The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES)

Abstract

Atmospheric aerosols modulate climate through direct interactions with sunlight and through their indirect role in influencing cloud formation and properties (Andreae and Rosenfeld, 2008; Carslaw et al., 2013). Quantification of marine aerosol-cloud interactions is a major source of uncertainty in estimates of aerosol radiative forcing (Boers and Krummel, 1998; Quinn and Bates, 2011). The sea surface has long been considered a source of aerosols, some of which act as cloud condensation nuclei (CCN) (Charlson et al., 1987). However, it is debatable to what extent marine aerosol influence clouds (Ayers and Cainey, 2007; Quinn and Bates, 2011), especially given that pollution, ship tracks may also contribute to the cloud-active aerosol population (Christensen and Stephens, 2012; Coggon et al., 2012; Hudson and Noble, 2014). Further, even in an unpolluted environment, the relative contributions of primary aerosols arriving in the atmosphere due to wave breaking activities and secondary aerosols (formed from gas phase precursors) are not known. To quantify marine aerosols and their impacts on cloud formation requires additional measurements of aerosol and CCN concentrations are needed, especially in pristine marine environments.