Production of methanol, acetaldehyde, and acetone in the Atlantic Ocean

Abstract

The biogeochemistry of oxygenated volatile organic compounds (OVOCs) like methanol, acetaldehyde, and acetone in marine waters is poorly understood. We report the first in situ gross production rates for methanol, acetaldehyde, and acetone of 49-103, 25-98, and 2-26 nmol L-1 d-1 over contrasting areas of marine productivity, including oligotrophic gyres and eutrophic upwellings. Photochemical production estimates are mostly negligible for methanol, up to 68% for acetaldehyde and up to 100% of gross production rates for acetone. Microbial surface OVOC oxidation to CO2 accounts for between 10-50% and 0.5-13% of the methanol and acetone losses, respectively, but largely control acetaldehyde concentrations (49-100%). Biological lifetimes in a coastal upwelling vary between ≤1 day for acetaldehyde, to approximately 7 days for methanol and up to ∼80 days for acetone. In open oceanic environments, the lifetime of acetaldehyde ranges between 2 and 5 h, compared to 10-26 days for methanol and 5-55 days for acetone. Key Points To provide net and gross marine OVOC production rates Evaluate the significance of microbial sinks Estimate OVOC biological lifetimes in marine waters ©2013. American Geophysical Union. All Rights Reserved.