Abstract. We have developed an original method coupling particle induced X ray emission and scanning electron microscope/X ray dispersive analysis in order to characterize the partitioning of Fe, Ca, K, and S between the soluble and the insoluble phases in wind-blown deposits in the Greenland ice. We applied this technique to several sections of the Greenland Ice Core Project ice core. We found that the dominant fraction (from 25 to 100%) of Ca and S deposited in Greenland is soluble, while the proportion of soluble material is lower for K and Fe (between 10 and 80%). For all elements the distribution between soluble and insoluble material varies according to the ice-core depth. The distribution appears to be linked to either meteorological factors, such as temperature or p H of the precipitation (in the case of Ca or S), or the alterability of the mineral assemblages found in the ice (in the case of Fe and K). The fraction of soluble material is therefore linked to the characteristics of source origin (S is predominantly emitted in very soluble forms) and to the dissolution of certain minerals (such as calcium carbonate or Fe-oxides) during transport in the atmosphere. The dynamics of alteration processes is, however, still uncertain, especially for K-containing minerals.

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Simulations of emitted plume dispersion in atmosphere performed by means of different models are compared: the study evaluates the capabilities of gaussian and lagrangian models in simulating pollutant plume dispersion in low wind conditions

107 samples from the first 581 m of the EPICA ice core, Dome C, East Antarctica, representing a 27000 year record, were analysed by the PIXE technique. The concentrations of several elements (Na, Mg, Al, Si, S, Cl, K, Ca, Ti, Mn, Fe) were determined in the insoluble particles, collected by filtration from the melted ice samples. The average elemental ratios for Holocene and LGM are in agreement with continental crust values. The element depositional fluxes, evaluated from PIXE concentration data by means of the EPICA ice accumulation rate, are smaller in the Holocene than during Glacial times, confirming the differences in dust loads in the atmosphere during the contrasting climatic conditions. In Holocene, the fraction of the insoluble particle mass (estimated as the sum of the measured element oxides) agrees well with the total dust mass as determined from Coulter Counter measurements, but during the LGM the particle counting shows a larger dust mass.

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