Titre

Influence of climate change over the 20th Century on four French glacier mass balances

Année de publication

2002

Source

Journal of Geophysical Research: Atmospheres 107 ACL 4-1 ACL 4-12 D19

ISSN
0148-0227
Résumé

Winter and summer mass balance measurements from four French glaciers have been used to assess the sensitivity of mass balance to climatic fluctuations. The sensitivity of summer ablation to temperature is maximum in low‐elevation zones (1.4 m water equivalent (w.e.) °C−1 at 1800 m above sea level (asl)) and decreases with altitude (0.5 m w.e. °C−1 at 2900 m asl). As a consequence, the sensitivity of equilibrium line altitude to temperature is 60–70 m °C−1. This is half the value previously reported in the literature, implying that alpine glacier retreat scenarios for the 21st Century have been largely overestimated. Winter accumulation can be as high as 3 times the amount of precipitation recorded downvalley. These relationships between mass balance and meteorological data were then used to reconstruct the mass balances of these four glaciers back to 1907 using old maps and photogrammetric measurements. Model sensitivity analysis shows that a 25–30% increase in precipitation would compensate a 1°C temperature rise for the mass balances of glaciers. From these results the 20th Century may be divided into four periods: two steady state periods, 1907–1941 and 1954–1981, during which the mass of glaciers remained almost constant, and two deficit periods, 1942–1953 and 1982–1999, marked by a sharp reduction in glacier mass. Regarding mean ablation at 2800 m asl, a 22 W m−2 increase in energy balance is required to explain the ablation difference between the two most recent periods, 1954–1981 and 1982–1999. According to the energy balance analysis the increase in air temperature explains more than 60% of this ablation rise.

Type de publication
  • journal
Type de document
  • article
Classification
 
Classification - Inist-CNRS
    Classification - Scopus
    • 1 - Physical Sciences
    • 2 - Earth and Planetary Sciences
    • 3 - Palaeontology
    • 3 - Space and Planetary Science
    • 3 - Earth and Planetary Sciences (miscellaneous)
    • 3 - Atmospheric Science
    • 3 - Earth-Surface Processes
    • 3 - Geochemistry and Petrology
    • 1 - Life Sciences
    • 2 - Agricultural and Biological Sciences
    • 3 - Soil Science
    • 2 - Environmental Science
    • 3 - Water Science and Technology
    • 3 - Ecology
    • 3 - Aquatic Science
    • 3 - Forestry
    • 3 - Oceanography
    • 3 - Geophysics
    Classification - Science Metrix
    • 1 - natural sciences
    • 2 - earth & environmental sciences
    • 3 - meteorology & atmospheric sciences
    Classification - Clarivate Analytics (Subject Category)
    • 1 - science
    • 2 - geosciences, multidisciplinary
    Termes extraits

    glacier; precipitation; sorlin; ablation; albedo; glaciol; saint sorlin glacier; argentiere; mass balance; glace; cpdd; french glacier mass balances; oerlemans; vallon; meteorological data; energy balance; fluctuation; sarennes; braithwaite; climatic; chamonix; saint sorlin; besse; september; alpine; summer mass balance; winter mass balance; snow ablation; haeberli; zhang; winter precipitation; gebroulaz; summer mass balances; french glaciers; total ablation; mass balance sensitivity; mass balances; valley precipitation; french alps; accumulation zone; ablation period; winter accumulation; rock debris; climate change; ablation measurements; winter snow; swiss glaciers; mass balance fluctuations; other glaciers; temperature increase; energy fluxes; field measurements; previous study; temperature rise; glace glaciers; other hand; century figure; surface albedo; sarennes glacier; alps; meteorological; elevation; altitude; ablation values; ablation rise; equilibrium line; summer ablation; previous studies; strong correlation; summer temperature; general trend; unpublished data; argentiere glacier; temperature gradient; aerial photographs; annual mass balance; ablation increase; energy difference; photogrammetric measurements; topographic measurements; winter mass balances; summer albedo; heat exchange; linear relationship; large elevation range; temperature decreases; winter snow layer; summer value; ablation area; summer mass balance measurements; large uncertainties; present study; entire surface area; ablation difference; energy balance analysis; recherche scientifique; summer mass balance data; observation network; positive factor; glacier mass balances; elevation regions; summer precipitation; albedo pattern; meteorological stations; regression coefficients; glace glacier; equilibrium line altitude; observation elevation; climatic fluctuations; parameter sets; alpine glaciers; ablation zone; temperate glaciers; drill cores; valley winter precipitation; same time intervals; gebroulaz glacier; chamonix precipitation; large difference; winter valley precipitation; recent geodetic measurements; large triangles; observation site; small triangles; alpine glacier retreat scenarios; solid line; last period; ablation variations; accumulation rate; ablation rate; climatic variations; meteorological station; ablation periods; meteo france data; century table; volume variations; surface energy balance; long period; outgoing longwave radiation; wave radiation; large increase; model sensitivity analysis; possible contribution; sensible heat flux; glacier surface; climatic change; large dispersion; annual cycle; european alps; temperature changes; lapse rate

    Entité nommée
     
    Entité nommée - Emplacement géographique
    • Switzerland
    • Grenoble
    • Austria
    • Saint Sorlin
    • France
    • Lyon
    Entité nommée - Organisme
    • IGN
    • French National Geographic Institute
    • American Geophysical Union
    Entité nommée - Personne
    Patrick Wagnon; Winter Precipitation; J. Geophys; Alps; La Casiniere; Service; Emmanuel Le Meur; Altitude; Mass Balance; C. Vallot; C. Vincent; Martin; Mean; La Batiaz
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