Document Type
Article
Publication Date
11-28-2024
Department
Department of Chemistry
Abstract
Wildfires emit solid-state strongly absorptive brown carbon (solid S-BrC, commonly known as tar ball), critical to Earth's radiation budget and climate, but their highly variable light absorption properties are typically not accounted for in climate models. Here, we show that from a Pacific Northwest wildfire, over 90% of particles are solid S-BrC with a mean refractive index of 1.49 + 0.056i at 550 nm. Model sensitivity studies show refractive index variation can cause a ~200% difference in regional absorption aerosol optical depth. We show that ~50% of solid S-BrC particles from this sample uptake water above 97% relative humidity. We hypothesize these results from a hygroscopic organic coating, potentially facilitating solid S-BrC as nuclei for cloud droplets. This water uptake doubles absorption at 550 nm and the organic coating on solid S-BrC can lead to even higher absorption enhancements than water. Incorporating solid S-BrC and water interactions should improve Earth's radiation budget predictions.
Publication Title
Nature communications
Recommended Citation
Cheng, Z.,
Shrivastava, M.,
Ijaz, A.,
Veghte, D.,
Vandergrift, G. W.,
Tseng, K.,
Lata, N. N.,
Kew, W.,
Suski, K.,
Weis, J.,
Kulkarni, G.,
Berg, L. K.,
Fast, J. D.,
Kovarik, L.,
Mazzoleni, L.,
Zelenyuk, A.,
&
China, S.
(2024).
Enhanced light absorption for solid-state brown carbon from wildfires due to organic and water coatings.
Nature communications,
15(1), 10326.
http://doi.org/10.1038/s41467-024-54506-5
Retrieved from: https://digitalcommons.mtu.edu/michigantech-p2/1251
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Version
Publisher's PDF
Publisher's Statement
© Battelle Memorial Institute and Lynn Mazzoleni. Parts of this work were authored by US Federal Government authors and are not under copyright protection in the US; foreign copyright protection may apply 2024.