We consider two models for the etching processes using numerical simulations based on cellular-automata discrete-lattice approach. In one model we use a uniform etching probability for each surface site. In another model the etching probability at a given site depends on the local environment of this site. In contrast to the first model we have now a non-local description of the surface evolution. It is natural to consider the following question: is this non-locality sufficient to induce new physics? To answer this question is the main goal of the paper. We show that there exists an equivalence between the two models. This means that the non-local model gives results similar to the local one provided we use an effective value of the etching probability.

It is shown that the adsorption of HCl molecules at the surface of ice increases, if the HCl binding energy increases with the distortion amplitude of the oxygen sites of ice. At the same time, the adsorption stimulates an increase of the Lindemann parameter for the ice lattice, driving its melting at temperatures (T = 190 K) relevant to the polar stratosphere. Similar effects take place when the lateral interaction between HCl molecules becomes more attractive due to the coupling through the ice lattice.