Yasemin Erboy, W. Smethie
Feb 8, 2022
Citations
11
Influential Citations
92
Citations
Quality indicators
Journal
Coexistence in Ecology
Abstract
Sulfur hexafluoride (SF 6 ) is a greenhouse gas formed through anthropogenic processes such as the manufacture of high voltage equipment. Recently trifluoromethyl sulfur pentafluoride (SF 5 CF 3 ) has been tied to SF 6 because of their parallel trend of increase in the atmosphere. The purpose of this project was to study the variability of SF 5 CF 3 using gas chromatography to confirm its use as a tracer. The main question was whether SF 5 CF 3 has a unique rate of increase, meaning that it has different sources than SF 6 ; or whether it correlates with SF 6 , in which case it could be a by-product of SF 6 production. Dichlorodifluoromethane (referred to as F12) was also studied to serve as a basis for the accuracy of the measurements made in Palisades, New York; an ideal location to study the compounds’ local sources. SF 5 CF 3 did not correlate significantly with SF 6 , F12 or any atmospheric variable studied, whereas SF 6 was seen to correlate with relative humidity and atmospheric CO2 concentration. Compared to historical data, our SF 6 or F12 values were not as high; for F12 this was expected since it was recently discontinued, and for SF 6 it could be due to the short sampling period. SF 5 CF 3 also did not exhibit as much variability, which can be explained by the atmospheric mixing ratio of SF 5 CF 3 (Busenberg and Plummer, 2008) which appears to have leveled after 2000, due to increased awareness of its potency as a greenhouse gas. The effect of wind direction was also studied: very high SF 6 values were observed from highly urbanized areas in NE and SW as well as Manhattan. Both SF 6 and SF 5 CF 3 peaked with winds from N, indicating Dutchess County where IBM produces plasma in semiconductor etching. These results have proved that the atmospheric variability of SF 5 CF 3 is easily documented and that the compounds may have a complex relationship with their sources, which merits further research.