To estimate Fa from the changes in surface albedo within the Donnelly Flats burn
perimeter, we first obtained Fi,tropo from CRM, driving the model with observations of
surface albedo and incoming shortwave radiation at our field sites (the approach is
described in section 1.5). As with the snow and sea ice forcing approach described above,
in a second step we assumed that the ratio Fi,tropo was the same as Fa based on northern
surface albedo simulations obtained from a global climate model (Table 11 from H97).