Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I Passive Microwave Data

Data Contributors

PARKINSON, CLAIRE L.
GLOERSEN, PER
ZWALLY, H. JAY
CAVALIERI, DONALD
MEIER, WALT
FETTERER, F.
KNOWLES, KENNETH W.
SAVOIE, MATTHEW H.
BRODZIK, MARY J.

Parameters

SEA ICE CONCENTRATION

Instruments

SMMR : SCANNING MULTICHANNEL MICROWAVE RADIOMETER
SSM/I : SPECIAL SENSOR MICROWAVE/IMAGER

This data set is generated from brightness temperature data derived from Nimbus-7 Scanning Multichannel Microwave Radiometer (SMMR) and Defense Meteorological Satellite Program (DMSP) -F8, -F11 and -F13 Special Sensor Microwave/Imager (SSM/I) radiances at a grid cell size of 25 x 25 km. The data are provided in the polar stereographic projection.

This product is designed to provide a consistent time series of sea ice concentrations (the fraction, or percentage, of ocean area covered by sea ice) spanning the coverage of several passive microwave instruments. To aid in this goal, sea ice algorithm coefficients are changed to reduce differences in sea ice extent and area as estimated using the SMMR and SSM/I sensors. The data are generated using the NASA Team algorithm developed by the Oceans and Ice Branch, Laboratory for Hydrospheric Processes at NASA Goddard Space Flight Center (GSFC).

These data include gridded daily (every other day for SMMR data) and monthly averaged sea ice concentrations for both the north and south polar regions. Two types of data are provided: final data and preliminary data. Final data are produced at GSFC about once per year, with roughly a one-year latency, and include data since 26 October 1978. Final data are produced from SMMR brightness temperature data processed at NASA GSFC and SSM/I brightness temperature data processed at the National Snow and Ice Data Center (NSIDC). Preliminary data are produced at NSIDC approximately every three months (quarterly), using SSM/I data acquired from Remote Sensing Systems, Inc. (RSS), and include roughly the most recent three to twelve months of processed data.

Data are scaled and stored as one-byte integers in flat binary arrays. For each data file, a corresponding PNG browse image file is provided. Data are available via FTP.

While the final and preliminary data are reasonably consistent, the particular type of data used for any publication, presentation, or other application should be clearly stated. The citation to use depends on whether final or preliminary data were used; if both were used, please cite each type.

Data Citation

These examples show how to cite these data (final or preliminary) in a publication. List investigators, release year, title, dates of data used, publisher (NSIDC), and media format.

Final
Cavalieri, D., C. Parkinson, P. Gloersen, and H. J. Zwally. 1996, updated 2008. Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data, [list dates used]. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.

Preliminary
Meier, W., F. Fetterer, K. Knowles, M. Savoie, M. J. Brodzik. 2006, updated quarterly. Sea ice concentrations from Nimbus-7 SMMR and DMSP SSM/I passive microwave data, [list dates used]. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.