AN INVESTIGATION INTO THE CONTAMINATION OF WSR-88D VAD WIND PROFILE OUTPUT BY MIGRATING BIRDS A Thesis by KARL WERNER SCHULZE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 2003 Major Subject: Meteorology AN INVESTIGATION INTO THE CONTAMINATION OF WSR-88D VAD WIND PROFILE OUTPUT BY MIGRATING BIRDS A Thesis by KARL WERNER SCHULZE Submitted to Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Approved as to style and content by: ___________________________ ___________________________ John W. Nielsen-Gammon Richard E. Orville (Chair of Committee) (Member) ___________________________ ___________________________ Keith A. Arnold Gerald R. North (Member) (Head of Department) August 2003 Major Subject: Meteorology iii ABSTRACT An Investigation into the Contamination of WSR-88D VAD Wind Profile Output by Migrating Birds. (August 2003) Karl Werner Schulze, B.S., Northern Illinois University Chair of Advisory Committee: Dr. John W. Nielsen-Gammon The VAD Wind Profile (VWP), a time-height display of winds computed by the National Weather Service’s WSR-88D radar, is known on occasion to have errors at night during the fall and spring seasons. Several studies, such Haro and Gauthreaux (1997), confirm that migrating birds often contaminate the VWP output. By means of telescopic observations of a full moon, birds were observed flying on two nights when VWP contamination was suspected. The nature of the VWP errors is consistent with migrating birds due to the seasonality, nocturnal nature, and the magnitude of the errors found (greater than 10 knots). With careful selection of data, two clusters of points on the Velocity-Azimuth Display (VAD) are found to exist at certain altitudes when birds begin migrating. One cluster of points is due to radar sample volumes containing birds, and the other cluster is from radar sample volumes without birds. Being able to determine which cluster represents the wind could allow the wind to be calculated by the VWP. Present limitations with the Radar Product Generator’s processor and memory prohibit a very advanced detection algorithm. Two simple objective techniques to determine the existence of the two clusters, and determine the wind, were tested. While iv they show some promise, these methods require further operational testing to determine their usefulness for real-time warning of bird contamination and the reporting of the true wind. v DEDICATION I wish to dedicate this thesis to several very important people who have made it all possible in one way or another. First of all, I wish to dedicate this thesis to my parents, Werner and Mary Schulze. Their many years of unconditional support, understanding, and love have given me the freedom and ability to pursue my dreams, even though I tended to stray way off course occasionally. Thanks for the love and support, Mom and Dad! I also wish to dedicate this thesis to Jeanne Lambrecht. Her ability to succeed and her ability to love others, despite many obstacles, make her my role model. Her years of continued love and support have helped me to stay afloat during the tough times I have encountered. Despite our divorce, I am thankful that we have remained best friends. Thanks, Jeanne! Last, but certainly not least, I wish to thank my fiancée - Larisa Timofeyeva! Without the hope and promise of starting things anew, it would have been more difficult to finally complete this thesis. My strong wish to be with her was the motivation to finally kick things into high gear, and she was the bright and beautiful light at the end of the tunnel. I love you very much, Larisa! vi ACKNOWLEDGEMENTS I would like to express my deep gratitude to my advisor, Dr. John W. Nielsen- Gammon. His support and understanding during the difficult times I faced allowed me to finish this thesis. His knowledge and expertise proved very useful as I worked on this thesis. I appreciate very much all your time and effort, John! I also thank my other committee members, Dr. Keith A. Arnold and Dr. Richard E. Orville for their insight and assistance during the completion of this thesis. My thanks also go out to Dr. Michael I. Biggerstaff, who was on my committee before his departure to the University of Oklahoma. His radar knowledge and assistance was very valuable to me. In my many years here at Texas A&M, I have come to know many fellow students with whom I have developed friendships. They are too numerous to mention; you know who you are. Their companionship both inside and outside the weather classroom has been a treasure, and I look forward to continuing my friendship with them in the years to come. In particular, I would like to thank Brandon Ely for his assistance with the IDL programming language, and Scott Steiger for his assistance with WATADS. Finally, thanks go out to Paul Sirvatka for helping me get my foot in the door at the College of DuPage! Both he and his wife Cathy have provided me with a lot of support and encouragement to finish this thesis, and I thank them very, very much! vii TABLE OF CONTENTS Page ABSTRACT................................................................................................................. iii DEDICATION ............................................................................................................. v ACKNOWLEDGEMENTS ......................................................................................... vi TABLE OF CONTENTS............................................................................................. vii LIST OF FIGURES...................................................................................................... ix LIST OF TABLES ....................................................................................................... xv CHAPTER I INTRODUCTION......................................................................................... 1 II PROBLEM.................................................................................................... 6 1. Proving Birds Are the Source of Anomalous VWP Winds ............ 7 2. Case Studies .................................................................................... 14 a. August 19-20, 1997................................................................ 14 b. September, 16-17, 1997......................................................... 33 III LITERATURE REVIEW.............................................................................. 51 1. Migration and Nocturnal Migration ................................................ 51 2. Migration and Meteorology ............................................................ 56 a. Wind and Wind Direction...................................................... 57 b. Precipitation........................................................................... 58 c. Clouds .................................................................................... 60 d. Stability.................................................................................. 63 e. Other Factors.......................................................................... 63 3. Radar Ornithology........................................................................... 64 4. VAD and VWP................................................................................ 70 5. Bird Contamination of the VWP Product ....................................... 74 6. Application to Observations Made in Chapter II ............................ 78 viii CHAPTER Page IV SOLUTION................................................................................................... 81 1. Double VAD Curve Hypothesis...................................................... 82 2. Data ................................................................................................. 85 3. Results ............................................................................................. 87 a. August 15-16, 2000................................................................ 87 b. September 4-5, 2000.............................................................. 112 c. September 5-6, 2000 .............................................................. 132 d. September 6-7, 2000.............................................................. 144 4. Attempted Remedies ....................................................................... 154 a. Curve Isolation Technique..................................................... 156 b. Minimum Variance Technique.............................................. 160 V CONCLUSIONS........................................................................................... 167 REFERENCES............................................................................................................. 173 VITA ............................................................................................................................ 177 ix LIST OF FIGURES FIGURE Page 1 Example of the VAD Wind Profile output from the WSR-88D at Lincoln, Illinois on April 15, 2002 at 3:15Z................................................................ 2 2 Diagram of Lowery's moon-watching technique .......................................... 9 3 (a) Illustration that the area of observation is not the simple ratio to the larger area sought. (b) Reason why simply converting the sample area to the total area fails .......................................................................................... 12 4 Surface