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Organic reactions increasing the absorption index of atmospheric sulfuric acid aerosols
Author(s) -
Nozière B.,
Esteve W.
Publication year - 2005
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2004gl021942
Subject(s) - sulfuric acid , acetaldehyde , radiative forcing , acetone , sulfate , absorption (acoustics) , aerosol , cloud condensation nuclei , formaldehyde , chemistry , condensation , photochemistry , inorganic chemistry , materials science , meteorology , organic chemistry , ethanol , composite material , physics
Unlike most environments present at Earth's surface atmospheric aerosols can be favorable to organic reactions. Among them, the acid‐catalyzed aldol condensation of aldehydes and ketones produces light‐absorbing compounds. In this work the increase of the absorption index of sulfuric acid solutions 50–96 wt. % resulting from the uptake of gas‐phase acetaldehyde, acetone, and 2‐butanone (methyl ethyl ketone), has been measured in the near UV and visible range. Our results indicate that the absorption index between 200 and 500 nm for stratospheric sulfuric aerosols exposed to 100 pptV of acetaldehyde (1 pptV = 10 −12 v/v) would increase by four orders of magnitude over a two‐year lifetime. Rough estimates based on previous radiative calculations suggest that this reaction could result in an increase of the radiative forcing of sulfate aerosols of the order of 0.01 W m −2 , and that these processes are worth further investigation.