On the Persistent Spread in Snow-Albedo Feedback

TitleOn the Persistent Spread in Snow-Albedo Feedback
Publication TypeJournal Article
Year of Publication2013
JournalClimate Dynamics
Pages1-13
Date Published05/2013
Abstract / Summary

Snow-albedo feedback (SAF) is examined in 25 climate change simulations participating in the Coupled Model Intercomparison Project version 5 (CMIP5).  SAF behavior is compared to the feedback's behavior in the previous (CMIP3) generation of global models. SAF strength exhibits a fivefold spread across CMIP5 models, ranging from 0.03 to 0.16 W m-2 K-1 (ensemble-mean = 0.08 W m-2 K-1).  This accounts for much of the spread in 21st century warming of Northern Hemisphere land masses, and is very similar to the spread found in CMIP3 models. As with the CMIP3 models, there is a high degree of correspondence between the seasonal cycle and climate change feedback versions of the feedback, both in their magnitude and geographical footprint. The ensemble-mean SAF strength is close to an observed estimate of the real climate's seasonal cycle feedback strength. SAF strength is strongly correlated with the climatological surface albedo when the ground is covered by snow. The inter-model variation in this quantity is surprisingly large, ranging from 0.39 to 0.75.  Models with large surface albedo when these regions are snow-covered will also have a large surface albedo contrast between snow-covered and snow-free regions, and therefore a correspondingly large SAF. Widely-varying treatments of vegetation masking of snow-covered surfaces are probably responsible for the spread in surface albedo where snow occurs, and persistent spread in SAF in global climate models.

URLhttp://link.springer.com/article/10.1007%2Fs00382-013-1774-0
DOI10.1007/s00382-013-1774-0
Journal: Climate Dynamics
Year of Publication: 2013
Pages: 1-13
Date Published: 05/2013

Snow-albedo feedback (SAF) is examined in 25 climate change simulations participating in the Coupled Model Intercomparison Project version 5 (CMIP5).  SAF behavior is compared to the feedback's behavior in the previous (CMIP3) generation of global models. SAF strength exhibits a fivefold spread across CMIP5 models, ranging from 0.03 to 0.16 W m-2 K-1 (ensemble-mean = 0.08 W m-2 K-1).  This accounts for much of the spread in 21st century warming of Northern Hemisphere land masses, and is very similar to the spread found in CMIP3 models. As with the CMIP3 models, there is a high degree of correspondence between the seasonal cycle and climate change feedback versions of the feedback, both in their magnitude and geographical footprint. The ensemble-mean SAF strength is close to an observed estimate of the real climate's seasonal cycle feedback strength. SAF strength is strongly correlated with the climatological surface albedo when the ground is covered by snow. The inter-model variation in this quantity is surprisingly large, ranging from 0.39 to 0.75.  Models with large surface albedo when these regions are snow-covered will also have a large surface albedo contrast between snow-covered and snow-free regions, and therefore a correspondingly large SAF. Widely-varying treatments of vegetation masking of snow-covered surfaces are probably responsible for the spread in surface albedo where snow occurs, and persistent spread in SAF in global climate models.

DOI: 10.1007/s00382-013-1774-0
Citation:
Qu, X, and A Hall.  2013.  "On the Persistent Spread in Snow-Albedo Feedback."  Climate Dynamics 1-13.  https://doi.org/10.1007/s00382-013-1774-0.