2011: Radiative forcing and albedo feedback from the Northern Hemisphere cryosphere between 1979 and 2008

• Main Authors: M. G. Flanner, K. M. Shell, M. Barlage, D. K. Perovich, M. A. Tschudi
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Sea ice
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.397.4906; http://www.see.ed.ac.uk/~shs/Climate change/Climate model results/Flanner ICE feedbacks.pdf

The extent of snow cover 1 and sea ice 2 in the Northern Hemisphere has declined since 1979, coincident with hemispheric warming and indicative of a positive feedback of surface reflectivity on climate. This albedo feedback of snow on land has been quantified from observations at seasonal timescales 3–6, and century-scale feedback has been assessed using climate models 7–10. However, the total impact of the cryosphere on radiative forcing and albedo feedback has yet to be determined from measurements. Here we assess the influence of the Northern Hemisphere cryosphere on Earth’s radiation budget at the top of the atmosphere—termed cryosphere radiative forcing—by synthesizing a variety of remote sensing and field measurements. We estimate mean Northern Hemisphere forcing at −4.6 to −2.2 W m −2, with a peak in May of −9.0 ± 2.7 W m −2. We find that cyrospheric cooling