But it's white noise, so
averaged over a reasonable period of time, the amount of water is fairly constant.
Not exact matches
The difference between the full F3 (AGW) and truncated F3 (AGW) is, however, barely visible, when the weighted
average is used for both
time and anomaly, because the AGW is close enough to linear
over the
period of 22 years which is the full width at half maximum
of the impulse response and thus a
reasonable measure
of the effective
period for calculating the weighted
average.
Due to the sensitivity on initial values also within limits
of reasonable agreement with real weather patterns at a specific moment
of time, the interesting results come from
averages over many model runs or
over long enough
periods to remove the dependence on initial values.
If cloud changes are associated with natural internal variability which the: models generally consider «unforced variations» then I guess we can pretend that variability
averages to zero
over a
reasonable time frame and ignore it as noise, even though we are not particularly sure what is a
reasonable period of time in climate.