Joint influence of surface erosion and high-latitude ice-sheet extent on Asian dust cycle during the last glacial maximum

Abstract

AbstractThe dust cycle plays an important role in the long-term evolution of the climate and environment. In this paper, an improved climate model including aerosol processes was used to carry out a set of sensitivity experiments and comparative analyses of the effects of high-latitude ice-sheet extent and abnormal dust erosion, as well as Earth’s orbital parameters and atmospheric greenhouse gas content, on dust activities during the last glacial maximum. The comparative analysis found that incorporating the abnormal surface erosion factor alone could increase dust emissions by 2.77-fold and 3.77-fold of the present-day global and Asian dust emissions, respectively. The high-latitude ice-sheet factor caused global dust emissions to increase by 1.25-fold that of the present day. Sensitivity experiments showed that increased surface erosion in Asia during the last glacial maximum made the greatest contribution to the increased dust emissions in Asia, followed by the high-latitude ice-sheet factor, while the contributions of the greenhouse gas content and orbital parameters were relatively weak. Strong dust emissions during the glacial period were therefore not only dependent on the development of the high-latitude ice sheets but were strongly associated with the underlying surface characteristics of local dust source regions.