The Level-3 MODIS Atmosphere Daily Global Product contains roughly 600 statistical datasets that are derived from approximately 80 scientific parameters from four Level-2 MODIS Atmosphere Products: Aerosol, Water Vapor, Cloud, and Atmosphere Profile. There are two MODIS Daily Global data product files: MOD08_D3, containing data collected from the Terra platform; and MYD08_D3, containing data collected from the Aqua platform.

A range of statistical summaries are computed, depending on the parameter being considered. Statistics for a given measurement might include:

• Simple (mean, minimum, maximum, standard deviation) statistics
• Parameters of normal and log-normal distributions
• Fraction of pixels that satisfy some condition (e.g. cloudy, clear)
• Histograms of the quantity within each grid box
• Histograms of the confidence placed in each measurement
• Histograms and/or regressions derived from comparing one science parameter to another, statistics may be computed for a subset that satisfies some condition

Statistics are sorted into 1 by 1 degree cells on an equal-angle grid that spans a 24-hour (0000 to 2400 Greenwich Mean Time) interval and then summarized over the globe. It should be noted that browse images (see links at left) are available in both the native equal-angle (lat-lon) grid as well as an equal-area (hammer-aitoff) grid.