Environmental & Climate Sciences Department Seminar

Dust aerosols are soil particles that are mobilized through wind erosion. They alter the energy and water cycles of the atmosphere through a combination of radiative and microphysical effects, while providing clues to the circulation of past climates. These effects depend upon composition in addition to particle size and shape. Here, we describe modeling of dust aerosol composition based on the content of the soil within dust source regions. These calculations are computationally expensive; it remains unknown whether regional variations in composition need to be considered to calculate the climate effect of dust, or alternatively, whether models can approximate dust aerosol composition as globally uniform. Resolution of this question may depend upon the radiative effect of coarse and super-coarse dust particles whose concentration is systematically underestimated by models. We will discuss sources of uncertainty in our calculations of aerosol size and composition, and the implications for whether regional variations in aerosol composition are crucial for calculating the dust effect upon climate.