Author: Benjamin  Lancaster,   (University of North Carolina Wilmington)

Designation: 

Description:
Gas phase and rainwater ethanol concentrations have increased dramatically in the last decade as a result of increasing use of ethanol as a biofuel, followed by a sudden decrease in 2020. Rainwater ethanol concentrations correlated positively with the number of vehicle kilometers driven in North Carolina and South Carolina over this time period highlighting the importance of vehicle exhaust on controlling the abundance of the alcohol in this region. The global pandemic and resulting state mandated lockdowns provided a unique opportunity to examine the effect of decreased vehicle km  (estimated to be an approximately 12% decrease in km driven in the southeastern USA in 2020) on ethanol concentrations in air and rain. This resulted in a decrease in the volume weighted concentration of ethanol in rain from 733 nM in 2017, and 506 nM in the first half of 2018, to 123 nM during July through September of 2020. Gas phase concentrations decreased during the summer of 2020 to 1.3 &pm 0.3 ppbv from 4.7  &pm 1.1 ppbv in July 2016. Reduced concentrations of atmospheric ethanol caused by shifts in driving habits will have important implications for air quality because of potential reductions in smog formation as well as reduced concentrations of ozone, acetaldehyde and peroxyacetly nitrate (PAN) . Data presented in this presentation are important because they suggest that changing commuting habits and a switch to electric based vehicles will have a significant impact on the amount of ethanol in the atmosphere.

Category: Scientific Program Abstract > Special Sessions > SS14 Blue Carbon science for a sustainable future