Little Ice Age climate reconstruction from ensemble reanalysis of Alpine glacier fluctuations

• Main Author: Lüthi, Martin P.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus 2013
• Subjects: Ela; Tive; The Cryosphere
• Online Access: https://hdl.handle.net/20.500.11850/75583; https://doi.org/10.3929/ethz-b-000075583

Mountain glaciers sample a combination of climate parameters – temperature, precipi-tation and radiation – by their rate of volume accumulation and loss. Flow dynamics actsas transfer function which maps volume changes to a length response of the glacier ter-minus. Long histories of terminus positions have been assembled for several glaciers in5the Alps. Here I analyze terminus position histories from an ensemble of seven glaciersin the Alps with a macroscopic model of glacier dynamics to derive a history of glacierequilibrium line altitude (ELA) for the time span 400–2010 C.E. The resulting climaticreconstruction depends only on records of glacier variations. The reconstructed ELAhistory is similar to recent reconstructions of Alpine summer temperature and Atlantic10Meridional Oscillation (AMO) index. Most reconstructed low-ELA periods coincide withlarge explosive volcano eruptions, hinting to mass balance reduction by volcanic radia-tive cooling. The glacier advances during the LIA, and the retreat after 1860 are thusexplained by temperature and volcanic cooling alone. ISSN:1994-0416 ISSN:1994-0424