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  • Dust Constraints from joint Observational-Modelling-experiMental analysis (DustCOMM): comparison with measurements and model simulations
Title: Dust Constraints from joint Observational-Modelling-experiMental analysis (DustCOMM): comparison with measurements and model simulations
Abstract. Mineral dust is the most abundant aerosol species by massin the atmosphere, and it impacts global climate, biogeochemistry, and humanhealth. Understanding these varied impacts on the Earth system requiresaccurate knowledge of dust abundance, size, and optical properties, and howthey vary in space and time. However, current global models show substantialbiases against measurements of these dust properties. For instance, recentstudies suggest that atmospheric dust is substantially coarser and moreaspherical than accounted for in models, leading to persistent biases inmodelled impacts of dust on the Earth system. Here, we facilitate moreaccurate constraints on dust impacts by developing a new dataset: DustConstraints from joint Observational-Modelling-experiMental analysis(DustCOMM). This dataset combines an ensemble of global model simulationswith observational and experimental constraints on dust size distributionand shape to obtain more accurate constraints on three-dimensional (3-D)atmospheric dust properties than is possible from global model simulationsalone. Specifically, we present annual and seasonal climatologies of the 3-Ddust size distribution, 3-D dust mass extinction efficiency at 550 nm, andtwo-dimensional (2-D) atmospheric dust loading. Comparisons with independentmeasurements taken over several locations, heights, and seasons show thatDustCOMM estimates consistently outperform conventional global modelsimulations. In particular, DustCOMM achieves a substantial reduction in thebias relative to measured dust size distributions in the 0.5–20 µmdiameter range. Furthermore, DustCOMM reproduces measurements of dust massextinction efficiency to almost within the experimental uncertainties,whereas global models generally overestimate the mass extinction efficiency.DustCOMM thus provides more accurate constraints on 3-D dust properties, andas such can be used to improve global models or serve as an alternative toglobal model simulations in constraining dust impacts on the Earth system.  more » « less
Award ID(s):
1856389
PAR ID:
10166140
Author(s) / Creator(s):
; ; ; ; ; ;
Date Published:
Journal Name:
Atmospheric Chemistry and Physics
Volume:
20
Issue:
2
ISSN:
1680-7324
Page Range / eLocation ID:
829 to 863
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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