Mass of ice lost (or gained) from Greenland expressed as time series
For this sub-challenge enough data was available to complete it. The data on this topic is widely spread and freely available. No clashes were found in the data found, the datasets combined from different sources gave the same results. For this sub-challenge we feel no major gaps are present, however the data is quite spread-out both spatially and temporally.
Figure 1: ice loss in Greenland in cm/year. Source: NASA.
Figure 2: Cumulative change in the total mass (in Gigatonnes, Gt) of the Greenland Ice Sheet between April 2002 and April 2015 estimated from GRACE measurements. Each symbol is an individual month and the orange asterisks denote April values for reference. (source: Tedesco et al. 2015)
Figure 3: dM/dt is total rate of mass change, dMa/dt is the component driven by temporal variations in snow accumulation, and dMbd/dt is the component driven by ablation and ice dynamics, all averaged by 500m elevation bands over the ice sheet for the 1992–2002 and 2003–07 periods. Circled symbols are totals for all elevations weighted by area. (source: Zwally et al. 2011)
Figure 4: Components of mass change by drainage system. dMa/dt, dMbd/dt, dM/dt (Gt a–1) averaged over 500m elevation bands for the eight drainage systems for 1992–2002 (black) and 2003–07 (red) with totals for 1992–2002 (black symbols) and 2003–07 (red symbols). Accumulation-driven mass increases are largest in DS3, DS4, DS7 and DS8, and dynamic-/ablation-driven thinning is largest in DS3, DS4 and DS8 and very small in DS1, DS2, DS5 and DS6. (source: Zwally et al. 2011)
For this sub-challenge, the following sources were used:
- Tedesco, M., J. E. Box, J. Cappelen, R. S. Fausto, X. Fettweis, K. Hansen, T. Mote, C. J. P. P. Smeets, D. van As, R. S. W. van de Wal & J. Wahr, 2015. Greenland Ice Sheet. In: Arctic Report Card: Update for 2015.
- Zwally, H.J., J. Li, A. C. Brenner, M. Beckley, H. G. Cornejo, J. Dimarzio, M. B. Giovinetto, T. A. Neumann, J. Robbins, J. L. Saba, D. Yi & W. Wang, 2011. Greenland ice sheet mass balance: distribution of increased mass loss with climate warming; 2003-07 versus 1992-2002. Journal of Glaciology 201(57): 88-102. http://icesat4.gsfc.nasa.gov/cryo_data/publications/ZwallyETALJGlac2011Jan.pdf
- Hanna, E. P. Huybrechts, J. Cappelen, K. Steffen, R. C. Bales, E. Burgess, J. R.McConnell, J. Peder Steffensen, M. Van den Broeke, L. Wake, G. Bigg, M. Griffiths & Deniz Savas, 2011. Greenland ice sheet surface mass balance between 1870 to 2010 based on twentieth century reanalysis and links with global climate forcing. Journal of Geophysical research 116: 20p. http://www.staff.science.uu.nl/~broek112/home.php_files/Publications_MvdB/2011_Hanna_JGR.pdf
- NASA: http://icesat4.gsfc.nasa.gov/