The adsorbate dynamics during simultaneous action of desorption and lateral
adsorbate diffusion is studied in a simple lattice-gas model by kinetic Monte
Carlo simulations. It is found that the action of the coverage-conserving
diffusion process during the course of the desorption has two distinct,
competing effects: a general acceleration of the desorption process, and a
coarsening of the adsorbate configuration through Ostwald ripening. The balance
between these two effects is governed by the structure of the adsorbate layer
at the beginning of the desorption process