South Dakota State University Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange Electronic Theses and Dissertations 2020 Volcanic Impact on Stratospheric Chlorine Chemistry and Perchlorate Formation: Evidence from Ice Cores Joshua Andrew Kennedy South Dakota State University Follow this and additional works at: https://openprairie.sdstate.edu/etd Part of the Atmospheric Sciences Commons, Environmental Chemistry Commons, and the Environmental Sciences Commons Recommended Citation Kennedy, Joshua Andrew, "Volcanic Impact on Stratospheric Chlorine Chemistry and Perchlorate Formation: Evidence from Ice Cores" (2020). Electronic Theses and Dissertations. 3953. https://openprairie.sdstate.edu/etd/3953 This Dissertation - Open Access is brought to you for free and open access by Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Open PRAIRIE: Open Public Research Access Institutional Repository and Information Exchange. For more information, please contact [email protected]. VOLCANIC IMPACT ON STRATOSPHERIC CHLORINE CHEMISTRY AND PERCHLORATE FORMATION: EVIDENCE FROM ICE CORES BY JOSHUA ANDREW KENNEDY A dissertation submitted in partial fulfillment of the requirements for the Doctor of Philosophy Major in Chemistry South Dakota State University 2020 ii DISSERTATION ACCEPTANCE PAGE Joshua Andrew Kennedy This dissertation is approved as a creditable and independent investigation by a candidate for the Doctor of Philosophy degree and is acceptable for meeting the dissertation requirements for this degree. Acceptance of this does not imply that the conclusions reached by the candidate are necessarily the conclusions of the major department. Jihong Cole-Dai Advisor Date Douglas Raynie Department Head Date Dean, Graduate School Date iii ACKNOWLEDGEMENTS I would like to thank all those that helped me through the last several years of graduate school. Foremost, thanks to my wife, Vanessa, for all of her encouragement and support, making this possible. My daughters, Gwenyth and Zoë, thanks you for giving me inspiration to succeed and someone to make proud. I want to thank all of my family for enduring the last ten years alongside me, and for propping me up through difficult times. To my advisor, Jihong Cole-Dai, thank you for providing mentorship, guidance, end encouragement throughout my graduate studies. I also would like to send my appreciation the members of my committee, Drs. Brian Logue, Matt Miller, and Keith Underwood, for their service and feedback. For inspiring me to study areas of chemistry, geology, and Earth science, I thank Drs. Tom Jempty and Bruce Darling at Austin Community College. Last, my thanks go out to all those present and past members of the group that contributed to my sanity, research, and good times over the last couple years; Carleigh Larrick, Tommy Cox, Joe Gibson, Amanda Shea, Kari Peterson, and of course, Dave Ferris. As I write this, the number of COVID-19 cases and deaths during this pandemic is peaking across the world and shows no signs of slowing. The university is closed, all classes have moved online, and all work is being done remotely. Unemployment is at an all-time high in the US, and the economy is at record lows. I cannot help but be reminded of Isaac Newton, who devised many of his theories on optics, physics, and calculus during a break from his own university studies during an outbreak of bubonic plague. Times such iv as these may be exceptional, but also show how we can overcome tremendous adversity and serve as testament to the tenacity of mankind. Tigger. Buddy. I knew you weren’t making it out of South Dakota. v CONTENTS List of Tables .......................................................................................................... vii List of Figures ........................................................................................................ viii Abstract ................................................................................................................... xi 1.0 Introduction .................................................................................................. 1 1.1 Volcanic Eruptions and the Environment ................................................. 1 1.2 Perchlorate in the Environment ................................................................ 3 1.3 Sources of Environmental Perchlorate ..................................................... 5 1.4 Overview of Ice Core Chemistry .............................................................. 11 1.5 Research Objectives ................................................................................ 13 2.0 Methods ...................................................................................................... 15 2.1 Sample Collection .................................................................................... 15 2.2 Sample Preparation ................................................................................. 16 2.3 Analytical Methods ................................................................................. 17 2.3.1 Ion Chromatography/Conductivity Detection .................................. 17 2.3.2 Ion Chromatography/Tandem Mass Spectroscopy .......................... 19 2.4 Ice Core Dating ........................................................................................ 20 2.4.1 Annual Layer Counting ...................................................................... 20 2.4.2 Sub Annual Dating ............................................................................. 28 2.6 Data Processing ....................................................................................... 30 2.6.1 Flux Calculation and Use ................................................................... 30 2.6.2 Time Series Smoothing ...................................................................... 32 2.6.3 Frequency Domain Time Series Analysis ........................................... 35 2.6.4 Time Domain Time Series Decomposition ........................................ 37 3.0 Relationship of Perchlorate to Stratospheric Chlorine Chemistry and Ozone 39 3.1 Overview of Stratospheric Chlorine Chemistry ....................................... 40 3.2 Mechanisms of Atmospheric Perchlorate Formation ............................. 45 3.3 Seasonality of Perchlorate ...................................................................... 50 3.3.1 Spectral Analysis of the Summit Perchlorate Record ....................... 51 3.3.2 Time Series Decomposition of the Summit Perchlorate Record ...... 54 3.4 Relationship to Ozone ............................................................................. 61 3.4.1 Sub Annual Relationship ................................................................... 61 vi 3.4.2 Annual Relationship .......................................................................... 64 4.0 Response of Perchlorate to Volcanic Eruptions.......................................... 69 4.1 Observation of Volcanic Perchlorate Signals .......................................... 70 4.2 Magnitude of Perchlorate Response to Katmai and Huaynaputina ....... 74 4.3 Perchlorate Response Signal Characteristics .......................................... 83 4.3.1 Timing of Perchlorate and Sulfate Concentration Peaks .................. 84 4.3.2 Diffusion of Perchlorate in Ice Cores ................................................ 86 4.4 Perchlorate Formation after Major Volcanic Eruptions .......................... 94 4.4.1 Primary Volcanically Perturbed Pathways ........................................ 95 4.4.2 Other Volcanically Perturbed Pathways ........................................... 99 5.0 Conclusions and Future Work ................................................................... 106 5.1 Conclusions............................................................................................ 106 5.2 Future Work .......................................................................................... 108 Appendix A, Visual Basic LOESS Smoothing Macro for Excel .............................. 111 Appendix B, Fast Fourier Transform Script for R ................................................ 113 Appendix C, Time Series Analysis Script for R ..................................................... 114 Appendix D, Forecasting Script for R .................................................................. 115 References .......................................................................................................... 116 vii LIST OF TABLES Table 1. DD assignment for the year 1996 in the SM07C2 core. This interval comprised 12 samples and covers the depths from 7.124 to 6.514 meters (27.59 cm w.e.). ........................................................................................................................................... 29 Table 2. Table of volcanic eruptions where a clear perchlorate response was identified. .......................................................................................................................... 72 Table 3. Volcanic sulfate signals and perchlorate responses for identified eruptions, with total sulfate and perchlorate fluxes for that section of ice. ................... 80 viii LIST OF FIGURES Figure 1. Chromatogram of 25 µg kg-1 cation calibration standard, CS12 analytical -1 + + column (2mm x 250mm), 12 mM H2SO4,