[LINK] Surface Temperatures Lowering in Antarctica

TKoltai tomk at unwired.com.au
Sat Feb 25 20:40:10 AEDT 2012



Quote/ [From: http://www.agu.org/pubs/crossref/pip/2011JC007126.shtml]
Thirty years of elevation change on Antarctic Peninsula ice shelves from
multi-mission satellite radar altimetry - Fricker & Padman (2012)

Abstract: "We use data acquired between 1978 and 2008 by four satellite
radar altimeter missions (Seasat, ERS-1, ERS-2 and Envisat) to determine
multi-decadal elevation change rates (dhi/dt) for six major Antarctic
Peninsula (AP) ice shelves. In areas covered by the Seasat orbit (to
72.16oS), regionally-averaged 30-year trends were negative (surface
lowering), with rates between -0.03 and -0.16 m a-1. Surface lowering
preceded the start of near-continuous radar altimeter operations that
began with ERS-1 in 1992. The average rate of lowering for the first 14
years of the period was typically smaller than the 30-year average; the
exception was the southern Wilkins Ice Shelf, which experienced
negligible lowering between 2000 and 2008, when a series of large
calving events began. Analyses of the continuous ERS/Envisat time series
(to 81.5o) for 1992-2008 reveal a period of strong negative dhi/dt on
most ice shelves between 1992 and 1995. Based on prior studies of
regional atmospheric and oceanic conditions, we hypothesize that the
observed elevation changes on Larsen C Ice Shelf are driven primarily by
firn compaction while the western AP ice shelves are responding to
changes in both surface mass balance and basal melt rates. Our time
series also show that large changes in dhi/dt can occur on interannual
time scales, reinforcing the importance of long time series altimetry to
separate long-term trends associated with climate change from
interannual to interdecadal natural variability."

Citation: Fricker, H. A. and L. Padman (2011), Thirty years of elevation
change on Antarctic Peninsula ice shelves from multi-mission satellite
radar altimetry, J. Geophys. Res., doi:10.1029/2011JC007126, in press.

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