Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers ...

• Main Authors: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, Marco, Hall, D. K., Steffen, K.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Columbia University 2012
• Subjects: Albedo; Meltwater; Climatic geomorphology; Geomorphology; Runoff; Ice sheets; Geology; FOS: Earth and related environmental sciences; Climatic changes; Greenland; glacier; Ice Sheet
• Online Access: https://dx.doi.org/10.7916/d8qn66pt; https://academiccommons.columbia.edu/doi/10.7916/D8QN66PT

Greenland ice sheet mass loss has accelerated in the past decade responding to combined glacier discharge and surface melt water runoff increases. During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. ...