2020 Chapters (Layout Features)

Ground-Air Interface: The Loess Sequences, Markers of Atmospheric Circulation

Rousseau, Denis-Didier; Hatté, Christine

Atmospheric circulation is responsible for the rapid distribution of heat and moisture across the Earth and hence determines our weather and regional climate, today and in the past. During past climate cycles, the atmosphere has been much more dustier, except during the interglacials, inducing uncertainties about the impact of mineral aerosols on the past climate dynamics. There are abundant traces of the combination of past atmospheric dynamics and paleodust cycle such as eolian mineral material transported and deposited in terrestrial archives as loess. Records from loess deposits consistently suggest that atmospheric dynamics was highly variable, during the past climate cycles, much more than presently where the only sources of dust are the major deserts. In this chapter we explained the four main categories of parameters allowing to identify loess deposits as reliable markers for past air circulation.