A Southeastern United States Site Characterization Involving Black Carbon Aerosol Concentrations and Meteorological Variables

LEWITSKY, JEFFREY RYAN. A Southeastern United States Site Characterization Involving Black Carbon Aerosol Concentrations and Meteorological Variables. (Under the direction of Dev Dutta S. Niyogi and Fred H. M. Semazzi). Aerosols present in the Earth’s atmosphere play a crucial role in global meteorological conditions. If there is a larger concentration of aerosols then there may be a resulting variance in the weather and climate. One particular aerosol, which was measured and observed for this study, is black carbon. The presence of black carbon concentrations could result in a variance of certain weather variables at any given location. Black carbon aerosols absorb incoming solar radiation, which can impact the vertical temperature profile. A comparison of results can be made between weather and climate conditions in which a significant amount of black carbon is present, and other conditions with minimal amounts of black carbon in the troposphere. The observed data analyzed is from the Lake Wheeler site, a semi-urban location near the threshold of the piedmont and coastal plain zones of central North Carolina. The period for evaluation is June 2003 through May 2004. The weather variables that were closely examined include air temperature, dewpoint temperature, relative humidity, wind speed, and wind direction. In addition, radiation data was collected and analyzed including solar radiation, photosynthetically active radiation (PAR), net irradiance, diffuse radiation and direct radiation. Aerosol optical depths (AOD), which are the measurement of light attenuation at specified wavelengths, were also collected and evaluated in both the ultraviolet and visible light spectrums. This was done in order to determine any relationships between black carbon concentrations and AODs at certain wavelengths. After examining the year’s worth of data a site characterization involving the black carbon concentrations and meteorological variables for the Raleigh, NC location was devised. A Southeastern United States Site Characterization Involving Black Carbon Aerosol Concentrations and Meteorological Variables By Jeffrey R. Lewitsky A thesis submitted to the Graduate Faculty of North Carolina State University in partial fulfillment of the requirements for the Degree of Master of Science MARINE, EARTH, AND ATMOSPHERIC SCIENCES Raleigh, North Carolina 2006 APPROVED BY: __________________ _________________ Dr. Dev Dutta S. Niyogi Dr. Fred H. M. Semazzi (Co-Chair of Advisory Committee) (Co-Chair of Advisory Committee) __________________ _________________ Dr. Gerald S. Janowitz Dr. William F. Barnard ii DEDICATION Dedicated to Lorenzo Piczon Agustin iii BIOGRAPHY Jeffrey Lewitsky was born in the city of Welland, Ontario, Canada on 2 November 1980. He moved to Raleigh, North Carolina in August 1990, where he attended Ravenscroft School for his early education. Jeffrey graduated from high school in June 1998. In August 1998 he went on to study at the University of North Carolina at Asheville, where he would eventually receive his Bachelor’s of Science degree in Atmospheric Science with a concentration in Weather Forecasting in May 2002. He went on to pursue his Masters of Science degree in Atmospheric Sciences at North Carolina State University in August 2003. He currently works for the National Weather Service in Eureka, CA. iv ACKNOWLEDGEMENTS The author is truly grateful for all of the advice and inspiration that the members of his advisory committee have given over the past 3 years. Dr. Niyogi helped to develop the original idea of a study involving black carbon aerosols and meteorological variables by utilizing data from a site near Raleigh, North Carolina. The author would also like to thank the department of Marine, Earth and Atmospheric Sciences for providing financial assistance from 2004-2005, which ultimately allowed this project to continue. Additionally the author would like to thank the National Weather Service weather forecast office in Eureka, California for supporting him in his pursuit of this degree. The author would especially like to thank his parents, Jerry and Mary Lewitsky of Raleigh, North Carolina, his sister Miranda Lewitsky of Austin, Texas, all of his family in Canada and abroad. In addition, Jeffrey is extremely thankful and appreciative of the support and kindness of his lifelong friends Lorenzo Agustin and Angela DePoy. Each of the above has provided continuing encouragement and strength throughout the author’s time at North Carolina State University and beyond. v TABLE OF CONTENTS List of Figures. vi List of Tables. vii