Abstract:
This sea ice concentration data set was derived using measurements from the Scanning Multichannel Microwave Radiometer (SMMR) on the Nimbus-7 satellite and from the Special Sensor Microwave/Imager (SSM/I) sensors on the Defense Meteorological Satellite Program's (DMSP) -F8, -F11, and -F13 satellites. Measurements from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard DMSP-F17 are also ... included. The data set has been generated using the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Bootstrap Algorithm with daily varying tie-points. Daily (every other day prior to July 1987) and monthly data are available for both the north and south polar regions. Data are gridded on the SSM/I polar stereographic grid (25 x 25 km) and provided in two-byte integer format. Data are available via FTP. Important: The most recent revision (Version 2, released September 2007) has tie-points adjusted to be consistent with the AMSR-E Bootstrap algorithm. This involved a complete reprocessing of the entire SMMR-SSM/I time series. Because Version 2 is inter-calibrated with AMSR-E, it is NOT consistent or compatible with the original version of this data set (Version 1). Users should acquire the entire Version 2 data set in order to update their time series.
Quality
Although most bad data are easily identifiable and removed with little ambiguity, human judgments must be made and applied consistently to the time series data. While efforts were made to minimize errors in judgment and inconsistencies, the resulting data set is not perfect. Nevertheless, the data provider feels that these maps are suitable for some types of research studies, such as basin-scale ... trend analysis, model inputs, and some regional studies. They are less useful in evaluating conditions on a specific day in a localized region. NSIDC staff visually checked the entire set of data files, including file structure, comparisons to existing SMMR- and SSM/I-derived sea ice concentration grids, and information files and examination of data quality. Please note that in this document, a large fraction of the text was supplied by the data set provider. It may include qualitative judgments and statements by the provider and does not necessarily represent endorsements or imply that independent assessments have been performed by NSIDC staff. Limitations of the Data Basic limitations arise from the sensor resolution, temporal coverage, and algorithm assumptions and characteristics. Users should review the information provided on fields of view, temporal sampling, and algorithm characteristics. Particular care is needed in interpreting the sea ice concentrations during summer when melt is underway and in regions where new sea ice makes up a substantial part of the sea ice cover. As noted, some residual errors remain due to sensor differences and to weather effects along with mixing of ocean and land area within the sensor field of view. No data coverage is available for regions poleward of 81° N for SMMR and 87° N for SSM/I due to the inclination of the orbits. SMMR data were acquired every other day, while SSM/I data are acquired daily.
Laboratory for Hydrospheric Processes
Cryospheric Sciences Branch
NASA/Goddard Space Flight Center
Code 614
City:
Greenbelt
Province or State:
MD
Postal Code:
20771
Country:
USA
Publications/References
Cho, K., N. Sasaki, H. Shimoda, T. Sakata, and F. Nishio. 1996. Evaluation and Improvement of SSM/I Sea Ice Concentration Algorithms for the Sea of Okhotsk. Journal Remote Sensing of Japan 16(2):47-58.
Comiso, J. C., and F. Nishio. 2008. Trends in the Sea Ice Cover Using Enhanced and Compatible AMSR-E, SSM/I, and SMMR Data. Journal of Geophysical Research 113, C02S07, doi:10.1029/2007JC0043257. ...
Comiso, J. C., D. Cavalieri, C. Parkinson, and P. Gloersen. 1997. Passive Microwave Algorithms for Sea Ice Concentrations: A Comparison of Two Techniques. Remote Sensing of the Environment 60(3):357-84.
Comiso, J. C., and R. Kwok. 1996. The Summer Arctic Sea Ice Cover from Satelli Observations. Journal of Geophysical Research 101(C2):28,397-416.
Comiso, J. C. 1995. SSM/I Concentrations Using the Bootstrap Algorithm. NASA Reference Publication 1380. 40 pages.
Comiso, J. C, T. C. Grenfell, M. Lange, A. Lohanick, R. Moore, and P. Wadhams. 1992. Microwave Remote Sensing of the Southern Ocean Ice Cover. Microwave Remote Sensing of Sea Ice, ed. Frank Carsey. Washington D.C.: American Geophysical Union. 243-59.
Comiso, J. C. and C. W. Sullivan. 1986. Satellite Microwave and In-Situ Observations of the Weddell Sea ice Cover and its Marginal Ice Zone. Journal of Geophysical Research 91(C8):9,663-81.
Comiso, J. C. 1984. Characteristics of Winter Sea Ice from Satellite Multispectral Microwave Observations. Journal of Geophysical Research 91(C1):975-94.
Comiso, J. C., S. F. Ackley, and A. L. Gordon. 1984. Antarctic Sea Ice Microwave Signature and Their Correlation with In-Situ Ice Observations. Journal of Geophysical Research 89(C1):662-72.
Gloersen P., W. Campbell, D. Cavalieri, J. Comiso, C. Parkinson, H. J. Zwally. 1992. Arctic and Antarctic Sea Ice, 1978-1987: Satellite Passive Microwave Observations and Analysis. NASA Special Publication 511.
Maslanik, J. A. 1992. Effects of Weather on the Retrieval of Sea Ice Concentration and Ice Type from Passive Microwave Data. International Journal of Remote Sensing 13(1):37-54.
National Snow and Ice Data Center. 1992. DMSP SSM/I Brightness Temperature and Sea Ice Concentration Grids for the Polar Regions on CD-ROM - User's Guide. NSIDC Special Report - 1. 222 pp.
Parkinson, C. L., D. J. Cavalieri, P. Gloersen, H. J. Zwally, and J. C. Comiso, 1999. Arctic Sea Ice Extents, Areas, and Trends, 1978-1996. Journal of Geophysical Research 104(C9), 20,837-20,856.
Parkinson, C. L., J. C. Comiso, H. J. Zwally, D. J. Cavalieri, P. Gloersen, and W. J. Campbell. 1987. Arctic Sea Ice 1973-1976 from Satellite Passive Microwave Observations. NASA Special Publication 489.
Pearson, F. 1990. Map Projections: Theory and Applications. Boca Raton, FL:CRC Press. 372 pages.
Snyder, J. P. 1987. Map Projections - A Working Manual. U.S. Geological Survey Professional Paper 1395. Washington, D.C.:U.S. Government Printing Office. 383 pages.
Snyder, J. P. 1982. Map Projections used by the U.S. Geological Survey. U.S. Geological Survey Bulletin 1532.
Zwally, H. J., J. C. Comiso, C. L. Parkinson, W. J. Campbell, F. D. Carsey, and P. Gloersen. 1983. Antarctic Sea Ice 1973-1976 from Satellite Passive Microwave Observations. NASA Special Publication 459.
