This Working Group aimed to better understand the role of mineral aerosol (“dust”) in the Earth System. Dust links terrestrial processes (deflation from unvegetated surfaces in suitable geomorphic settings) to radiative forcing (as a heterogeneous absorbing aerosol) to atmospheric chemistry (as a predominantly basic material that reacts with acidic aerosols, e.g. sulphate), marine ecosystems and atmospheric CO2 content (as a principal supplier of iron, a limiting micronutrient, to large areas of the ocean and thus a regulator of the strength of the biological pump). Large changes in atmospheric dust concentration between glacial and interglacial stages have been implicated in the natural cycle of changes in atmospheric CO2 concentration. Dust in large quantities is also a geomorphic and pedogenic agent (in the form of loess), and a hazard to health and transport; while acting in a beneficial way over geologic time scales as the principal supply of phosphorus, the limiting nutrient for terrestrial ecosystem productivity in extensive unglaciated regions of the Earth.
Dust was the subject of an earlier IGBP Fast Track Initiative, which led to a synthesis article in Science by Tim Jickells et al. The WG built on this earlier synthesis work to develop a deeper understanding of the climatic, geomorphic and biotic processes determining dust emissions, the radiative and chemical properties of dust from different provenances, and the implications of atmospheric dust loading for climate and ecosystems over glacial-interglacial and contemporary time scales.
Leader: Barbara Maher (Lancaster)
QUEST links: Theme 1 (all projects), Theme 2 (DESIRE)