TOVS Pathfinder Path-P Daily Arctic Gridded Atmospheric Parameters

Data Contributors

FRANCIS, JENNIFER A.
SCHWEIGER, AXEL J.

Parameters

AIR TEMPERATURE
CLOUD AMOUNT/FREQUENCY > EFFECTIVE CLOUD FRACTION
CLOUD TOP PRESSURE
CLOUD TOP TEMPERATURE
EMISSIVITY
PRECIPITABLE WATER
SKIN TEMPERATURE
SURFACE AIR TEMPERATURE
WIND STRESS > GEOSTROPHIC DRAG COEFFICIENT

Instruments

HIRS : HIGH RESOLUTION INFRARED RADIATION SOUNDER
MSU : MICROWAVE SOUNDING UNIT
SOUNDERS
TOVS : TIROS OPERATIONAL VERTICAL SOUNDER

The TIROS-N Operational Vertical Sounder (TOVS) Polar Pathfinder (Path-P) consists of gridded daily and monthly Arctic atmospheric data derived from various NOAA satellites. TOVS Path-P daily files are available for Northern and Southern Hemispheres (from 60° poleward) at 100 km gridded spatial resolution in an Equal-Area Scalable Earth Grid (EASE-Grid). Daily Northern Hemisphere data are available from July 1979 through December 2004, and Southern Hemisphere data are through December 2001. Monthly Northern Hemisphere data are available from July 1979 through December 2004. Data were created from a modified version of the Improved Initialization Inversion Algorithm (3I) (Chedin et al. 1985), a physical-statistical retrieval method improved for use in identifying geophysical variables in snow- and ice-covered areas (Francis 1994).

Variables retrieved from satellite-observed radiances for this product include atmospheric temperature, water vapor, skin surface temperature, total effective cloud fraction, cloud top pressure and temperature, solar zenith elevation, surface pressure, turning angle between geostrophic wind and surface stress over ice, emissivity, boundary layer stratification and geostrophic drag coefficient. The algorithm used to generate these grids has been validated through comparisons with surface observations from the North Pole drifting meteorological stations (Schweiger et al. 1999).

These data were developed at the University of Washington's Applied Physics Laboratory with funding from Polar Exchange at the Sea Surface (POLES), a NASA EOS interdisciplinary project. For validation updates, or more information on POLES or the TOVS Polar Pathfinder project please see the TOVS Polar Pathfinder Web site (http://psc.apl.washington.edu/pathp/).

The complete TOVS data set in Hierarchical Data Format (HDF) is available via FTP in compressed annual tar files. Users may also order subsets of the data for any of the parameters listed above, or for specific spatial or temporal coverage. Subsetted data are available in binary format only through the Graphical Interface for Subsetting, Mapping, and Ordering (GISMO).

Data users are encouraged to register before accessing the TOVS data. Registered users automatically receive release notes via e-mail containing notification of data manipulation or formatting modifications.

Data Citation

Francis, J., and A. Schweiger. 1999, updated 2006. TOVS Pathfinder Path-P daily arctic gridded atmospheric parameters. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.