Dust is an important component of both the physical and biological components of the earth system. Wind erosion can lead to the nutrient impoverishment of soils, and dust deposition can fertilize ocean, freshwater and terrestrial ecosystems. Dust also plays a crucial role in climate on glacial timescales and is one of the more uncertain components of the future climate forecasts. At the global scale, the largest sources of dust are the Sahara and Sahel deserts of Africa and the Gobi desert in Asia.
Results/Conclusions
Emissions of dust from the major global deserts can vary from year to year and are strongly influenced by climate variability. The global cycle of dust, driven by the large global dust sources, plays an important role in marine nutrient cycling as well as in nutrient deposition to some terrestrial settings. These large sources of dust are the primary focus of atmospheric modeling efforts and collectively, the major global deserts have an important (albeit uncertain) impact on global climate.In parallel to the global dust cycle, there are numerous smaller, regional deserts around the globe that also generate substantial amounts of dust and although the emission and deposition patters tend to occur at the continental scale, these smaller sources may play a very important, and underappreciated, role in terrestrial and freshwater biogeochemistry. For deserts in North and South America, there is increasing evidence that dust emission and deposition can also be affected by land use change with large 20th century increases in dust emission that coincide with agricultural intensification. Because soils provide the foundation for nutrient cycling in ecosystems, loss of soil from dryland regions has long-term implications for soil fertility and biogeochemical cycling. Conversely, dust deposition can be an important source of nutrients and alkalinity to downwind ecosystems, and regional dust cycles can play a role in continental climate change. In this talk, I will provide an overview of the global and regional dust cycle with a particular focus on recent changes to dust cycles and discussion of the ways in which dust emission and deposition could influence ecological processes.
