by rockdoc123 » Sun 22 Oct 2006, 16:50:37
The actual paper that this news article is based on is:
Monaghan, A.J., Bromwich, D.H., Fogt, R.L., Wang, S.-H., Mayeweski, P.A., Dixon,
D.A., Ekaykin, A., Frezzotti, M., Goodwin, I., Isaksson, E., Kaspari, S.D., Morgan, V.I., Oerter, H., Van Ommen, T.D., Van der Veen, C.J., and Wen, J. 2006. Insignificant change in Antarctic snowfall since the International Geophysical Year. Science, 313, 827-831
the paper is interesting but merely points to the uncertainties in climate models. The GCM’s currently in use predict increased snowfall in Antarctica due to a warming earth. If the observations by Monaghan et al are correct then the models are wrong and need to be revisited…so much for the science is over.
Further Monaghan note that they cannot refute that the East Antarctic Ice Sheet actually became thicker between 1992 and 2003 which was proven through radar measurements by Davis et al, 2005, simply that they cannot explain that thickening by increased snowfall. A quote from the Davis et al paper:
Davis, C.H., Li, Y. McConnell, J.R., Frey, M.M. and Hanna, E. 2005. Snowfall-driven
growth in East Antarctic Ice Sheet mitigates recent sea-level rise. Science, 308, 1898-1901
$this->bbcode_second_pass_quote('', 'S')atellite radar altimetry measurements indicate that the East Antarctic ice-sheet interior north of 81.6°S increased in mass by 45 ± 7 billion metric tons per year from 1992 to 2003. Comparisons with contemporaneous meteorological model snowfall estimates suggest that the gain in mass was associated with increased precipitation. A gain of this magnitude is enough to slow sea-level rise by 0.12 ± 0.02 millimeters per year
So if the thickening isn't due to increased snowfall what then? perhaps cooling rather than warming? Suggests more work needs to be done to me.
The increased mass balance of the Antarctic Ice sheet is also pointed to by a recent paper by Van de Berg et al, 2006 where they took all available mass balance observations and used them to recalibrate a climate model used to gather a best estimate of that mass balance. Their results suggest the ice sheet is growing at a greater rate than previously suggested and note that the only way they can refine this further is to acquire additional mass balance measurements from areas which are currently poorly sampled.
Van de Berg, W.J., van den Broeke, M.R., Reijmer, C.H., and van Meijgaard, E. 2006.
Reassessment of the Antarctic surface mass balance using calibrated output of a regional amtospheric climate model. Journal of Geophysical Research, 111, 10.1029/2005JD006495