Poster's note: relevant to MCB, and to an extent to cirrus stripping and SAI rainout
Download http://advances.sciencemag.org/content/1/6/e1500157.full-text.pdf+html View online http://advances.sciencemag.org/content/1/6/e1500157.full Natural aerosols explain seasonal and spatial patterns of Southern Ocean cloud albedo Daniel T. McCoy Susannah M. Burrows Robert Wood1, Daniel P. Grosvenor Scott M. Elliott Po-Lun Ma Phillip J. Rasch Dennis L. Hartmann E-mail: [email protected] (D.T.M.); [email protected] (S.M.B.) Science Advances 17 Jul 2015: Vol. 1, no. 6, e1500157 DOI: 10.1126/sciadv.1500157 Abstract Atmospheric aerosols, suspended solid and liquid particles, act as nucleation sites for cloud drop formation, affecting clouds and cloud properties—ultimately influencing the cloud dynamics, lifetime, water path, and areal extent that determine the reflectivity (albedo) of clouds. The concentration Nd of droplets in clouds that influences planetary albedo is sensitive to the availability of aerosol particles on which the droplets form. Natural aerosol concentrations affect not only cloud properties themselves but also modulate the sensitivity of clouds to changes in anthropogenic aerosols. It is shown that modeled natural aerosols, principally marine biogenic primary and secondary aerosol sources, explain more than half of the spatiotemporal variability in satellite-observed Nd. Enhanced Nd is spatially correlated with regions of high chlorophyll a, and the spatiotemporal variability in Nd is found to be driven primarily by high concentrations of sulfate aerosol at lower Southern Ocean latitudes (35o to 45oS) and by organic matter in sea spray aerosol at higher latitudes (45o to 55oS). Biogenic sources are estimated to increase the summertime mean reflected solar radiation in excess of 10 W m–2 over parts of the Southern Ocean, which is comparable to the annual mean increases expected from anthropogenic aerosols over heavily polluted regions of the Northern Hemisphere. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/geoengineering. For more options, visit https://groups.google.com/d/optout.
