In a recent paper we used thermodynamic calculations to suggest that differences in simulated Arctic downwelling longwave radiation have major implications for underlying sea ice in sixteen global climate models (GCMs) being evaluated for the IPCC Fourth Assessment Report (AR4), and we discussed the possibility that albedo tuning may help explain the extent to which simulated present-day sea ice in these models agrees with observations despite the atmospheric model errors [Eisenman et al., 2007]. DeWeaver et al. [2008] compare our albedo sensitivity calculations with simulations carried out using a version of CCSM3, which is one of the sixteen GCMs considered in our study. They find that CCSM3 is significantly less sensitive to sea ice albedo than our thermodynamic calculations demonstrated, and hence they conclude that ice albedo may not be as effective a GCM ``tuning knob'' as we suggested. We thank them for their comment and for the opportunity to discuss further the issue of sea ice sensitivity in GCMs.

Last Updated: 2008-08-25