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Impacts of meteoric sulfur in the Earth's atmosphere
Author(s) -
Gómez Martín Juan Carlos,
Brooke James S. A.,
Feng Wuhu,
Höpfner Michael,
Mills Michael J.,
Plane John M. C.
Publication year - 2017
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1002/2017jd027218
Subject(s) - sulfate aerosol , stratosphere , sulfur , flux (metallurgy) , atmospheric sciences , sulfate , atmosphere (unit) , meteoric water , aerosol , volcano , sulfur cycle , altitude (triangle) , chemistry , geology , meteorology , physics , hydrothermal circulation , geochemistry , geometry , mathematics , organic chemistry , seismology
A meteoric sulfur input function and a sulfur ion chemistry scheme have been incorporated into a chemistry‐climate model, in order to study the speciation of sulfur between the stratosphere and the thermosphere (~20–120 km) and the impact of the sulfur input from ablation of cosmic dust. The simulations have been compared to rocket observations of SO + between 85 and 110 km, MIPAS observations of SO 2 between 20 and 45 km, and stratospheric balloon‐borne measurements of H 2 SO 4 vapor and sulfate aerosol. These observations constrain the present‐day global flux of meteoric sulfur to ≤1.0 t S d −1 , i.e., 2 orders of magnitude smaller than the flux of S into the stratosphere from OCS photooxidation and explosive volcanic SO 2 injection. However, the meteoric sulfur flux is strongly focused into the polar vortices by the meridional circulation, and therefore, the contribution of SO 2 of meteoric origin to the polar upper stratosphere during winter is substantial (~ 30% at 50 km for a flux of 1.0 t S d −1 ). The Antarctic spring sulfate aerosol layer is found to be very sensitive to a moderate increase of the input rate of meteoric sulfur, showing a factor of 2 enhancement in total sulfate aerosol number density at 30 km for an input of 3.0 t S d −1 . The input rate estimate of 1.0 t S d −1 suggests an enrichment of sodium relative to sulfur of 2.7 ± 1.5 and is consistent with a total cosmic dust input rate of 44 t d −1 .