06 January 2016

Marine Organic Chemistry: Global Distribution and Surface Activity of Macromolecules in Offline Simulations


Bubbles bursting at the ocean surface produce sea spray aerosol droplets. This process changes the chemistry of sea spray by transferring organic matter from ocean water into the marine boundary layer. These bubbles can contain several classes of organic compounds that are emitted and transported through the air. In the atmosphere, these particles can affect the properties of clouds, impacting the amount of sunlight they reflect away from the Earth. A team of scientists, including a U.S. Department of Energy researcher at Pacific Northwest National Laboratory, found that emitted aerosol particles containing long-chain carbon molecules can contribute significantly to the atmospheric particle population and affect the concentrations of cloud condensation nuclei (CCN). The CCN, in turn, influence how clouds form and develop, and impact the climate by modifying Earth’s albedo (reflectivity). The team developed an observational approach that accounts more completely for macromolecular chemical resolution within the sea and then utilizes the distributions to predict the organic mass composition in fine-mode sea spray aerosol. This new approach permits estimation of oceanic concentrations and bubble film surface coverages for several classes of organic compounds. The research may provide useful mapped estimates of macromolecular distributions as a research guide for aerosol studies, such as the design of ship and aircraft-based experiments.

Susannah Burrows
Pacific Northwest National Laboratory

Participants at Los Alamos National Laboratory and New Mexico Tech thank the U.S. Department of Energy SciDAC program (Scientific Discovery for Advanced Computing), and specifically its ACES4BGC project (Applying Computationally Efficient Schemes for Biogeochemical Cycles). SMB was supported by the Office of Science Biological and Environmental Research division of the U.S. Department of Energy, as part of an Earth System Modeling Program. Additionally, contributions by AAF and LMR were supported by NSF grants OCE-1129580 and AGS-1360645. JKM and RTL acknowledge support from the DOE Office of Biological and Environmental Research, Grant ER65358. Validation exercises were conducted as part of the DOE marine biogeochemistry Benchmarking and Feedbacks effort.