GMBAL
Data
GMBAL is a dataset containing all available time series of annual and multi-annual mass balance measurements for the small glaciers of the world ( Cogley and Adams 1998; Cogley 2005; Kaser et al. 2006; Cogley 2009). ("Small" glaciers are all glaciers other than the two ice sheets.)

The measurement compilation is updated periodically and in R1501 runs up to the balance year 2013/14 for annual direct or glaciological measurements. Geodetic measurements, which are nearly all multi-annual, typically take longer to appear in the literature and as yet there are relatively few that extend into the 2010-2015 pentad.

The current release of GMBAL, available at left, is R1501. See below for earlier releases.

The map shows the distribution of mass-balance measurements (red and maroon pixels), which is very uneven. There are measurements in places with limited glacierization such as Mexico and New Guinea, but note the dense coverage of moderately glacierized but populous regions (Scandinavia, the Alps) in contrast with the sparse coverage of some of the heavily glacierized regions (Tibet, Alaska, Patagonia).

Distribution of glacier mass balance measurements


R1301 added a considerable number of measurements, and was used by, for example, Marzeion et al. 2014, who showed that the global fraction of glacier mass loss that is attributable to human activity is now clearly separable from, and larger than, natural mass loss; and by Marzeion et al. 2015 in a study that established that two independent reconstructions of glacier mass change since 1900 are mutually consistent.


R1203 was the first release to include significant amounts of information from regional geodetic measurements based on stereo photogrammetry, altimetry and interferometry (where "regional" means more extensive than the 1°×1° grid cells of GMBANAL's algorithm for spatial interpolation).


R1202 was used by Gardner et al. 2013, in which in-situ and remotely-sensed measurements and gravimetric measurements were reconciled to estimate global glacier mass change for 2003 to 2009. It was also the basis for much of the coverage of glacier mass balance in the Observations: Cryosphere chapter (see also the chapter on Sea Level Change) of the Fifth Assessment Report of Working Group I of the Intergovernmental Panel on Climate Change.


GMBAL now includes measurements from many more glaciers than those originally studied by Cogley and Adams (1998). It consists of seven files:
The data files are plain-text with fixed-width fields separated by commas. Please contact us if you have questions about GMBAL, and especially if you have corrections or additional mass-balance information, which are earnestly solicited.

A similar dataset has been published by Dyurgerov and Meier (1997a,b) and updated by Dyurgerov (2002), Dyurgerov and Meier (2005) and Dyurgerov (2010). Although it does not include geodetic measurements, the Dyurgerov-Meier dataset is broader in scope, including for example data on winter and summer balances where available. Still broader in scope is FoG, the Fluctuations of Glaciers database of the World Glacier Monitoring Service (Zemp et al. 2015). There is extensive overlap between the contents of all these databases. The strengths of GMBAL are that it includes rather more direct measurements of annual mass balance, and many more geodetic measurements of mass balance (mostly multi-annual), than the others.

References
Cogley, J.G., 2009, Geodetic and direct mass-balance measurements: comparison and joint analysis, Annals of Glaciology, 50(50), 96-100.

Cogley, J.G., 2005, Mass and energy balances of glaciers and ice sheets, in Anderson, M.G., ed., Encyclopaedia of Hydrological Sciences, 2555-2573 (volume 4). Wiley, New York.

Cogley, J.G., and W.P. Adams, 1998, Mass balance of glaciers other than the ice sheets, Journal of Glaciology, 44, 315-325.

Dyurgerov, M.B., 2010, Reanalysis of glacier changes: from the IGY to the IPY, 1960-2008, Materialy Glyatsiologicheskikh Issledovanij, 108, 5-116.

Dyurgerov, M.B., 2002, Glacier Mass Balance and Regime: Data of Measurements and Analysis, Occasional Paper 55, Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado. 268p., CD-ROM.

Dyurgerov, M.B., and M.F. Meier, 2005, Glaciers and the Changing Earth System: a 2004 Snapshot, Occasional Paper 58, Institute of Arctic and Alpine Research, University of Colorado, Boulder, Colorado. 117p.

Dyurgerov, M.B., and M.F. Meier, 1997a, Year-to-year fluctuations of global mass balance of small glaciers and their contribution to sea-level changes, Arctic and Alpine Research, 29, 392-401.

Dyurgerov, M.B., and M.F. Meier, 1997b, Mass balance of mountain and subpolar glaciers: a new global assessment for the period of instrumental records (1961-1990), Arctic and Alpine Research, 29, 379-391.

Gardner, A.S., G. Moholdt, J.G. Cogley, B. Wouters, A.A. Arendt, J. Wahr, E. Berthier, R. Hock, W.T. Pfeffer, G. Kaser, S.R.M. Ligtenberg, T. Bolch, M.J. Sharp, J.O. Hagen, M.R. van den Broeke and F. Paul, 2013, A reconciled estimate of glacier contributions to sea level rise: 2003 to 2009, Science, 340, 852-857.

Kaser, G., J.G. Cogley, M.B. Dyurgerov, M.F. Meier and A. Ohmura, 2006, Mass balance of glaciers and ice caps: consensus estimates for 1961-2004, Geophysical Research Letters, 33, L19501, doi: 10.1029/2006GL027511.

Marzeion, B., P.W. Leclercq, J.G. Cogley and A.H. Jarosch, 2015, Global glacier mass loss reconstructions during the 20th century are consistent, The Cryosphere, 9, 2399-2404.

Marzeion, B., J.G. Cogley, K. Richter and D. Parkes, 2014, Attribution of global glacier mass loss to anthropogenic and natural causes, Science, 345(6199), 919-921. doi: 10.1126/science.1254702. See also commentary by Marshall, S., 2014, Glacier retreat crosses a line, Science, 345(6199), 872.

Zemp, M., H. Frey, I. Gärtner-Roer, S.U. Nussbaumer, M. Hoelzle, F. Paul, W. Haeberli, F. Denzinger, A.P. Ahlstrøm, B. Anderson, S. Bajracharya, C. Baroni, L.N. Braun, B.E. Cáceres, G. Casassa, G. Cobos, L.R. Dávila, H. Delgado Granados, M.N. Demuth, L. Espizua, A. Fischer, K. Fujita, B. Gadek, A. Ghazanfar, J.O. Hagen, P. Holmlund, N. Karimi, Z.Q. Li, M. Pelto, P. Pitte, V.V. Popovnin, C.A. Portocarrero, R. Prinz, C.V. Sangewar, I. Severskiy, O. Sigurðsson, A. Soruco, R. Usubaliev and C. Vincent, 2015, Historically unprecedented global glacier decline in the early 21st century, Journal of Glaciology, 61(228), 745-762. doi: 10.3189/2015JoG15J017.