Reconstructing glacier-based climates of LGM Europe and Russia – Part 3: Comparison with GCM and pollen-based climate reconstructions
1School of Geographical Sciences, University of Bristol, University Road, Bristol, BS8 1SS, UK
2School of GeoSciences, University of Edinburgh, Grant Institute, King's Buildings, West Mains Road, Edinburgh, EH9 3JW, UK
*now at: Landmark Information Group, 5-7 Abbey Court, Eagle Way, Sowton, Exeter, EX2 7HY, UK
Abstract. Understanding past climates using GCM models is critical to confidently predicting future climate change. Although previous analysis of GCM simulations have shown them to under predicted European glacial temperature anomalies (the difference between modern and glacial temperatures) such analyses have focused primarily on results from glacial simulations alone. Here we compare glacial maximum GCM results with the palaeoenvironment derived from glacier-climate modelling. The comparison confirms that GCM anomalies are under predicted, and that this is due to modern conditions that are modelled too cold and glacial temperatures that are too warm. The result is that CGM results, if applied to a glacier mass balance model, over predict the extent of glaciers today, and under predict their extent at the last glacial (as depicted in glacial geological reconstructions). Effects such as seasonality and model parameterisation change the magnitude of the under prediction but still fail to match expected glacial conditions.