Black carbon, the product of the incomplete combustion of biomass and fossil fuels, is known to contribute to global warming and adversely affect health. Scientists have developed many techniques that determine the chemical, physical and optical properties, size and mass concentration of black carbon. Quantifying the optical properties (scattering and absorption), and the mass concentrations will help to better understand black carbon’s contribution to radiative forcing and human health. However, not all techniques produce the same answer. Many commercial filter-based instruments do not produce the same results as other in situ techniques or thermal optical analysis methods. Thus, there is an urgent need in the black carbon community to develop standard reference materials and calibration techniques for different instrumentation. Commercial filter-based instruments were characterized using a validated cavity ring down spectrometer and calibrated photoacoustic spectrometer to determine the extinction and absorption response of these filter-based techniques, respectively with a potential surrogate BC material. These experiments conducted with in situ techniques will better validate the measurements of the filter-based instruments.
Courtney Grimes is currently a doctoral student in the Chemistry Department at the University of Maryland, College Park. Her research focus is Atmospheric Chemistry, specifically light absorbing aerosols. She conducts her Ph.D. research at the National Institute of Standards and Technology (NIST). Courtney first became interested in Atmospheric Chemistry during the AMGEN summer research program at UC Berkeley in 2012. As an undergraduate student she received a scholarship from the American Chemical Society (ACS) and graduated cum laude with a Bachelor of Science degree in Chemistry in 2013 from Hofstra University. She has been a mentor to a high school student.