Wednesday, February 20, 2013

New paper finds Antarctica has been gaining surface ice mass over past 150 years

A paper published today in The Cryosphere finds Antarctica has been gaining surface ice and snow accumulation over the past 150+ years, and finds acceleration in some areas noting, "a clear increase in accumulation of more than 10% has occurred in high Surface Mass Balance coastal regions and over the highest part of the East Antarctic ice divide since the 1960s." Furthermore, the paper notes, "Global climate models suggest that Antarctic snowfall should increase in a warming climate and mitigate rises in the sea level."

Top graph shows the entire Antarctic continent has been gaining surface ice mass over the past 150 years. According to the paper, Antarctic surface ice mass is presently growing by 2100 gigatons per year.
Even the allegedly "vulnerable" West Antarctic Ice Sheet [WAIS] surface mass balance has not changed in 150+ years.

The Cryosphere, 7, 303-319, 2013
www.the-cryosphere.net/7/303/2013/
doi:10.5194/tc-7-303-2013


A synthesis of the Antarctic surface mass balance during the last 800 yr

M. Frezzotti1, C. Scarchilli1, S. Becagli2, M. Proposito1, and S. Urbini3
1ENEA, Agenzia Nazionale per le nuove tecnologie, l'energia e lo sviluppo sostenibile, Rome, Italy
2Department of Chemistry, University of Florence, Sesto F.no, Italy
3INGV, Istituto Nazionale di Geofisica e Vulcanologia,, Rome, Italy

Abstract. Global climate models suggest that Antarctic snowfall should increase in a warming climate and mitigate rises in the sea level. Several processes affect surface mass balance (SMB), introducing large uncertainties in past, present and future ice sheet mass balance. To provide an extended perspective on the past SMB of Antarctica, we used 67 firn/ice core records to reconstruct the temporal variability in the SMB over the past 800 yr and, in greater detail, over the last 200 yr.

Our SMB reconstructions indicate that the SMB changes over most of Antarctica are statistically negligible and that the current SMB is not exceptionally high compared to the last 800 yr. High-accumulation periods have occurred in the past, specifically during the 1370s and 1610s. However, a clear increase in accumulation of more than 10% has occurred in high SMB coastal regions and over the highest part of the East Antarctic ice divide since the 1960s. To explain the differences in behaviour between the coastal/ice divide sites and the rest of Antarctica, we suggest that a higher frequency of blocking anticyclones increases the precipitation at coastal sites, leading to the advection of moist air in the highest areas, whereas blowing snow and/or erosion have significant negative impacts on the SMB at windy sites. Eight hundred years of stacked records of the SMB mimic the total solar irradiance during the 13th and 18th centuries. The link between those two variables is probably indirect and linked to a teleconnection in atmospheric circulation that forces complex feedback between the tropical Pacific and Antarctica via the generation and propagation of a large-scale atmospheric wave train.


 Final Revised Paper (PDF, 8075 KB)   Discussion Paper (TCD)   

3 comments:

  1. http://joannenova.com.au/2013/04/antarctica-gaining-ice-mass-and-is-not-extraordinary-compared-to-800-years-of-data/

    ReplyDelete
  2. http://link.springer.com/article/10.1007%2Fs00382-013-1903-9

    ReplyDelete
  3. http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00139.1?af=R

    ReplyDelete