Impact of atmospheric dust emission schemes on dust production and concentration over the Arabian Peninsula

This study examines the impact of two of the most advanced dust emission schemes on the predictions of the weather research and forecasting model with chemistry (WRF-Chem) over the Middle East during a summer time period. Results show significant differences between the two simulations in the spatial distribution of dust emissions as well as in their size-resolved mass discretization. The AFWA scheme simulation predicts 30 % higher dust emission fluxes than the S11 module over the Arabian Peninsula (6.7 μg m⁻² s⁻¹ compared to 4.5 μg m⁻² s⁻¹, respectively). In the S11 simulation 70 % of the emitted dust is in the 10–20 μm size range while the AFWA simulation assigns 50 % of dust emitted particles in the 6–12 μm size section. Both simulations reproduce the majority of the ambient PM₁₀ data (more than 70 %) within a factor of two. However, the S11 simulation predicts, on average, 50 % lower PM₁₀ concentrations compared to AFWA over the high resolution (2 × 2 km²) domain of Qatar. Previous applications of WRF-Chem may have substantially overestimated the simulated dust in this region.