Preliminary results from implementation of a new marine organic matter parameterization

Abstract

Cloud droplet number concentrations are especially susceptible to changes in aerosol concentrations in remote marine areas, where perturbations to CCN concentrations under pristine conditions have stronger radiative impacts than in polluted continental air.  Field observations and laboratory studies during the past 5-10 years have demonstrated that primary organic matter associated with sea spray aerosol may be an important, previously neglected source of CCN in pristine, remote marine air.  Our group recently developed a new approach to parameterizing these emissions (Burrows et al., 2014).  We will present an analysis of satellite observations, showing that modelled organic matter from phytoplankton blooms statistically predicts a portion of the geographic and seasonal variability in cloud drop number concentration over the Southern Ocean, with a resultant summertime radiative forcing on the order of 10 W m-2, averaged over the Southern Ocean.  We will present early results from an implementation of the newly-developed OCEANFILMS parameterization for emissions of marine organic matter with sea spray in CESM1.2, which we anticipate will be integrated into ACME, following evaluation.

Burrows_marine_organic_aerosol_ACME_all-hands_poster_2015.pdf