By fitting a very simple atmospheric impurity model to high-resolution data on ice accumulation and contaminant f1uxes in the GISP2 ice core, we have estimated changes in the atmospheric concentrations of soluble major ions, insoluble particulates and 10Be during the transition from glacial to Holocene conditions. For many species, changes in concentration in the ice typically overestimate atmospheric changes, and changes in flux to the ice typically underestimate atmospheric changes, because times of increased atmospheric contaminant loading are also times of reduced snowfall. The model interpolates between the flux and concentration records by explicitly allowing [or wet- and dry- deposition processes. Compared to the warm Preboreal that followed, we estimate that the atmosphere over Greenland sampled b y snow accumulated during the Younger Dryas cold event contained on average four-seven times the insoluble particulates and n early seven times the soluble calcium derived from continental sources, and about three times the sea salt but only slightly more cosmogenic 10Be
