Multidecadal to Centennial Climate Variability: Assessing the Conditions for the Glaciation of Tropical Mountains

Duration: 
2010 - 2015
Participants: 
Ben Marzeion (PI)
Thomas Mölg
Georg Kaser
Alexander H. Jarosch
Martin Großhauser
Abstract: 

Glaciers throughout the world, including tropical glaciers, have been shrinking over most of the 20th century. Generally, this is attributed to global warming. While climate-glacier interactions in the mid and high latitudes are reasonably well studied, glaciers in the tropics are typically harder to access, situated in a region characterized through extremely sparse observations, and therefore less well understood.

Recent glaciological studies have lead to the conclusion that tropical glaciers are often more sensitive to variability in moisture than temperature, and connections have been drawn between glacier mass balance and large-scale climate modes, e.g. variability of the Indian Ocean Dipole Mode influencing mass balance on Kilimanjaro, Tanzania, and low-frequency modulation of El Nino/Southern Oscillation influencing the glaciers of the Cordillera Blanca, Peru. However, the respective roles of anthropogenic (e. g. emission of greenhouse gases) or natural (e. g. volcanism) changes to the forcing of the climate system, internal variability, or interactions of these two, remain unclear.

In order to understand the currently observed strong retreat of tropical glaciers around the world, and to assess their prospect over the next century, it is important to understand the climate dynamics governing atmospheric conditions at the site of these glaciers, i.e., in the tropical mid troposphere.

The project will combine the best available glaciological observation from three continents, reconstructions of past glacier extent, and multi-century ensemble climate reconstructions from four different state-of-the-art, global coupled climate models in order to gain insight into the large scale climate dynamics governing the conditions at the glacier sites and acting on glacier timescales.

The modes of multidecadal to centennial climate variability will be identified, and the past atmospheric variability and its effect on the glaciated sites will be reconstructed. These reconstructions will be validated using direct observations, and proxy-reconstructions of atmospheric state and the glacier extent. The relative importance of internal variability and anthropogenic influence during the 20th century will be assessed. This will lead to conclusions about long-term predictability, and – if deemed possible – to estimates of the most likely atmospheric conditions that the glaciers will experience during the 21st century.

Funding Agency: 
Austrian Science Fund (FWF)
Funding Amount: 
€300 000

Related Publications

Gurgiser, W.; Marzeion, B.; Nicholson, L.; Ortner, M.; Kaser, G. , 2013 , Modeling energy and mass balance of Shallap Glacier, Peru , The Cryosphere , 7 , 1787 - 1802 , DOI: 10.5194/tc-7-1787-2013
gurgiser_etal_13.pdf , BibTex , EndNote Tagged

Hofer, M.; Marzeion, B.; Mölg, T. , 2012 , Comparing the skill of different reanalyses and their ensembles as predictors for daily air temperature on a glaciated mountain (Peru) , Clim Dyn , 39 , 1969 - 1980 , DOI: 10.1007/s00382-012-1501-2
hofer_etal_12.pdf , BibTex , EndNote Tagged

Mölg, T.; Großhauser, M.; Hemp, A.; Hofer, M.; Marzeion, B. , 2012 , Limited forcing of glacier loss through land-cover change on Kilimanjaro , Nature Climate change , 2 , 254 - 258 , DOI: 10.1038/nclimate1390
moelg_etal_12.pdf , BibTex , EndNote Tagged

Hofer, M.; Mölg, T.; Marzeion, B.; Kaser, G. , 2010 , Empirical-statistical downscaling of reanalysis data to high-resolution air temperature and specific humidity above a glacier surface (Cordillera Blanca, Peru) , J. Geophys. Res. , 115 , D12120 , DOI: 10.1029/2009JD012556
hofer_etal_10.pdf , BibTex , EndNote Tagged

Kaser, G.; Großhauser, M.; Marzeion, B. , 2010 , Contribution potential of glaciers to water availability in different climate regimes , Proceedings of the National Academy of Sciences , 107 , 20223 - 20227 , DOI: 10.1073/pnas.1008162107
kaser_etal_10.pdf , BibTex , EndNote Tagged

Marzeion, B.; Timmermann, A.; Murtugudde, R.; Jin, F.F. , 2005 , Biophysical Feedbacks in the Tropical Pacific , J. Climate , 18 , 58 - 70 , DOI: 10.1175/JCLI3261.1
marzeion_etal_05.pdf , BibTex , EndNote Tagged