The variations of the metabolism of the glaciers and the polar ice sheets reflect the climate fluctuations. On the yearly time scale, these fluctuations result in variations of the mass balance of the glacier. The bibliographical search of mass balance series produced some 60 long series of measurements on glaciers, distributed on the different mountainous ranges of the north hemisphere and some 60 sites on the Greenland ice sheet. From this data set, a statistical analysis made it possible to determine the spatial and temporal distribution of the series, as well as to better understand the relation glacier-climate for various scales ranging from that of a glacier , to that of a massif or a continent. On the glacier, the history of balances can be sometimes very different from one point to the other because of the difference in sensibility of the balance versus height. This study outlines the disparities linked to the accumulation data. Linear mass balance model distribution along altitude is seldom adapted to describe mass balance variations on a glacier. On the other hand, coherence between different series can be sometimes very high when comparing glaciers mass balance inside a mountainous area as the Alps or Scandinavia. The similarities however are dependent on the period examined, probably because of the more important role of the winter accumulation. On other mountainous area such as the western Cordillera of North America or the Greenland accumulation area, mass balance coherence are not so pronounced even though distances are smaller than those of the two previous cases. For this last one, analyses show that it is difficult to identify a coherent annual signal among the measurement noise. In order to detail glacier responses to past and present climate variations, meteorological data and North Atlantic Oscillation are finally examined in relation to mass balance fluctuations. Temperature, precipitation and mass balance changes on the north Atlantic area seem to be linked to decenal fluctuations of the North Atlantic Oscillation system (NAO).
Analyse statistique des distributions des séries de bilans de masse des glaciers alpins et des calottes polaires de l'hémisphère nord