WRF-Chem Sensitivity in an Saharan Dust Event

The Saharan dust event that occurred between June 20th and 30th 2012 influenced atmospheric radiative properties over NW Africa, Iberian Peninsula and Western Mediterranean basin, extending to France and Southern England. This event is well documented in satellite imagery, as well as air quality stations over Iberian Peninsula and AERONET NASA network.

According to MODIS satellite images, few fire hot spots were sensed over Iberian Peninsula during this period, making this event an opportunity to study the influence of dust aerosol in the atmosphere during summer time (ie, excluding the influence of major wildfires usually occurring over Portugal).

The WRF-Chem model was run on online mode featuring the CBMZ chemical MOSAIC aerosol mechanisms including the aerosol direct and indirect effects. A parent domain with 18 km horizontal resolution was used, covering Europe and North Africa. In order to assess the performance of the simulations, the results were compared with CALIPSO LIDAR data and AERLINET ground LIDAR station data.

Simulations show that the model is able to simulate the higher level dust aerosol transport. When comparing model results to observed vertical profiles it becomes evident that while being able to reproduce the more coarse features, the model is unable to identify the smaller-scale details.