Sun photometric dust optical properties and comparison with the Metal-WRF model

Trainer: Stavros Solomos and Ilias Fountoulakis

Introduction: Mediterranean countries are significantly affected by dust originating from North Africa and/or Middle
East. Depending on its origin (i.e., soil composition at the source), dust composition varies. Dust properties can
change further while it is traveling due to mixing with aerosols of other types (i.e., polluted aerosols) and/or
hygroscopic growth. The size, shape, and chemical composition of dust define its optical properties and subsequently
its impact on the solar radiation that reaches the Earth surface. Nevertheless, uncertainties in the estimates of the
radiative effects of dust in models and satellite algorithms are still large.

Idea: The idea is to use measurements of aerosol optical properties from different AERONET stations located at
Mediterranean and central European countries to investigate how dust optical properties change depending on its
origin and throughout its travel, and at which extent the METAL-WRF model can capture such changes. Furthermore,
we will try to quantify the effect of changing optical properties on dust radiative effects and solar energy production.


1. Find 5-6 intense dust events that happened in the last 10 years where dust originated from areas with different
soil composition. We will use satellite data (e.g., from IASI) to identify events that have affected at least 3-4
AERONET stations at relatively large distances from each other to follow the plume evolution.
2. Use the METAL-WRF model to determine the origin, the trajectories and the composition of dust for the different
events and compare the findings of the model with the satellite information.
3. Investigate the changes in the optical/physical properties of dust (SSA, Angstrom, size distribution) with
respect to its source and the traveling path using data from different stations for the selected events. Try to
explain the differences/similarities.
4. Estimate the optical properties of dust based on the composition of the dust mixture as described by
METAL-WRF and compare with AERONET and the chosen satellite products.
5. Compare the theoretical (WRF-CHEM) and measured optical properties and estimate the impact of using
different optical properties on the simulations of SSR. Estimate and analyze the differences in SSR
attenuation and solar energy losses with respect to the origin and the path of dust.
6. Incorporate any other interesting ideas from the people who will work on the topic.

Goal:Study the optical properties and the radiative effects of dust with respect to its origin and path and evaluate
the potential of the METAL-WRF to model dust optical properties. An abstract can be submitted to the EMS2024
Harmonia session and, depending on the results, a paper can be submitted to a peer reviewed journal.