The standard AVHRR Polar Pathfinder (APP) product includes gridded radiances, viewing and illumination geometry, clear sky surface temperature and albedo, and three cloud masks at a 5 km resolution. We have extended the standard APP product to include all-sky surface temperature, all-sky surface albedo, cloud information  (amount, type, particle phase, effective radius, optical depth, temperature and pressure), and radiative fluxes as well as cloud radiative effect ("forcing"). We refer to this dataset as APP-x.

The retrieval algorithms of the Cloud and Surface Parameter Retrieval ( CASPR) system were applied. The following parameters are available:
 

Surface and Clouds:

Radiation:

Surface temperature, clear or all-sky Broadband albedo, clear or all-sky Cloud particle effective radius Cloud optical depth Cloud particle phase Surface type mask Cloud top temperature Cloud top pressure Cloud type Precipitable water

Downwelling shortwave flux at the surface Downwelling longwave flux at the surface Upwelling shortwave flux at the surface Upwelling longwave flux at the surface Downwelling shortwave flux at the top of the atmosphere Upwelling shortwave flux at the top of the atmosphere Upwelling longwave flux at the top of the atmosphere Shortwave cloud forcing at the surface Longwave cloud forcing at the surface

The area of coverage for the Arctic and Antarctic are shown in the figures below.

Here are a few examples of the data set:

• Annual mean Arctic surface temperature
• Annual mean Antarctic surface temperature
• Annual mean Arctic net radiation flux at the surface
• Annual mean Antarctic net cloud forcing at the surface