The atmosphere model output is provided on a 96x48 Gaussian grid
(approximately 3.75° lat
x 3.75° long). The
ocean model output is provided on a 192x96 grid (2x2 oceanic
grid boxes for each atmospheric grid box). Monthly data are available
from 5 runs for years 1850-2000. Daily data are available from 5 runs
for years 1961-2000. Daily data for several 2-D variables from the
first run are available for years 1850-2000.
The user should be aware that grid box values are not directly comparable to station data. Climate models attempt to represent the full climate system from first principles on large scales. Physical "parameterizations" are used to approximate the effects of unresolved small scale processes because it is not economically feasible to include detailed representations of these processes in present day models. Caution is therefore needed when comparing climate model output with observations or analyses on spatial scales shorter than several grid lengths (approximately 1000 to 1500 km in mid-latitudes), or when using model output to study the impacts of climate variability and change. The user is further cautioned that estimates of climate variability and change obtained from climate model results are subject to sampling variability. This uncertainty arises from the natural variability that is part of the observed climate system and is generally well simulated by the climate models.