With CRM, we made four sets of model runs: with and without cloud cover and
with control and burn surface albedo. For all simulations we used monthly mean profiles
of atmospheric temperature, specific humidity, and ozone from the European Centre for
Medium-Range Weather Forecasts 40 years Reanalysis product (27) and we assumed an
aerosol optical depth of 0.14. For the cloud cover simulations, we imposed a single 100%
cloud cover layer in the model at the 974 mb level, with a liquid water content of 100 g
m
-2. For each set of model runs, we made a simulation for each hour of each month (a
total of 288 simulations) to capture both diurnal and seasonal variations in solar
geometry. We assumed the tropopause corresponded to the 198 mb level in the model.