Discussion of Increased ice losses from Antarctica detected by CryoSat-2 - short periods of 3 years of data should not be used to infer any trend

Author(s): A.Parker

The latest paper[1] uses a computational record less than 36 months long based on the Cryosat-2 satellite data to claimthat “Between 2010 and 2013, West Antarctica, East Antarctica, and the Antarctic Peninsula changed in mass by -134 ± 27, -3 ± 36, and -23 ± 18 Gtyr-1 respectively”to conclude that”We estimate that, since 2010, the average Antarctic ice sheet contribution to global sea level rise has been 0.45 ± 0.14 mm yr-1" It is commented here that the novel computation of the ice volume from the satellite altimetry data and other supporting indirect measurements used for validation and calibration is a difficult task still under development. The ice volume result has to be considered in the correct perspective togetherwith the other information available for the region, fromlocal temperature measurements by thermometers, to satellite inferred measurements of surface temperatures and sea ice extent, certainlymuchmore reliable and covering amuchmore significant period. It is shown here that the temperatures and the sea ice extent are subject to intense inter-annual and multi-decadal oscillations about a cooling and expanding trend, and the 3 years’ time window is misleading magnifying the effect of these oscillations about a longer term trend. Finally, the computed volume of ice melted appears excessive being the claimed global sea level rise not supported by tide gauge, satellite altimetry and salinity measurements.

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