*********************************
There is now a CONTENT FREEZE for Mercury while we switch to a new platform. It began on Friday, March 10 at 6pm and will end on Wednesday, March 15 at noon. No new content can be created during this time, but all material in the system as of the beginning of the freeze will be migrated to the new platform, including users and groups. Functionally the new site is identical to the old one. webteam@gatech.edu
*********************************
Prof. Sally Ng
Summary Sentence: A seminar by Dr. Andrew May, School of Earth and Atmospheric Sciences
Full Summary: No summary paragraph submitted.
Andrew MayThis presentation focuses on our participation in the Fire Influence on Regional and Global Environments Experiment (FIREX).
In this work, we deployed different black carbon (BC) instruments that utilize different techniques to quantify BC, including filter-based light absorption, in situ light absorption, laser-induced incandescence, and thermal-optical analysis. Experiments were conducted using “fresh” open biomass burning smoke samples collected from controlled burns at the US Forest Services’s Fire Sciences Laboratory in Missoula, MT.
Through statistical methods (principle component analysis with k-means clustering), we categorized each fire into distinct groups based on its chemical and optical properties. We demonstrated that when biomass burning smoke is most optically similar to “pure” BC, the disparate measurement techniques have the best agreement, but this agreement worsens as the smoke becomes “browner”.
Consequently, to relate BC measurements taken by different instruments from biomass burning smoke, information about the chemical and optical properties of the smoke aerosols may be necessary, especially because most real-world smoke plumes are likely dissimilar to “pure” BC.
Time permitting, I will also present briefly on an unrelated project that deals with a current “hot” topic for environmental engineering – per- and poly-fluorinated alkyl substances (PFAS).
Most of the concerns around PFAS is drinking water source contamination, which has traditionally been linked to wastewater discharge from industrial facilities and infiltration into groundwater at sites where PFAS are utilized. However, we have demonstrated a probable link between air emissions of PFAS and drinking water source contamination using field observations of PFAS in surface waters and soils coupled with an atmospheric dispersion model.
