We assumed that the post-fire trajectory of albedo-driven radiative forcing
followed MODIS albedo (Fig. 2A, dashed line, right axis). Albedo-driven radiative
forcing increased from -5.0 W m-2 in year 1 to -8.5 W m-2 in year 10. During a deciduous
phase (years 10-30), radiative forcing remained constant at -8.5 W m-2 reflecting
sustained levels of elevated albedo during both spring and summer (Fig. 2). After year
30, radiative forcing decreased linearly, and was assumed to equal zero at year 55 and for
all subsequent years. Averaged over years 0-80, albedo-driven radiative forcing was -4.2
± 2.0 W m-2. For this longer interval, our error estimate includes the components
described above for years 3-5 (uncertainty from interannual variability in snow cover and
use of the CRM) as well as an additional 20% reflecting uncertainty associated with
estimating the post-fire trajectory of albedo from MODIS.