Marine low clouds play an important role in the climate system, and their properties are sensitive to cloud condensation nuclei concentrations. While new particle formation represents a major source of cloud condensation nuclei globally, the prevailing view is that new particle formation rarely occurs in remote marine boundary layer over open oceans. Here we present evidence of the regular and frequent occurrence of new particle formation in the upper part of remote marine boundary layer following cold front passages. The new particle formation is facilitated by a combination of efficient removal of existing particles by precipitation, cold air temperatures, vertical transport of reactive gases from the ocean surface, and high actinic fluxes in a broken cloud field. The newly formed particles subsequently grow and contribute substantially to cloud condensation nuclei in the remote marine boundary layer and thereby impact marine low clouds.


Civil, Architectural and Environmental Engineering


Funding was obtained from the Atmospheric System Research (ASR) program (Office of Biological and Environmental Research of US DOE, under contract DE-SC0020259 and DE-AC02- 98CH10886) and NASA NAAMES project within the Earth Venture Suborbital-2 Program (NNH13ZDA001N-EVS2).

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Article - Journal

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Publication Date

22 Jan 2021