Reconstructing glacier-based climates of LGM Europe and Russia – Part 2: A dataset of LGM climates derived from degree-day modelling of palaeo glaciers

Abstract

Abstract. The study of European and Russian Quaternary glacial-geological evidence during the last 15 years has generated sufficient to data to use former glacial extent as a proxy for Last Glacial Maximum (LGM) climate at a continental scale. Utilisation of such data is relevant for two reasons. First, continental to global scale proxy reconstructions of past climate are an important tool in the assessment of retrospective general circulation model (GCM) simulations. Second, the development of a multi-proxy approach will result in a more robust proxy based climate signal. A new and independent dataset of 36 LGM climate estimates derived from European and Russian mountain regions is presented in this paper. A simple glacier-climate model was used to establish the optimum LGM climate conditions for each region from a suite of over 4000 model climates using the principle of zero cumulative mass balance. Clear regional trends are present in the reconstructed LGM climates; temperature anomalies north of the Alps are 2°C and 5°C larger than those in the western and eastern Mediterranean, respectively. In Russia the model results suggest that both the Arctic Urals and Puterana Plateau were probably glaciated by small mountain glaciers during the LGM.

The deglaciation of the Sierra Nevada (Southern Spain)

“…Recent cosmogenic dates from marginal glaciated mountains of the eastern Pyrenees (Pallàs et al, 2006;Delmas et al, 2008) suggest a maximum extension of the glaciers nearer the global LGM and in closer agreement with the expansion suggested for most of Earth's glaciers, from 24 to 21 ka BP (Peltier and Fairbanks, 2006;Allen et al, 2007;Clark et al, 2009). This period is also suggested for other mountains in the NW of the Iberian Peninsula (Cowton et al, 2009) and has been confirmed for Sierra de Gredos and Guadarrama, in the center of the Peninsula (Palacios et al, , 2012Pedraza et al, 2011).…”

Past, present and future of mountain species of the French Massif Central – the case of Soldanella alpina L. subsp. alpina (Primulaceae) and a review of other plant and animal studies

“…For example, during the Last Glacial Maximum (LGM; c. 24,000–18,000 years ago), the MC region marked the southern limit of permafrost in western Europe (located at 45° N) and was covered by ice caps of up to 500 km 2 , similar to the situation in other mid‐elevation mountain ranges west and north of the Alps (e.g. in the Jura and the Vosges; Allen et al. , 2007; and further references therein).…”

“…For example, during the Last Glacial Maximum (LGM; c. 24,000-18,000 years ago), the MC region marked the southern limit of permafrost in western Europe (located at 45°N) and was covered by ice caps of up to 500 km 2 , similar to the situation in other mid-elevation mountain ranges west and north of the Alps (e.g. in the Jura and the Vosges; Allen et al, 2007; and further references therein). In consequence, during cold stages, in particular cold-tolerant/low-elevation species in the MC would be expected to have suffered from range contraction and population decline, resulting in loss of genetic diversity.…”

Reconstructing glacier-based climates of LGM Europe and Russia – Part 3: Comparison with GCM and pollen-based climate reconstructions

“…The mass balance of mountain glaciers is primarily controlled by winter accumulation and summer ablation (Porter 1977). The LGM climate reconstructions from glacial-geological evidence of Allen et al (2007b) were not able to involve changes in seasonality owing to the simplicity of the glacier-climate model used.…”

“…The aim of this paper is to develop our understanding of European LGM climate by presenting results from a suite of comparison analyses between the glacial-geological LGM climate reconstructions of Allen et al (2007b), the pollen climate reconstructions of Peyron et al (1998) and Tarasov et al (1999), and the HadCM3 simulation from PMIP2. The result is a quantitative assessment of the variability between palaeoclimate scenarios of LGM Europe, and an appreciation of the utility of glacial reconstructions in understanding past climates.…”