Modelled glacier equilibrium line altitudes during the mid-Holocene in the southern mid-latitudes

Bravo, C.; Rojas, M.; Anderson, B. M.; Mackintosh, A. N.; Sagredo, E.; Moreno, P. I.
March 2015
Climate of the Past Discussions;2015, Vol. 11 Issue 2, p603
Academic Journal
Glacier behaviour during the mid-Holocene (MH, 6000 year BP) in the Southern Hemisphere provides observational data to constrain our understanding of the origin and propagation of palaeo-climatic signals. We examine the climatic forcing of glacier expansion in the MH by evaluating modelled glacier equilibrium line altitude (ELA) and climate conditions during the MH compared with pre-industrial time (PI, year 1750) in the mid latitudes of the Southern Hemisphere, specifically in Patagonia and the South Island of New Zealand. Climate conditions for the MH are obtained from PMIP2 models simulations, which in turn force a simple glacier mass balance model to simulate changes in equilibrium-line altitude during this period. Climate conditions during the MH show significantly (p ≤ 0.05) colder temperatures in summer, autumn and winter, and significantly (p ≤ 0.05) warmer temperatures in spring. These changes are a consequence of insolation differences between the two periods. Precipitation does not show significant changes, but exhibits a temporal pattern with less precipitation from August to September and more precipitation from October to April during the MH. In response to these climatic changes, glaciers in both analysed regions have an ELA that is 15-33m lower than PI during the MH. The main causes of this difference are the colder temperature during the MH, reinforcing previous results that mid-latitude glaciers are more sensitive to temperature change compared to precipitation changes. Differences in temperature have a dual effect on mass balance. First, during summer and early autumn less energy is available for melting. Second in late autumn and winter, lower temperatures cause more precipitation to fall as snow rather than rain, resulting in more accumulation and higher surface albedo. For these reasons, we postulate that the modelled ELA changes, although small, may help to explain larger glacier extents observed in the mid Holocene in both South America and New Zealand.


Related Articles

  • Climate and African precipitation changes in the mid-Holocene simulated using an Earth System Model MIROC-ESM. Ohgaito, R.; Sueyoshi, T.; Abe-Ouchi, A.; Hajima, T.; Watanabe, S.; Kim, H.-J.; Yamamoto, A.; Kawamiya, M. // Climate of the Past Discussions;2012, Vol. 8 Issue 4, p3277 

    The importance of evaluating models using paleoclimate simulations is becoming more recognized in efforts to improve climate projection. To evaluate an integrated Earth System Model, MIROC-ESM, we performed simulations in time-slice experiments for the mid-Holocene (6000 yr before present, 6 ka)...

  • Using paleo-climate comparisons to constrain future projections in CMIP5. Schmidt, G. A.; Annan, J. D.; Bartlein, P. J.; Cook, B. I.; Guilyardi, E.; Hargreaves, J. C.; Harrison, S. P.; Kageyama, M.; LeGrande, A. N.; Konecky, B.; Lovejoy, S.; Mann, M. E.; Masson-Delmotte, V.; Risi, C.; Thompson, D.; Timmermann, A.; Tremblay, L.-B.; Yiou, P. // Climate of the Past Discussions;2013, Vol. 9 Issue 1, p775 

    We present a description of the theoretical framework and "best practice" for using the paleo-climate model component of the Coupled Model Intercomparison Project (Phase 5) (CMIP5) to constrain future projections of climate using the same models. The constraints arise from measures of skill in...

  • Dendroglaciological investigations of mid- to late-Holocene glacial activity in the Mt. Waddington area, British Columbia Coast Mountains, Canada. Coulthard, Bethany; Smith, Dan J; Lacourse, Terri // Holocene;Jan2013, Vol. 23 Issue 1, p93 

    Dendroglaciological investigations near Mt. Waddington in the central British Columbia Coast Mountains provide an enhanced perspective of Holocene glacial activity. Field investigations at Confederation, Franklin, and Jambeau glaciers led to the discovery of subfossil wood mats encased in...

  • Contrasting patterns of climatic changes during the Holocene in the Central Mediterranean (Italy) reconstructed from pollen data. Peyron, O.; Magny, M.; Goring, S.; Joannin, S.; de Beaulieu, J.-L.; Brugiapaglia, E.; Sadori, L.; Garfi, G.; Kouli, K.; Ioakim, C.; Combourieu-Nebout, N. // Climate of the Past Discussions;2012, Vol. 8 Issue 6, p5817 

    Lake-level records from Italy suggest a north--south climatic partition in the Central Mediterranean during the Holocene with respect to precipitation, but the scarcity of reliable palaeoclimatic records in the North and Central-Southern Mediterranean means new evidence is needed to validate...

  • A model comparison study for the Antarctic region: present and past. Maris, M. N. A.; de Boer, B.; Oerlemans, J. // Climate of the Past Discussions;2011, Vol. 7 Issue 5, p3583 

    Eighteen global climate models (GCMs) are compared to reference data for the present, the mid-Holocene (MH) and the last glacial maximum (LGM) for the Antarctic region. For the present, the reference data come from a regional climate model. GCM results for the past are compared to ice core data....

  • Deglacial and Holocene vegetation and climatic changes in the southern Central Mediterranean from a direct land-sea correlation. Desprat, S.; Combourieu-Nebout, N.; Essallami, L.; Sicre, M. A.; Dormoy, I.; Peyron, O.; Siani, G.; Roumazeilles, V. Bout; Turon, J. L. // Climate of the Past;2013, Vol. 9 Issue 2, p767 

    Despite a large number of studies, the long-term and millennial to centennial-scale climatic variability in the Mediterranean region during the last deglaciation and the Holocene is still debated, including in the southern Central Mediterranean. In this paper, we present a new marine pollen...

  • Reconstructing past precipitation from lake levels and inverse modelling for Andean Lake La Cocha. Boxel, J.; González-Carranza, Z.; Hooghiemstra, H.; Bierkens, M.; Vélez, M. // Journal of Paleolimnology;Jan2014, Vol. 51 Issue 1, p63 

    Knowledge of paleoclimates and past climate change is important to put recent and future climate change in perspective. In the absence of well-developed methodology to reconstruct paleoprecipitation the majority of climate reconstructions focus on temperature, whereas precipitation is an equally...

  • Recent Antarctic Peninsula warming relative to Holocene climate and ice-shelf history. Mulvaney, Robert; Abram, Nerilie J.; Hindmarsh, Richard C. A.; Arrowsmith, Carol; Fleet, Louise; Triest, Jack; Sime, Louise C.; Alemany, Olivier; Foord, Susan // Nature;9/6/2012, Vol. 489 Issue 7414, p141 

    Rapid warming over the past 50?years on the Antarctic Peninsula is associated with the collapse of a number of ice shelves and accelerating glacier mass loss. In contrast, warming has been comparatively modest over West Antarctica and significant changes have not been observed over most of East...

  • Precipitation as the main driver of Neoglacial fluctuations of Gualas glacier, Northern Patagonian Icefield. Bertrand, S.; Hughen, K. A.; Lamy, F.; Stuut, J.-B. W.; Torrejón, F.; Lange, C. B. // Climate of the Past Discussions;2011, Vol. 7 Issue 5, p2937 

    Glaciers are frequently used as indicators of climate change. However, the link between past glacier fluctuations and climate variability is still highly debated. Here, we investigate the mid- to late-Holocene fluctuations of Gualas Glacier, one of the northernmost outlet glaciers of the...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics