International Satellite Cloud Climatology Project (ISCCP) Ice Snow Product in Native Data Format

ISCCP_ICESNOW_NAT_1 is the International Satellite Cloud Climatology Project (ISCCP) Ice Snow Product in Native Data Format data set. It is a merged product containing separate snow and sea ice data sets. The values given are fractional coverage for 5-day intervals. Data collection for this data set is complete. The data were collected on a global equal-area grid with the cell area equivalent to 1 degree latitude/longitude at the equator. The grid began at the South Pole with the intersection of the Greenwich meridian (0 degree longitude) and the South Pole as a cell corner. Ice/Snow Data Set contents included 5-day averages of snow and sea ice fractional coverage. Snow is deduced from visible satellite imagery plus ground data while sea ice was deduced from ship/shore and visible satellite imagery, and microwave measurements. ISCCP was the first project of the World Climate Research Program (WCRP), to collect and analyze satellite radiance measurements to infer the global distribution of cloud radiative properties and their diurnal and seasonal variations. These data and analysis products were used to improve the understanding and modeling of the effects of clouds on climate. The ISCCP version of the ice/snow data set included only information concerning fractional coverage. The version actually used in the cloud analysis was changed in two ways: reductions to ice/snow presence and creation of margin zones in the data. The first of these was simply the process of converting the coded parameters in the original data set to code values that indicate only the presence or absence of sea ice and/or snow. The latter process filled in nearby grid cells in the data to indicate proximity to snow or sea ice covered locations. The second change is not included in the archived version of this data.