The MODIS Level-2 Cloud product consists of cloud optical and physical parameters. These parameters are derived using remotely sensed infrared, visible and near infrared solar reflected radiances. MODIS infrared channel radiances are used to derive cloud top temperature, cloud top height, effective emissivity, cloud phase (ice vs. water, opaque vs. non-opaque), and cloud fraction under both daytime and nighttime conditions. MODIS visible radiances are used to derive cloud optical thickness and effective particle radius and cloud shadow effects. Near-infrared solar reflected radiance provides additional information for the retrieval of cloud particle phase (ice vs. water, clouds vs. snow). The shortname for this Level-2 MODIS cloud product is MOD06_L2. MOD06_L2 consists of parameters at a spatial resolution of either 1km or 5km (at nadir). Each MOD06_L2 product file covers a 5-minute time interval. This means that for 5km resolution parameters, the output grid is 270 pixels wide by 406 pixels in length. Every tenth granule has an output grid size of 270 by 408 pixels. For 1-km resolution parameters, the output grid is 1354 pixels in width by 2030 pixels in length and every tenth granule has an output grid size of 1354 by 2040 pixels.
MOD06_L2 product files are stored in Hierarchical Data Format (HDF-EOS). All gridded cloud parameters are stored as Scientific Data Sets (SDS) within the file, except two (band number and statistics). These are stored as Vdata (table arrays). Approximately 288 files are produced daily. Nighttime files are smaller than their daytime counterparts since only the cloud top properties are retrieved at night.
The MODIS Cloud Product will be used to investigate seasonal and inter-annual changes in cirrus (semi-transparent) global cloud cover and cloud phase with multispectral observations at 1km spatial resolution.
For additional details see the MODIS Atmospheres web site page on Collection 6.1 Updates.