Cyanobacterial Emissions Of Biogenic Volatile Organic Compounds: Impacts On The Remote Marine Atmosphere

Atmospheric emissions of biogenic volatile organic compounds (BVOCs) have implications for climate change through the potential to form secondary organic aerosol (SOA) as well as their ability to impact the oxidative capacity of the atmosphere. Despite the importance of BVOCs, there have been relatively few measurements conducted in remote locations where biogenic sources dominate, leading to a discrepancy between modeled and observed SOA yields. Recent evidence has suggested that marine phytoplankton can produce BVOCs, which may be an unaccounted source in aerosol models. This work discusses the results of atmospheric VOC measurements over the North Atlantic Ocean during May 2017. Whole air canister samples were collected along a transect through the North Atlantic from Woods Hole, MA to Bermuda and back with 24 hour stops at nine stations encompassing different cyanobacterial populations. Analysis of selected BVOCs indicated an additional biogenic source of toluene and other BVOCs such as isoprene, with high mixing ratios correlating with a Synechococcus bloom event encountered at station 9. The elevated mixing ratios identified at station 9 were found to increase both hydroxyl reactivities and potential SOA yields compared to the dataset, indicating marine cyanobacteria emissions of VOCs may have a large impact on marine environments.