Modeling of dust-radiation interaction within the NASA GISS ModelE2.1.


In this seminar, Dr Vincenzo Obiso will present the latest advances about the modeling of dust-radiation interaction within the NASA GISS ModelE2.1.
The first part will focus on the coupling of radiation calculations to the spatially and temporally varying mineral composition of dust aerosols. Dust optical properties are calculated accounting for composition at ultraviolet-visible wavelengths using a semi-empirical approach based on measured relationships of dust imaginary refractive index to the content of iron oxide minerals. With respect to our default unspeciated dust, the coupled mineral model calculates lower absorption, along with a larger spatio-temporal variability of dust single scattering albedo, which together lead to a better agreement with dust retrievals from AERONET. This results emphasize the cooling effect of dust, while highlighting the need for more accurate measurements of soil mineral abundances.
In the second part, he will present an assessment of the impact of dust particle non-sphericity on the direct radiative effect by dust in this model. Tri-axial ellipsoids are assumed, following distributions of axis ratios taken from measurements, as a reasonable compromise between natural shape complexity and suitability for model applications. This analysis confirms that non-sphericity strongly increases the extinction efficiency of dust, which allows a reconciliation of our global-annual mean dust optical depth with a semi-observational constraint. The shape-induced extinction amplification implies a potentially critical effect on the regional direct radiative effect by dust and its climate impact.
In the last part, preliminary results about the effect of mineral-radiation interactions upon precipitation and the hydrological cycle will be presented.

14 June 2023


Presented by

Vincenzo Obiso

Event type



13:00 - 14:00 UTC




1 h

Barcelona Dust Regional Center