C034-05
Surface Melting Drives Fluctuations in Airborne Radar Penetration in West Central Greenland

Thursday, 10 December 2020: 17:46
Virtual
Inès Otosaka1, Andrew Shepherd2, Tania G D Casal3, Alex Coccia Sr4, Malcolm W Davidson3, Alessandro Di Bella5, Xavier Fettweis6, Rene Forsberg7, Veit Helm8, Anna Hogg9, Sine Munk Hvidegaard5,10, Adriano Lemos2, Karlus Macedo11, Peter Kuipers Munneke12, Tommaso Parrinello13, Sebastian B Simonsen14, Henriette Skourup10 and Louise Sandberg Sorensen15, (1)University of Leeds, Leeds, LS2, United Kingdom, (2)University of Leeds, Leeds, United Kingdom, (3)ESA/ESTEC, Noordwijk, Netherlands, (4)MetaSensing, Noordwijk, Netherlands, (5)Technical University of Denmark, Kgs. Lyngby, Denmark, (6)University of Liège, Liège, Belgium, (7)Technical University of Denmark - Space, Kongens Lyngby, Denmark, (8)Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research Bremerhaven, Bremerhaven, Germany, (9)CPOM, University of Leeds, Leeds, United Kingdom, (10)National Space Institute, Copenhagen, Denmark, (11)Meta sensing, Noordwijk, Netherlands, (12)Utrecht University, Institute for Marine and Atmospheric Research Utrecht, Utrecht, Netherlands, (13)ESA - European Space Agency, Frascati, Italy, (14)DTU Space, Kgs. Lyngby, Denmark, (15)National Space Institute, Copenhagen Oe, Denmark
Recorded Presentation
Abstract:
Greenland Ice Sheet surface melting has increased since the 1990s, affecting the rheology and scattering properties of the near-surface firn. We combine firn cores and modelled firn densities with seven years of CryoVEx airborne Ku-band (13.5 GHz) radar profiles to quantify the impact of melting on microwave radar penetration in West-Central Greenland. Although annual layers are present in the Ku-band radar profiles to depths up to 15 m below the ice sheet surface, fluctuations in summer melting strongly affect the degree of radar penetration. The extreme melting in 2012, for example, caused an abrupt 6.2 ± 2.4 m decrease in Ku-band radar penetration. Nevertheless, retracking the radar echoes mitigates this effect, producing surface heights that agree to within 13.9 cm of coincident airborne laser measurements. We also examine two years of Ka-band (34.5 GHz) airborne radar data and show that the degree of penetration is half that of coincident Ku-band.
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