 Hurricane Erin Case Study...................................................................................52 4.3.3 Hurricane Kate Case Study..................................................................................54 4.3.4 Hurricane Donna Case Study...............................................................................56 4.4 Historical Hurricane Scenarios ..................................................................................58 4.4.1 Estimations of Unknown Parameters...................................................................59 4.4.2 1852 Hurricane Case Study..................................................................................60 5 CONCLUSIONS ..................................................................................................................62 5.1 Discussion and Summary...........................................................................................62 5.2 Future Work ...............................................................................................................64 REFERENCES...........................................................................................................................65 BIOGRAPHICAL SKETCH....................................................................................................68 vi LIST OF TABLES 1 Roughness lengths of homogeneous surface types (Wieringa 1993) ....................................17 2 FLUCCS Level 1 Classifications ...........................................................................................18 3 Example of the FLUCCS Level 2 Classification Using the Urban and Built-Up and Agricultural............................................................................................................................19 4 Normalized Set of Isopleth Dimensions Relative to the 0.5 Isopleth using the Statistical Source Area Model (Schmid 1990) .......................................................................................27 vii LIST OF FIGURES 1 The wind model rankine-like vortex. The thick line represents the upper-level winds, and the thin line represents the 10 m winds..........................................................................7 2 Model output of flight level winds for hurricane Andrew at the time landfall.....................9 3 Mean hurricane wind speed profiles for the eyewall and outer-vortex regions. Wind speeds are averaged and expressed as a fraction of the profile wind speed profile at 700 mb. The minimum number of profiles used to construct the averages is indicated (Franklin 2003). ....................................................................................................................11 4 Mean wind speed profiles for eyewall sondes released within 5.6 km (3 n mi.) of the flight level Rmax (RMW), for eyewall sondes released at least 7.4 km (4 n mi.) radially outward of the Rmax, and for eyewall sondes released at least 7.4 km radially inward of the Rmax. All winds are averaged and express as a percentage of the profile 700 mb wind speed (Franklin 2003). ..........................................................................................................12 5 Same as in Figure 3, but with the height plotted on a logarithmic scale (Franklin 2003)....13 6 HAZUS Roughness Lengths for the State of Florida in meters. ..........................................20 7 The source area in one-dimensional patchiness determined by the distances at which an IMIF and EIF reach the sensor height (zs) (Schmid 1990). ..................................................23 8 Schematic cross-section of a P source area (Schmid 1990) .................................................24