Glenn H. White
This page presents a monthly mean climatology of cloud estimates from the International Satellite Cloud Climatology Project (ISCCP) averaged over 1984-90. Total, high, middle and low cloud amounts are given. In comparing this climatology to the NCEP global model's clouds, two factors should be remembered. First, the NCEP model's clouds are tuned to Air Force nephanalyses, not to ISCCP clouds. Air Force nephanalyses give a somewhat different picture of clouds than ISCCP and it is not known to me whether either set of clouds has been shown to be superior. ISCCP clouds do seem to be more widely used. Second, the division into high, middle and low may not be the same in ISCCP clouds and in the NCEP model. It is hoped that the ISCCP cloud patterns, if not always the magnitudes, will prove useful in improving the NCEP model's clouds. The standard deviations shown reflect the variability of a particular month form year to year. The zonal means are plotted with dashed lines representing the monthly mean plus or minus one standard deviation.