Each document contains information about the type of data,
spatial characteristics, temporal characteristics, instrument
description, data processing sequence, quality assessment, contacts
for data production information, output products and availability,
data access, contacts, references and related data sets.
These data are processed in several stages by the principal participating national and international agencies: NASA, NOAA, European Space Agency, Japan Meteorological Agency, Canadian Atmospheric Environment Service, Centre de Meteorologie Spatiale, and Colorado State University. The sources for these data are the NOAA Polar Orbiting Satellites, Geostationary Operational Environmental Satellites (GOES), Geostationary Meteorological Satellites (GMS), and METEOSAT weather satellites from which visible and thermal infrared radiances are collected and analyzed. Originally retrieved radiances are first sampled at 30 km and three-hourly resolution and normalized in calibration by reference to the NOAA-7 Advanced Very High Resolution Radiometer (AVHRR). This data set is called the ISCCP Stage B3 (ISCCP-B3) data and has navigation and calibration information appended.
These data are then merged and analyzed at 280 km resolution, maintaining the three-hourly temporal resolution to become the ISCCP Stage C1 (ISCCP-C1) data set. Data are available for the hours 00, 03, 06, 09, 12, 15, 18, and 21 UTC for the given months. The NAVY/NOAA Snow/Ice products and the TOVS data are included and make up a portion of the 132 variables contained in ISCCP-C1.
The ISCCP-C1 products are then used to create the monthly statistics, at both three-hour-monthly and monthly temporal resolutions. The resulting products reside on this CD-ROM and are called the ISCCP-C2 data set. The variables include time and spatial means and standard deviations for cloud top pressure and temperature, cloud optical depth, and cloud water path. Optical depth, water path, cloud top pressure, cloud top temperature, and frequencies are available for low, middle, and high clouds and for cumulus, stratus, altocumulus, nimbostratus, cirrus, and deep convective clouds. Also offered as part of the C2 product are surface reflectance and snow/ice cover information. Variables derived from the TIROS Operational Vertical Sounder (TOVS) are precipitable water; surface, 500 mb, tropopause, and stratospheric temperatures; and surface and tropopause pressures. Variables derived from visible wavelengths are available only during daylight hours.