AAAR 34th Annual Conference
October 12 - October 16, 2015
Hyatt Regency
Minneapolis, Minnesota, USA
Abstract View
Long-term Comparison of Thermal-optical Transmittance Elemental Carbon and Optical Black Carbon in the Arctic
Philip K. Hopke, YUANYUAN ZHANG, Clarkson University
Abstract Number: 192 Working Group: Remote and Regional Atmospheric Aerosols
Abstract Black carbon (BC) is carbonaceous particles that strongly absorb light. Thus BC has a significant effect on climate change and global warming. Often in the literature, the term BC is used interchangeably with the term elemental carbon (EC). However, BC and EC are different because each is defined operationally. For BC, light absorption measures the “blackness” of the particle while for EC; the measurement is by a thermal-optical method. BC is important in the Arctic because the deposited BC particles can decrease the albedo and cause ice and snow melting. Limited Arctic black carbon projects had been developed long-term black carbon concentrations ([BC]) to explore the trends in BC. Generally, these projects used light absorption (Aethalometer or OT-21). In the current study, we used the NIOSH thermal-optical transmittance (TOT) protocol to measure thermal [EC] in samples collected at Alert, Nunavut, Canada (82.5°N, 62.5°W) from 1981 to 2008. The samples were collected on 8” x 10” Whatman 41 filters that were cut into 1” strips for analysis. Each strip was dissolved in 70% ZnCl2 solution and filtered onto baked quartz filters for EC analysis. These data permit the comparison of the long-term thermal [EC] results with [BC] measured at Alert since 1989 using an Aethalometer. These results will provide additional data on carbonaceous particles (EC) relative to the long-term black carbon aerosol in the Arctic. Such information will be useful for better understanding global atmospheric chemistry and climate change, particularly with respect to Arctic warming.