The examination of size distribution, composition and elemental concentration of the aerosol species in the Shenandoah National Park and Manassas, Virginia regions was investigated during a three month summertime period. The relationships between the above mentioned parameters along with prevalent meteorological patterns, emission sources and associated topography were used to determine the geographical origin, aerosol age, and numerous other chemical and physical characteristics of the ambient aerosol. Data for the study were obtained by ground based sampling of particulates and from in situ sampling from an airborne sampling platform. The need for continued surveillance along with improved methods of characterization of the ambient aerosol species is discussed. / Master of Science