Project Info

Aeolian processes on geological time scales are closely related both to climate change and bio-ecological evolution. In the Atacama Desert where fluvial/glacial processes are non-existent, aeolian processes virtually govern the evolution of the land surface and the proxies of planetary geomorphology.

On the other hand, land-surface conditions (e.g. soil wetness, vegetation cover and surface crust) strongly influence the rate of aeolian transport. Bacteria and fungi not only transform minerals to soil, but also control surface crust formation and evolution, while on the other hand, wind erosion or deposition rates may prohibit and suppress the growth of biogenic crusts and vegetation. Also vegetation profoundly affects biogenic crust and aeolian aerodynamics. Thus, climatic, aeolian and bio-ecological processes have tightly coupled feedbacks which are key to characterizing the tipping points between biotic and abiotic Earth surface systems, establishing long-term terrestrial climatic records and estimating the rates of Earth surface and biological evolution. The central task of A03 is to develop a conceptual framework for investigation of the interactions between aeolian and biological processes in the Atacama Desert and to develop for the first time a numerical system for modelling how such interactions on geological time scales. New aeolian and biogenic modules will be developed and integrated in the existing dust modelling system that has been under development at the University of Cologne over the past years. A major theoretical and technical challenge is also how to run a dynamic model over a period of 106 years with a resolution high enough to represent aeolian transport in the Atacama. In A03, we propose a statistical-dynamic downscaling approach, i.e., the probabilistic distribution of climate will be determined and for each climate mode, aeolian transport will be simulated. The results will then be combined statistically based on the relative frequency of the climate modes. The main outcomes of the project include (1) a basic concept and model framework which allow the integration of understanding on aeolian-biologic processes, and (2) preliminary simulations of aeolian-biological interactions in the Atacama Desert on geological time scales.