DustIron: Global mineral dust simulations with ECHAM-HAMMOZ for modern and last glacial maximum climate conditions

In this study, we present results of new mineral dust simulations performed with the model setup ECHAM-HAMMOZ. The simulations are part of the AWI project DustIron, a coupled data-model approach to investigate past changes of the Southern Hemisphere dust cycle and potential Southern Ocean iron fertilization as a result of atmospheric mineral dust / iron input.

The model setup consists of the latest atmospheric general circulation model release ECHAM6, coupled to the aerosol model HAM2.3 and the atmospheric chemistry model MOZ1.0. Our focus is on dust emission and deposition rates as well as the identification of key source and deposition areas in the Southern Hemisphere by sensitivity experiments for modern (1850 AD) and last glacial maximum (21 ka BP) climate conditions. The spatial patterns of the decadal mean of the simulated annual dust deposition agree well with recent CESM simulation results (Albani et al., 2016) for modern climate conditions. A comparison of the decadal mean of the total global annual dust emissions simulated with ECHAM-HAMMOZ (1361 Tg a^-1) to CESM (2785 Tg a^-1, Albani et al., 2019) shows that the model performs rather at the lower end concerning global dust emissions. The tendency to a slight underestimation of global annual mineral dust emissions, however, is in agreement with the model’s aerosol evaluation by Tegen et al. (2019).