Observations suggest that North African dust absorbs less solar radiation than models estimate

Journal Article · 16 May 2023 · Communications Earth & Environment

DOI: https://doi.org/10.1038/s43247-023-00825-2 · OSTI ID:1974089

Adebiyi, Adeyemi A. ; Huang, Yue; Samset, Bjørn H. ; Kok, Jasper F.

Abstract Desert dust accounts for a large fraction of shortwave radiation absorbed by aerosols, which adds to the climate warming produced by greenhouse gases. However, it remains uncertain exactly how much shortwave radiation dust absorbs. Here, we leverage in-situ measurements of dust single-scattering albedo to constrain absorption at mid-visible wavelength by North African dust, which accounts for approximately half of the global dust. We find that climate and chemical transport models overestimate North African dust absorption aerosol optical depth (AAOD) by up to a factor of two. This occurs primarily because models overestimate the dust imaginary refractive index, the effect of which is partially masked by an underestimation of large dust particles. Similar factors might contribute to an overestimation of AAOD retrieved by the Aerosol Robotic Network, which is commonly used to evaluate climate and chemical transport models. The overestimation of dust absorption by models could lead to substantial biases in simulated dust impacts on the Earth system, including warm biases in dust radiative effects.

• Research Organization: Univ. of California, Merced, CA (United States)
• Sponsoring Organization: USDOE; USDOE Office of Science (SC)
• Grant/Contract Number: SC0023033
• OSTI ID: 1974089
• Journal Information: Communications Earth & Environment, Journal Name: Communications Earth & Environment Journal Issue: 1 Vol. 4; ISSN 2662-4435
• Publisher: Nature Publishing GroupCopyright Statement
• Country of Publication: United Kingdom
• Language: English