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Citation
Tags
HERO ID
2037637
Reference Type
Journal Article
Title
Hygroscopic Growth and Deliquescence of NaCl Nanoparticles Mixed with Surfactant SDS
Author(s)
Harmon, CW; Grimm, RL; Mcintire, TM; Peterson, MD; Njegic, B; Angel, VM; Alshawa, A; Underwood, JS; Tobias, DJ; Gerber, RB; Gordon, MS; Hemminger, JC; Nizkorodov, SA
Year
2010
Is Peer Reviewed?
Yes
Journal
Journal of Physical Chemistry B
ISSN:
1520-6106
EISSN:
1520-5207
Volume
114
Issue
7
Page Numbers
2435-2449
PMID
20108956
DOI
10.1021/jp909661q
Web of Science Id
WOS:000274578500015
Abstract
Several different ice nucleation parameterizations in two different General Circulation Models (GCMs) are used to understand the effects of ice nucleation on the mean climate state, and the Aerosol Indirect Effects (AIE) of cirrus clouds on climate. Simulations have a range of ice microphysical states that are consistent with the spread of observations, but many simulations have higher present-day ice crystal number concentrations than in-situ observations. These different states result from different parameterizations of ice cloud nucleation processes, and feature different balances of homogeneous and heterogeneous nucleation. Black carbon aerosols have a small (-0.06 Wm(-2)) and not statistically significant AIE when included as ice nuclei, for nucleation efficiencies within the range of laboratory measurements. Indirect effects of anthropogenic aerosols on cirrus clouds occur as a consequence of increasing anthropogenic sulfur emissions with different mechanisms important in different models. In one model this is due to increases in homogeneous nucleation fraction, and in the other due to increases in heterogeneous nucleation with coated dust. The magnitude of the effect is the same however. The resulting ice AIE does not seem strongly dependent on the balance between homogeneous and heterogeneous ice nucleation. Regional effects can reach several Wm(-2). Indirect effects are slightly larger for those states with less homogeneous nucleation and lower ice number concentration in the base state. The total ice AIE is estimated at 0.27 +/- 0.10 Wm(-2) (1 sigma uncertainty). This represents a 20% offset of the simulated total shortwave AIE for ice and liquid clouds of -1.6 Wm(-2).
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