Unveiling the deep-time Earth dust emissions: Modelling and Diagnosing control factors

Desert dust is a vital component of the Earth's climate system. The climate system regulates dust emission processes, such as sediment availability and wind entrainment, in various ways. Dust modulates the Earth's radiation balance, and wind-carried dust deposition provides essential nutrient iron to land and marine ecosystems.  While dust science is well-developed for the modern and the Quaternary (the last 2.6 Ma), little investigation has been done for the Earth's deep time.

Here, we present for the first time a continuous reconstruction of dust emissions throughout the Phanerozoic era (since 540 Ma ago), simulated by a newly developed dust emission model DUSTY, which is forced by the paleoclimate fields from the General Circulation Model HadCM3L. Our results show how dust emissions fluctuated over time with a stage-level resolution (approximately 5 Ma). We then diagnosed the controls of these fluctuations, highlighting that the non-vegetated area is the main contributor, which is controlled through precipitation levels. The ultimate dominating forcing is the paleogeography changes, whereas CO₂ plays a marginal role. We compare our results with sediment evidence and find good agreement. Finally, we present ongoing work investigating further how dust deposition might have impacted ocean production and biogeochemistry through deep-geologic time.