Journal article
Large Particle Size and Thick Coating Influence Pyrocumulonimbus Smoke Radiative Forcing and Stratospheric Warming: Insights From the 2019–2020 Australian Megafires
Geophysical research letters, Vol.53(10), e2025GL119099
05/28/2026
DOI: 10.1029/2025GL119099
Appears in UI Libraries Support Open Access
Abstract
Large particle size and thick coatings have been detected in pyrocumulonimbus (pyroCb) smoke injected into the lower stratosphere, enhancing both extinction and absorption of smoke. Here, we quantified how particle size and coating, via internal mixing of non‐absorbing species on black carbon, influence pyroCb smoke radiative forcing and stratospheric heating using core‐shell Mie calculations coupled with chemical transport and radiative transfer models. Airborne measurements indicate a number median radius of 0.25 μm for days‐old pyroCb smoke, larger than typical lower tropospheric smoke. This larger size approximately doubles aerosol extinction and enhances shortwave radiative forcing at the top of the atmosphere by 35%–60%, more consistent with satellite‐observed radiative fluxes following 2019–2020 Australian pyroCb event. Coating enhances stratospheric heating by 1–1.5 K, twice the enhancement caused by larger particle size, yielding better agreement with stratospheric temperature anomaly observed from satellite during the first 3 months after injection.
Details
- Title: Subtitle
- Large Particle Size and Thick Coating Influence Pyrocumulonimbus Smoke Radiative Forcing and Stratospheric Warming: Insights From the 2019–2020 Australian Megafires
- Creators
- Xi Chen - University of Iowa, Iowa Technology InstituteJun Wang - University of IowaDavid A Peterson - United States Naval Research LaboratoryYaowei Li - Harvard UniversityWilliam Julstrom - University of IowaFrank N Keutsch - Planetary Science InstituteJohn Dykema - Harvard University
- Resource Type
- Journal article
- Publication Details
- Geophysical research letters, Vol.53(10), e2025GL119099
- DOI
- 10.1029/2025GL119099
- ISSN
- 0094-8276
- eISSN
- 1944-8007
- Publisher
- Wiley
- Grant note
- NOAA Climate & Global Change Postdoctoral Fellowship Program: NA23OAR4310383B National Aeronautics and Space Administration: 80HQTR21T0099, 80NSSC19K0326 NASA Stratospheric Aerosol and Gas Experiment III/International Space Station program: 80NSSC21K1199, 80NSSC25K7183
This work was supported by the funding from National Aeronautics and Space Administration (NASA), Stratospheric Aerosol and Gas Experiment III/International Space Station program (SAGE III/ISS, Grant 80NSSC21K1199 and 80NSSC25K7183). We acknowledge the NASA satellite missions, including the OMPS-LP, SAGE III/ISS, and MLS teams, for providing stratospheric gases and aerosol products. Support for D. P. was provided by the U. S. Naval Research Laboratory's 6.2 Base Program, NASA's Modeling, Analysis, and Prediction (MAP) Program (80HQTR21T0099), FireSense Program, and INjected Smoke and PYRocumulonimbus Experiment (INSPYRE). Y.L., F.K., and J.D. acknowledge support from NASA under DCOTSS award (80NSSC19K0326). Y. L. also acknowledges partial support from the NOAA Climate & Global Change Postdoctoral Fellowship Program (award NA23OAR4310383B).
- Language
- English
- Date published
- 05/28/2026
- Academic Unit
- Electrical and Computer Engineering; Civil and Environmental Engineering; Iowa Technology Institute; Physics and Astronomy; Chemical and Biochemical Engineering
- Record Identifier
- 9985164290202771
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