North African dust absorbs less solar radiation than estimated by models and remote-sensing retrievals

This is a Preprint and has not been peer reviewed. This is version 1 of this Preprint.

Add a Comment

You must log in to post a comment.


Comments

There are no comments or no comments have been made public for this article.

Downloads

Download Preprint

Authors

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

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. 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 world's dust. We find that 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. Additionally, similar factors contribute to an overestimation of AAOD retrieved by the ground-based Aerosol Robotic Network over North Africa. We conclude that the overestimation of simulated and retrieved dust absorption suggests substantial biases in current estimates of dust impacts on the Earth system, including a warm bias in dust radiative effects.

DOI

https://doi.org/10.31223/X5ZH21

Subjects

Atmospheric Sciences, Climate

Keywords

Dust, Shortwave Absorption, absorption aerosol optical depth, AERONET, climate models, climate

Dates

Published: 2022-10-17 07:22

License

CC BY Attribution 4.0 International

Additional Metadata

Conflict of interest statement:
None