Greenland ice sheet elevation changes from satellite altrimetry

Speaker: 
Kirill Khvorostosky
Affiliation: 
NERSC
Seminar Date: 
22. November 2012 - 12:30 - 13:00
Location: 
Lecture room, Ground Floor, NERSC

A change in surface elevation is an important characteristic of the ice sheet behavior, which is used in mass balance studies. Analysis of the Greenland ice sheet (GrIS) elevation time series (1992-2010) derived from ERS-1, ERS-2 and Envisat satellite radar altimeter measurements will be presented. Problems of the ice-sheet elevation change estimation from satellite radar altimetry will be discussed. We will present the improved methods for merging altimeter measurements from different satellites and for applying backscatter correction accounting for penetration of radar altimeter signal into snow surface. Created time series show remarkable inter-annual variability in the interior of the GrIS with the overall elevation increase from 1992 to 2006 followed by the elevation decrease mostly caused by the changes over western flank of the ice sheet. Over marginal low‚Äźelevation areas significant elevation decrease started from 2000 is revealed. Comparison of elevation time series derived using temporally consistent altimeter measurements from Envisat and ICESat satellites provided assessment of the observed elevation changes uncertainty.