Policy Documents

Overview and Assessment of Antarctic Ice-Sheet Mass Balance Estimates: 1992–2009

H. Jay Zwally, Mario B. Giovinetto –
March 31, 2011

Zwally and Giovinetto compare the mass balance estimates of the Antarctic Ice Sheet (AIS) predicted in the 2007 report of the Intergovernmental Panel on Climate Change, as well as estimates in more recent reports, to real world numbers. In an attempt to determine which set of observations is the most correct, the authors "compare the various estimates, discuss the methodology used, and critically assess the results," and "modify the IOM estimate using (1) an alternate extrapolation to estimate the discharge from the non-observed 15% of the periphery, and (2) substitution of input from a field data compilation for input from an atmospheric model in 6% of the area." Zwally and Giovinetto state "although recent reports of large and increasing rates of mass loss with time from GRACE-based studies cite agreement with IOM results," they say the evidence "does not support that conclusion."