Classifying Ash Cloud Attributes of Eyjafjallajökull Volcano, Iceland, using Satellite Remote Sensing by Katrina Jane Gressett A Thesis Presented to the FACULTY OF THE USC DORNSIFE COLLEGE OF LETTERS, ARTS AND SCIENCES University of Southern California In Partial Fulfillment of the Requirements for the Degree MASTER OF SCIENCE (GEOGRAPHIC INFORMATION SCIENCE AND TECHNOLOGY) May 2021 Copyright © 2021 Katrina Jane Gressett To Mom and Dad, thank you for encouraging my curiosity. To Reilly, Kaylee, and Juniper, thank you for knowing exactly when I needed to play. ii Acknowledgements I am grateful to my mentor, Professor Fleming, for the direction I needed and my other faculty advisors who assisted me when needed. I want to thank my manager, Dr. Cormode, for his understanding and words of wisdom and my employer, Bay4 Technical Services, which allowed me time away from the office to complete this work. I am grateful for the data provided to me by the EARLINET Project and NASA. iii Table of Contents Dedication ....................................................................................................................................... ii Acknowledgements ........................................................................................................................ iii List of Tables ................................................................................................................................ vii List of Figures .............................................................................................................................. viii Abbreviations .................................................................................................................................. x Abstract ......................................................................................................................................... xii Chapter 1 Introduction .................................................................................................................... 1 1.1. Study Objectives .................................................................................................................1 1.2. Motivation ...........................................................................................................................2 1.2.1. Volcanic Health Hazards ...........................................................................................2 1.2.2 Ash Cloud Forecasts ...................................................................................................3 1.3. Study Area ..........................................................................................................................5 Chapter 2 Literature Review ........................................................................................................... 8 2.1. Remote Sensing of Volcanic Ash .......................................................................................8 2.1.1. MODIS Instrument Package ....................................................................................10 2.1.2. InSAR Remote Sensing ...........................................................................................10 2.2. Ground-Based LiDAR ......................................................................................................11 2.3. Eruption Cloud Forecasting ..............................................................................................11 2.4. Volcanic Effects on Aircraft .............................................................................................13 Chapter 3 Methods ........................................................................................................................ 15 3.1. Data Sources .....................................................................................................................15 3.1.1. EARLINET Data .....................................................................................................17 3.1.2. MODIS Data ............................................................................................................18 3.2. EARLINET Processing Overview ....................................................................................19 iv 3.2.1. Database Manipulation ............................................................................................20 3.2.2. Daily Interpolations .................................................................................................21 3.2.3. Interpolations Tested ................................................................................................21 3.2.4. Inverse Distance Weighting .....................................................................................24 3.2.5. Cross-Validation ......................................................................................................25 3.3. MODIS Processing Overview...........................................................................................26 3.3.1. MODIS Data Import and Corrections ......................................................................28 3.3.2. Radiance Values.......................................................................................................28 3.3.3. Image Mosaic ...........................................................................................................30 3.3.4. Brightness Temperature ...........................................................................................31 3.3.5. Ash Cloud Classification .........................................................................................31 3.4. Flight Path Proximity ........................................................................................................32 Chapter 4 Results .......................................................................................................................... 34 4.1. EARLINET Interpolation .................................................................................................34 4.2. MODIS Brightness Temperature Difference ....................................................................41 4.3. Flight Paths .......................................................................................................................48 Chapter 5 Discussion .................................................................................................................... 50 5.1. Discussion .........................................................................................................................50 5.2. Limitations ........................................................................................................................51 5.2.1. EARLINET Interpolations .......................................................................................51 5.2.2. MODIS and BTD .....................................................................................................52 5.3. Future Research ................................................................................................................53 5.3.1. Ash Cloud Thickness ...............................................................................................53 5.3.2. Eruptive Volume ......................................................................................................53 5.3.3. Ash Cloud Density Contours ...................................................................................54 v 5.4. Conclusions .......................................................................................................................54 References ..................................................................................................................................... 56 Appendix: EARLINET Sites Active By Day ............................................................................... 60 vi List of Tables Table 1. Data used in this project.................................................................................................. 16 Table 2. Radiance scale and offset values provided by NASA for each of the three bands used in this project. .................................................................................................................................... 29 vii List of Figures Figure 1. The volcanic ash advisory forecast for April 15 until April 16, 2010. ............................ 4 Figure 2. The study area showing Iceland, central European counties, and the location of the Eyjafjallajökull volcano. ................................................................................................................. 6 Figure 3. Time snapshots of ash mass loading produced by the WRF-Chem model reproduced from Webley et al. (2012). ............................................................................................................ 13 Figure 4. The EARLINET stations used in this project. ............................................................... 18 Figure 5. The workflow for processing EARLINET data. ........................................................... 20 Figure 6. The left image displays the RBF with Spline interpolation, while the right displays the IDW interpolation. ........................................................................................................................ 23 Figure 7. The results of the kriging interpolation. ........................................................................ 24 Figure 8. The workflow for the MODIS data. .............................................................................. 27