Stable water isotope measured on Col du Dôme and Colle Gnifetti ice cores

We address from a glaciological perspective the specific conditions of Alpine drilling sites and, in particular, the role of depositional noise.

Thereby, we refer to two major drilling areas (located in the summit range of Monte Rosa and Mt Blanc massif, respectively) which largely differ in their snow accumulation rate and, hence, in their accessible time scale. A simple scheme considering the seasonality of both, the precipitation-borne signal and the snow erosion-controlled net accumulation rate is presented. It shows that water isotope trends are generally more sensitive to distortion by a seasonality effect than recent snow impurities trends, although the influence of a given seasonal accumulation rate cycle on the mean levels of water isotopes and impurities is similar.