First use of CAMAERA results in CAMS

In the framework of CAMAERA WP5 activities, a new dust emission scheme, adapted from the System for Integrated modeLling of Atmospheric coMposition (SILAM) model operated by the Finnish Meteorological Institute, is being tested in the global model IFS-COMPO of the Copernicus Atmosphere Monitoring Service (CAMS). This new dust emission scheme has a very simple formulation and, as external input, uses roughness length derived from remote sensing data. The impact of this new dust emission scheme on the simulated dust life cycle is being evaluated against a wide range of observational datasets. For most metrics, the use of this CAMAERA development is improving the skill of model to forecast dust-related products as shown on the figures below.
As a consequence, it has been decided to use this new dust emission scheme in a task carried out within the CAMS2_35 project (global CAMS model development), coordinated by HYGEOS and KNMI, namely the production of a dataset of simulated mineralogical composition of dust. This dataset will include 12 mineralogical species (Calcite, Chlorite, Dolomite, Feldspar, Goethite, Gypsum, Hematite, Illite, Kaolinite, Montmorillonite, Quartz and Vermiculite) over the period 2003-2025. The dataset is in the course of being produced, using a modified, experimental version of IFS-COMPO which represents dust mineralogy together with the new dust emission scheme. Inputs on the mineralogy of the soils are provided by the NASA Earth Surface Mineral Dust Source Investigation (EMIT) mission products.


Density scatterplot of simulated (FC) versus observed (OB) Aerosol Optical Depth (AOD) at 500nm, for year 2019, over AERONET stations primarily impacted by desert dust. Only observations with an Ångstrom Exponent below 0.3, representative of pure dust situations, are taken into account. The simulations don’t include data assimilation and use IFS-COMPO cycle 49R1 ; the operational dust emission scheme (REF) is used on the left, the new CAMAERA dust emission scheme (NEW) is used on the right.
This dataset of simulated dust mineralogy can be used for many purposes. For example, ocean biogeochemistry is impacted by the concentration and deposition of atmospheric iron, largely dominated by dust iron. An evaluation of simulated iron surface concentration in 2019 against climatological observations is shown in the figure below. A better knowledge of dust mineralogy also allows a better understanding of the radiative impact of dust on the atmosphere. The mineralogical species have very different radiative properties ands in particular, the iron oxides (hematite and goethite) are much more absorbing than the other species. Some species are hydrophilic (montmorillonite) while most of the others are not. A more detailed representation of dust mineralogy will also help improve our understanding and, in fine, the representation of dust in global atmospheric composition models.
The new dust emission scheme that has been developed in CAMAERA will be proposed for operational implementation for global CAMS production system in the near future.

Simulated (2019 average) surface concentration of iron in ng/m2 compared to climatological observations (circles).