Black Carbon Reflects Extremely Efficient Aerosol Wet Removal in Monsoonal Convective Transport
Year: 2025
Authors: Berberich J., Jacoby S.A., Michailoudi G., Schwarz J.P., Viciani S., D’Amato F., Bianchini G., Barucci M., Campos T., Ullman K., Podolske J.R., Gurganus C., Smith W.P., Ueyama R., Honomichl S.B., Pan L.L., Woods S., Wienzierl B., Dollner M., Perring A.E.
Autors Affiliation: Colgate Univ, Dept Chem, Hamilton, NY 13346 USA; Univ Michigan, Dept Chem, Ann Arbor, MI USA; Univ Maryland, Dept Chem & Biochem, College Pk, MD USA; Univ Colorado Boulder, Cooperat Inst Res Environm Sci CIRES, 216 UCB, Boulder, CO 80309 USA; NOAA, Earth Syst Res Lab, Boulder, CO USA; CNR, Natl Inst Opt CNR INO, I-50019 Sesto Fiorentino, Italy; NSF Natl Ctr Atmospher Res, Atmospher Chem Observat & Modeling Lab, Boulder, CO USA; NASA, Ames Res Ctr, Moffett Field, CA USA; NSF Natl Ctr Atmospher Res, Earth Observing Lab, Boulder, CO USA; Univ Vienna, Fac Phys Aerosol Phys & Environm Phys, Vienna, Austria.
Abstract: Refractory black carbon (rBC) is a primary aerosol species, produced through incomplete combustion, that absorbs sunlight and contributes to positive radiative forcing. The overall climate effect of rBC depends on its spatial distribution and atmospheric lifetime, both of which are impacted by the efficiency with which rBC is transported or removed by convective systems. These processes are poorly constrained by observations. It is especially interesting to investigate rBC transport efficiency through the Asian Summer Monsoon (ASM) since this meteorological pattern delivers vast quantities of boundary layer air from Asia, where rBC emissions are high to the upper troposphere/lower stratosphere (UT/LS) where the lifetime of rBC is expected to be long. Here, we present in situ observations of rBC made during the Asian Summer Monsoon Chemistry and Climate Impact Project of summer, 2022. We use observed relationships between rBC and CO in ASM outflow to show that rBC is removed nearly completely (>98%) from uplifted air and that rBC concentrations in ASM outflow are statistically indistinguishable from the UT/LS background. We compare observed rBC and CO concentrations to those expected based on two chemical transport models and find that the models reproduce CO to within a factor of 2 at all altitudes whereas rBC is overpredicted by a factor of 20-100 at altitudes associated with ASM outflow. We find that the rBC particles in recently convected air have thinner coatings than those found in the UTLS background, suggesting transport of a small number of rBC particles that are negligible for concentration.
Journal/Review: JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
Volume: 130 (3) Pages from: e2024JD042692-1 to: e2024JD042692-1
More Information: The ACCLIP campaign was supported by NSF, NASA, and NOAA. The GV is managed and operated by NSF NCAR’s Earth Observing Laboratory. J.B., S.A.J., A.E.P., G.M., J.P.S., and C.G. acknowledge support from NOAA Earth’s Radiation Budget program, the NASA Upper Atmospheric Composition Program and NSF. J.B., S.A.J., and A.E.P also acknowledge the Colgate Research Council. T.C., The COLD2 deployment is funded by European Space Agency (ESA) contract QA4EO-ACCLIP. R.U. acknowledges the NASA Upper Atmosphere Composition Observations Program. W.P.S. was supported by grant NSF AGS-1853929. B.W. and M.D. were supported by NOAA, NASA and the University of Vienna. The authors are grateful to the GV and WB-57 pilots and ground crew and the Osan Air Base staff for their support of the project.KeyWords: black carbon; ACCLIP; convective transport; rBC; monsoon; UTLSDOI: 10.1029/2024JD042692