The dependence of soot particle ice nucleation ability on its volatile content

Abstract

Aviation soot can affect contrail and cirrus cloud formation and impact climate. A product of incomplete combustion, soot particles are fractal and hydrophobic aggregates comprising carbonaceous spheres with complex physicochemical...

Impacts of Cloud‐Processing on Ice Nucleation of Soot Particles Internally Mixed With Sulfate and Organics

“…(2020) only adds a small amount of H 2 SO 4 ( wt % = 0.0026%–0.32%), as calculated by Gao, Zhou, et al. (2022). Hence, the coating material does not fill new mesopores generated upon soot‐aggregate compaction.…”

“…Produced by the same miniCAST setup under the same fuel to air ratio, the IN ability of size‐selected mBlack and mBrown particles were also tested in Gao, Koch, et al. (2022), Gao, Zhou, et al. (2022), Mahrt, Alpert, et al.…”

“…(2019) suggested that the phase transition to glassy state of organic aerosols requires a low volatility, however, Gao, Koch, et al. (2022) and Mahrt et al. (2018) reported that mBrown contains volatile organics.…”

“…The primary organic content of C 3 H 8 flame soot, including volatile and unsaturated hydrocarbons which are usually hydrophobic, decreases the particle surface wettability and porosity because they can occupy the pore volume (Gao, Koch, et al, 2022;Mahrt et al, 2018). It is reported that some of these primary organics in C 3 H 8 flame soot can be evaporated or oxidized by thermal denuding in a pure nitrogen or air atmosphere at 300°C, thus modifying the soot IN ability (Gao & Kanji, 2022b;Gao, Koch, et al, 2022). The miniCAST setup was operated by the same protocol as used by Gao, Koch, et al (2022) and Mahrt et al (2018) who reported that mBrown contains a larger amount (>20%) of organic matter than mBlack (<20%).…”

“…It is reported that some of these primary organics in C 3 H 8 flame soot can be evaporated or oxidized by thermal denuding in a pure nitrogen or air atmosphere at 300°C, thus modifying the soot IN ability (Gao & Kanji, 2022b;Gao, Koch, et al, 2022). The miniCAST setup was operated by the same protocol as used by Gao, Koch, et al (2022) and Mahrt et al (2018) who reported that mBrown contains a larger amount (>20%) of organic matter than mBlack (<20%). The miniCAST output aerosol flow was dried by a diffusion dryer to decrease the RH w to ∼3%.…”