Impact of nucleation on global CCN

By J. Merikanto, Dominick V. Spracklen, G. Mann, Steven J. Pickering, K. Carslaw. 2009

829 citations recorded by the source corpus.

Abstract. Cloud condensation nuclei (CCN) are derived from particles emitted directly into the atmosphere (primary emissions) or from the growth of nanometer-sized particles nucleated in the atmosphere. It is important to separate these two sources because they respond in different ways to gas and particle emission control strategies and environmental changes. Here, we use a global aerosol microphysics model to quantify the contribution of primary and nucleated particles to global CCN. The model considers primary emissions of sea spray, sulfate and carbonaceous particles, and nucleation processes appropriate for the free troposphere and boundary layer. We estimate that 45% of global low-level cloud CCN at 0.2% supersaturation are secondary aerosol derived from nucleation (ranging between 31–49% taking into account uncertainties in primary emissions and nucleation rates), with the remainder from primary emissions. The model suggests that 35% of CCN (0.2%) in global low-level clouds were created in the free and upper troposphere. In the marine boundary layer 55% of CCN (0.2%) are from nucleation, with 45% entrained from the free troposphere and 10% nucleated directly in the boundary layer. Combinations of model runs show that primary and nucleated CCN are non-linearly coupled. In particular, boundary layer nucleated CCN are strongly suppressed by both primary emissions and entrainment of particles nucleated in the free troposphere. Elimination of all primary emissions reduces global CCN (0.2%) by only 20% and elimination of upper tropospheric nucleation reduces CCN (0.2%) by only 12% because of the increased contribution from boundary layer nucleation.

Subfields: Atmospheric Science, Global and Planetary Change, Health, Toxicology and Mutagenesis

View Paper: https://www.semanticscholar.org/paper/916eaf3aaa7a3937d629ce2bddbf4a6fbf091823

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Citations in the corpus

Atmospheric new particle formation and growth: review of field observations (2018, background): “…source of the total particle number concentration, and an important contributor to the CCN budget, in the global troposphere (Spracklen et al 2006, Merikanto et al 2009, Pierce and Adams 2009, Yu and Luo 2009, Makkonen et al 2012, Dunne et al 2016, Gordon et al 2017) as well as in the continental…”
Emulation of a complex global aerosol model to quantify sensitivity to uncertain parameters (2011, methodology): “This interaction effect is plausible since nucleation is an important source of CCN in this part of the atmosphere (Merikanto et al., 2009), and the nucleation rate is strongly affected by the surface area of existing particles, which itself is affected by large sea spray particles and by the partic”
Lightning enhancement over major oceanic shipping lanes (2017, background): “…invigoration [Koren et al., 2005], results in a potential sensitivity of lightning and storm vertical development to human activities, which have perturbed CCN concentrations on regional and global scales [Boucher and Lohmann, 1995; Pierce et al., 2007; Merikanto et al., 2009; Dunne et al., 2016].”
Cloud condensation nuclei production associated with atmospheric nucleation: a synthesis based on existing literature and new results (2012, background): “Recent developments in size resolved chemical measurements have allowed for detailed investigations between the CCN spectrum, aerosol number size distribution, and sizeresolved chemical composition of the aerosol.”
Molecular understanding of sulphuric acid–amine particle nucleation in the atmosphere (2013, background): “Hence the first positively charged cluster is a DMA?H(1) ion together with a single SA?DMA acid–base pair (1, 2).”
JournalofGeophysicalResearch : Atmospheres Causes and importance of new particle formation in the present-day and preindustrial atmospheres (2017, neutral): “As noted by Merikanto et al. [2009], the fraction of CCN from NPF increases with altitude and is higher in marine regions than over land.”
Modeling the formation and growth of atmospheric molecular clusters: A review (2020, background): “The interactions between aerosol particles and clouds remain the least understood process in global climate estimation (IPCC), and presently, up to half the number of CCN is believed to originate from new particles formed in the atmosphere from gas-phase molecules (Merikanto et al., 2009).”
EUCAARI ion spectrometer measurements at 12 European sites – analysis of new particle formation events (2010, background): “Modeling studies indicate that nucleation may be a significant source of new CCN in the global atmosphere (e.g. Spracklen et al., 2008; Merikanto et al., 2009; Pierce and Adams, 2009).”
Anthropogenic and Natural Radiative Forcing (2014, background): “There is evidence from laboratory, field and modelling studies that ionization from cosmic ray flux may enhance aerosol nucleation in the free troposphere (Merikanto et al., 2009; Mirme et al., 2010; Kirkby et al., 2011).”
Intercomparison and evaluation of global aerosol microphysical properties among AeroCom models of a range of complexity (2014, background): “The aircraft measurements very clearly show a distinct maximum in particle concentrations in the free and upper troposphere, which has been shown to provide an important source of CCN in marine regions (Merikanto et al., 2009).”