Comparing Greenland Ice Sheet Melt Variability From Different Satellite Passive Microwave Remote Sensing Products Over a Common 5-year Record

Satellite microwave brightness temperature (Tb) observations over the Greenland Ice Sheet permit determination of melted/frozen snow conditions at spatial and temporal scales that are uniquely suited for climate model validation metrics ice sheet change. Strong sensitivity to presence liquid water in snowpack is clear. Yet, a host unique microwave-derived melt products covering available, each based on different methodology, with unknown inter-product agreement. Here, we compared five published common 5-year (2003–2007) record establish compatibility between agreement situ from network on-ice weather stations (AWS) spanning sheet. A sixth product, leveraging both Tb seasonal trends diurnal variability, was also introduced included comparison. We found variable observations, estimates emissions modeling newly presented Adaptive Threshold (ADT) algorithm showing best performance AWS sites more than 1-day average annual period (e.g., 68.9% ADT days consistent observations; 31.1% frozen contrasting observed melt). Spatial patterns melting varied products. The showed substantial spread occurrence even Product differences were generally larger under higher conditions; whereby, fraction experiencing ≥25 year ranged 4 25% While long-term satellite records have consistently shown increasing decadal extent, our results imply frequency any given location, particularly interior where less prevalent, still subject significant uncertainty.