02-26E

A mechanism of HCl and water co-adsorption at ice surface is studied within a simple two-component model, treated in the mean field approximation. It is shown that a realistic choice of the HCl-water interaction (about the hydrogen bond strength) leads to a remarkable increase of HCL uptake in comparison to the case when HCl is adsorbed alone. Based on the model we are able to recover the experimental results for HCl on ice at stratospheric conditions.