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Cloud Analysis - Part 2

Region-to-Region Variations of Cloud and Surface Properties

When the cloud variations on time scales less than a month (weather) are removed, the largest remaining variations of clouds and surface properties occur from region-to-region and are constant in time. That is, once weather variabilty is removed the regional differences in average cloud properties are larger than the seasonal and slower climate variations. The figure below shows the time-averaged geographic pattern of cloud and surface properties as the Annual Mean Distributions averaged over the whole ISCCP dataset. Also shown to the right of each map is the average variation with latitude.

Figure 3: Annual Mean Distributions

CLOUD AMOUNT
Cloud Amount (%)
CLOUD TOP PRESSURE
Cloud Top Pressure (mb)
CLOUD TOP TEMPERATURE
Cloud Top Temperature (K)
CLOUD OPTICAL THICKNESS
Cloud Optical Depth
SURFACE TEMPERATURE
Surface Temperature (K)
SURFACE REFLECTANCE
Surface Reflectance

Cloud amount is high in the midlatitude storm tracks and in the convective zone in the tropics. The "desert" zone exhibits much less cloud amount. The regional cloud amount variations at low latitudes are much larger than at higher latitudes, but there is usually less cloud amount over land than ocean. The "stormy" zones are also shown by the regions that have lower cloud top pressures, colder cloud top temperatures and larger cloud optical thicknesses.


Part 1 | Part 2 | Part 3 | Part 4 | Part 5 | Part 6 | Part 7 | Part 8

Data Analysis