Substantial Seasonal Contribution of Observed Biogenic Sulfate Particles to Cloud Condensation Nuclei.

摘要: Biogenic sources contribute to cloud condensation nuclei (CCN) in the clean marine atmosphere, but few measurements exist constrain climate model simulations of their importance. The chemical composition individual atmospheric aerosol particles showed two types sulfate-containing air masses addition mass-based Estimated Salt particles. Both sulfate lack combustion tracers and correlate, for some conditions, or seawater dimethyl sulfide (DMS) concentrations, which means source was largely biogenic. first type is identified as New Sulfate because large mass fraction (63% sulfate) association with entrainment conditions they could have formed by nucleation free troposphere. second Added (38% sulfate), are preexisting onto additional condensed. accounted 31% (7 cm−3) 33% (36 cm−3) CCN at 0.1% supersaturation late-autumn late-spring, respectively, whereas sea spray provided 55% (13 cm−3) only 4% (4 cm−3) late-spring. Our results show a clear seasonal difference budget, illustrates how important phytoplankton-produced DMS emissions North Atlantic.