Ice Sheet Surface and Subsurface Melt Water Discrimination Using Multi‐Frequency Microwave Radiometry

Abstract

Slater et al., 2021). Monitoring and understanding its evolution is required to estimate the amount of meltwater that escapes to surrounding oceans rather than remains as refrozen water in land ice. The ice sheets experience significant seasonal surface melt events that start a complex chain of liquid water infiltration, retention, and refreeze processes (e.g., Nghiem et al., 2012;Picard et al., 2007). For the ice sheet mass balance estimation, understanding these processes is critical (Janssens and Huybrechts, 2000) and mass balance model studies would particularly benefit from improved initialization of liquid water at the surface (van As et al., 2016). Many mass balance models depend on inferred liquid water distribution in the snow and firn based on albedo and snow/ firn structural parameters (such as density and pore space, which affect hydraulic and thermal conductivity) in absence of measured values (e.g., Langen et al., 2017). Microwave radiometry in the right frequency range is an effective tool for detecting melt because of its sensitivity to the change of the permittivity of the ice sheet during melt events (e.g.

Quantifying Antarctic‐Wide Ice‐Shelf Surface Melt Volume Using Microwave and Firn Model Data: 1980 to 2021

“…Microwave radiometers (19 GHz) record brightness temperatures that depend primarily on the snow temperature and emissivity (Colliander et al., 2022; Zwally, 1977). When liquid water exists in the snow, absorption significantly increases, resulting in increased microwave emissivity, and thus substantially higher brightness temperatures (Liu et al., 2006; Zwally & Fiegles, 1994).…”

Remote Sensing of Surface Melt on Antarctica: Opportunities and Challenges

“…Moreover, the different frequencies of active and microwave sensors provide the opportunity to derive the depth of the meltwater. A recent study attempted 890 to discriminate between surface and near-surface melt over the Greenland Ice Sheet using multiple frequencies of passive microwave sensors [49]. When combining optical, active, and passive microwave signals, an even more detailed profile of meltwater depths might be acquired.…”

Influence of Supraglacial Lakes on Accuracy of Inversion of Greenland Ice Sheet Surface Melt Data in Different Passive Microwave Bands

“…Mousavi et al harnessed NASA's Soil Moisture Active Passive (SMAP) satellite L-band data to calculate the melting intensity of the GrIS from 2015 to 2021 [13]. Colliander et al employed SMAP L-band and AMSR2 (Advanced Microwave Scanning Radiometer-2) K-and Ka-band data together to calculate the LWC of the GrIS [14].…”