  An earlier study evaluating the dust life cycle in the Energy Exascale Earth
System Model (E3SM) Atmosphere Model version 1 (EAMv1) has revealed that the
simulated global mean dust lifetime is substantially shorter when higher
vertical resolution is used, primarily due to significant strengthening of dust
dry removal in source regions. This paper demonstrates that the sequential
splitting of aerosol emissions, dry removal, and turbulent mixing in the
model's time integration loop, especially the calculation of dry removal after
surface emissions and before turbulent mixing, is the primary reason for the
vertical resolution sensitivity reported in that earlier study. Based on this
reasoning, we propose a simple revision to the numerical process coupling
scheme, which moves the application of the surface emissions to after dry
removal and before turbulent mixing. The revised scheme allows newly emitted
particles to be transported aloft by turbulence before being removed from the
atmosphere, and hence better resembles the dust life cycle in the real world.
Sensitivity experiments are conducted and analyzed to evaluate the impact of
the revised coupling on the simulated aerosol climatology in EAMv1.
