A big unknown in the climate impact of atmospheric aerosol: Mineral soil dust

Martina Klose

Mineral soil dust is the most abundant aerosol type in terms of global mass. Soil dust is mainly emitted from arid and semi-arid regions, but can in principle be emitted from any uncovered dry soil surface under windy conditions, e.g. from agricultural fields. Mineral dust has important impacts on climate, air quality and health, road and air traffic, economy, and not least photovoltaic power generation in many areas of the world including Europe. The amount, particle-size distribution, shape, and composition of dust aerosol determine largely its climate impact. Recent studies have shown that airborne dust particles can be larger than previously thought and observations revealed that even giant dust particles (> 20 µm) can be transported over long distances. A misrepresentation of dust-aerosol size leads to biases in estimates of direct and indirect (i.e. related to clouds) dust radiative effects. Here I present recent advances in the quantification of the dust cycle and its impacts. I focus on dust emission, dust composition (mineralogy), and the impact of land-surface properties, in particular surface roughness in arid and semi-arid regions, including anthropogenic (agricultural) sources. I conclude with an outlook on planned research within the new Helmholtz Young Investigator Group “Mineral Dust” at KIT IMK-TRO.