• Main Authors: M. R. Van Den Broeke, B. Legrésy, Quantifying The
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Antarctic; Austral; The Antarctic; Antarc*; Ice Sheet
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.635.1890; http://hal-ups-tlse.archives-ouvertes.fr/docs/00/98/22/95/PDF/2012_Ligtenberg_GRL.pdf

[1] One way to estimate the mass balance of an ice sheet is to convert satellite observed surface elevation changes into mass changes. In order to do so, elevation and mass changes due to firn processes must be taken into account. Here, we use a firn densification model to simulate seasonal variations in depth and mass of the Antarctic firn layer, and assess their influence on surface elevation. Forced by the seasonal cycle in temperature and accumulation, a clear seasonal cycle in average firn depth of the Antarctic ice sheet (AIS) is found with an amplitude of 0.026 m, representing a volume oscil-lation of 340 km3. The phase of this oscillation is rather con-stant across the AIS: the ice sheet volume increases in austral autumn, winter and spring and quickly decreases in austral summer. Seasonal accumulation differences are the major driver of this annual ‘breathing’, with temperature fluctuations playing a secondary role. The modeled seasonal elevation sig-nal explains!31 % of the seasonal elevation signal derived from ENVISAT radar altimetry, with both signals having