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Dual-Polarimetric Radar Characteristics of Convective-Wind DUAL-POLARIMETRIC RADAR CHARACTERISTICS OF CONVECTIVE-WIND-PRODUCING THUNDERSTORMS OVER KENNEDY SPACE CENTER by Cort A. Scholten B.S., Central Michigan University, 2010 THESIS Submitted to Plymouth State University in Partial Fulfillment of the Requirements for the Degree of Master of Science in Applied Meteorology December 2013 This thesis has been examined and approved. ___________________________________________ Thesis Director, Dr. James P. Koermer Professor Emeritus, Meteorology Department of Atmospheric Science and Chemistry ___________________________________________ William P. Roeder Meteorologist, Systems Staff Meteorology 45th Weather Squadron, Patrick Air Force Base, FL ___________________________________________ Dr. Samuel T.K. Miller Associate Professor of Meteorology Department of Atmospheric Science and Chemistry ________________________________ Date DEDICATION This thesis is dedicated to my parents, Thomas and Sally Scholten, for their immeasurable love and sacrifice. I also want to recognize my grandparents, aunts, uncles, brothers, cousins, professors, teachers, colleagues, and friends for supporting and encouraging me throughout my academic journey. iii ACKNOWLEDGMENTS This project was funded by the New Hampshire Space Grant Consortium, in cooperation with the Judd Greg Meteorological Institute and Plymouth State University. The NASA Higher Education Office, Applied Meteorology Unit (ENSCO, Inc.), and the Air Force 45th Weather Squadron in Cape Canaveral, Florida, provided a venue, technological & intellectual support, and a welcoming atmosphere during the summer of 2012. My thesis committee – Dr. James P. Koermer, Mr. William P. Roeder, and Dr. Samuel T. K. Miller – deserve an enormous amount of gratitude for their constructive comments, endless patience, and attitudes that show they really love their careers in meteorology and helping students succeed. iv TABLE OF CONTENTS DEDICATION ....................................................................................................... iii ACKNOWLEDGMENTS ...................................................................................... iv TABLE OF CONTENTS ....................................................................................... v LIST OF TABLES .............................................................................................. viii LIST OF FIGURES ............................................................................................... ix ABSTRACT ........................................................................................................ xiii CHAPTER 1 ......................................................................................................... 1 1. Introduction .................................................................................................... 1 a. Overview ................................................................................................. 1 b. Background ............................................................................................ 4 1) PREVIOUS RESEARCH .................................................................... 4 (i) Microburst knowledge ..................................................... 4 (ii) KSC/CCAFS convection climatology ........................... 13 (iii) KSC/CCAFS radar studies .......................................... 14 2) DUAL-POLARIMETRIC RADAR ........................................................ 15 (i) Overview ....................................................................... 15 (ii) Products ....................................................................... 17 (iii) Meteorological features ............................................... 23 CHAPTER 2 ....................................................................................................... 27 2. Data and Methods ........................................................................................ 27 a. Data ...................................................................................................... 27 v b. Methods ................................................................................................ 29 CHAPTER 3 ....................................................................................................... 33 3. Results.......................................................................................................... 33 a. KDP column height ................................................................................. 35 b. KDP column intensity ............................................................................. 41 c. ZDR column height ................................................................................. 42 d. 50 dBZ height ....................................................................................... 44 CHAPTER 4 ....................................................................................................... 46 4. Discussion ................................................................................................... 46 a. Comparison to Harris (2011) ................................................................ 46 b. Additional Florida findings ..................................................................... 50 c. Challenges ............................................................................................ 55 1) PHYSICAL AND ENVIRONMENTAL ................................................... 56 2) OBSERVATION ............................................................................ 60 3) VISUALIZATION AND INTERROGATION ............................................. 66 CHAPTER 5 ....................................................................................................... 68 5. Conclusions ................................................................................................. 68 APPENDIX A ...................................................................................................... 73 G2Analyst Display Settings ............................................................................. 73 a. Color tables .......................................................................................... 73 1) REFLECTIVITY ............................................................................. 74 2) DIFFERENTIAL REFLECTIVITY ........................................................ 74 3) CORRELATION COEFFICIENT ......................................................... 75 vi 4) DIFFERENTIAL PHASE .................................................................. 75 5) SPECIFIC DIFFERENTIAL PHASE ..................................................... 76 b. Background image ................................................................................ 76 c. Smoothing ............................................................................................. 78 1) BENEFITS AND DRAWBACKS ......................................................... 78 2) GR2ANALYST SMOOTHING OPTIONS ............................................. 81 APPENDIX B ...................................................................................................... 83 Tabular Data and Plots for Each Case ............................................................ 83 REFERENCES ................................................................................................. 104 vii LIST OF TABLES Table 1. 45 WS convective wind gust warning requirements, from Loconto (2006). The 60 kt criterion was discontinued since Loconto (2006). Patrick AFB requirements not shown but include other requirements related to convective winds such as gust spread and low-level wind shear....................................................................................................... 3 viii LIST OF FIGURES Figure 1. Annual mean cloud-to-ground lightning flash density for the contiguous United States, 1997-2007 (Vaisala 2013). The greater flash density located in the southeastern United States is at a maximum in central Florida, which earns it the nickname “Lightning Alley.” .......................... 2 Figure 2. Representative soundings for dry, hybrid, and wet microburst environments (Ellrod 1989). .................................................................. 7 Figure 3. Annual frequency any convective wind gust within an 80 km grid square, based on data for the period 1980-1994 (Doswell and Bosart 2001). .................................................................................................... 8 Figure 4. Locations of KSC/CCAFS wind towers, KTIX, KTTS, and KXMR. Data from the black numeric identifiers were used in Koermer and Roeder (2008). The inset map with a red star shows where in Florida KSC/CCAFS is located (from Harris 2011). ......................................... 14 Figure 5. A basic comparison of conventional versus dual-polarized radar. The red and blue waves represent horizontal and vertical pulses, respectively (Radar Operations Center, cited 2012). ........................... 16 Figure 6. Typical values of ZDR for meteorological and non-meteorological targets (Warning Decision Training Branch 2013). .......................................... 18 Figure 7. Typical values of ρHV for meteorological and non-meteorological targets (Warning Decision Training Branch 2013). .......................................... 20 Figure 8. Example of the relationship between Z, ΦDP, and KDP. Images obtained from the Vance Air Force Base WSR-88D (KVNX; located at the red dot in the lower-right of each image) at 0018 UTC, 01 May 2012. ...........
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