The Arctic sea ice has retreated significantly over the past decades, and while Antarctic sea ice has been increasing slowly during the same period, the past year showed a record low Antarctic sea ice cover. The changes in ice cover affect the surface reflectivity (albedo) and are part of the ice-albedo feedback, by which temperature changes are re-inforced by changes in ice cover.

In this project the relation between sea ice extent in both hemispheres and albedo changes will be investigated. While the radiative heating due to the retreat of Arctic sea ice has been quantified, the corresponding analysis has not yet been performed for the Antarctic. Using satellite observations we can investigate the relation between sea ice extent and albedo, to determine how well sea ice variability determines albedo variations, and to what extent other parameters, like clouds and aerosols, are important. Satellite observations of top-of-the-atmosphere radiative fluxes are available from year 2000 and will soon be updated to cover the winter of 2016, allowing for inclusion of the record-low Antarctic sea ice extent in the analysis. In these data we will look for local and regional albedo signals and relate them to estimated changes in sea ice concentration, compare the hemispheres and quantify the radiative heating the sea ice changes are causing. Time allowing, a similar analysis can also be performed using output from one or several global climate models, for comparison.

The project focuses on data analysis, and Matlab/Python or similar software will be used to process and plot data. 

Some references:

Pistone, K., Eisenmann, I. and Ramanathan, V. (2014) Observational determination of albedo decrease caused by vanishing Arctic sea ice, Proc. Nat. Acad. Sci. USA, 111 (9), 3322-3326

http://www.pnas.org/content/111/9/3322.full

Flanner, M. G., Shell, K. M., Barlage, M., Petrovich, D. K. and Tschudi, M. A. (2011) Radiative forcing and albedo feedback from the Northern Hemisphere cryosphere between 1979 and 2008, Nature Geosci., 4, 151-155

http://www.nature.com/ngeo/journal/v4/n3/abs/ngeo1062.html

Petrovich, D. K., Light, B., Eicken, H., Jones, K., Runciman, K. and Ngheim, S. V. (2007) Increasing solar heating of the Arctic Ocean and adjacent seas, 1979-2005: Attribution and role in the ice-albedo feedback, Geophys. Res. Lett., 34 L19505

http://sites.fas.harvard.edu/~scia30/2008/SOURCEBOOK/2007_Perovich_GRL.pdf