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    SSM/I is the first operational passive microwave imaging sensor to provide routine, daily, all-weather sea ice observations in near-real time. Launch of the DMSP F-8 satellite carrying the first SSM/I was 20 June 1987.The primary archive and distribution source for SSM/I swath (orbital) data (level 1b) is NOAA/NESDIS/SDSD, 100 Princeton Executive Center, Washington, DC 20233; telephone (301) 763-8402. NSIDC distributes SSM/I data products on CD-ROM. NSIDC uses orbital antenna temperature data to produce gridded brightness temperatures (Tb) for the polar regions. The grid has a resolution of 12.5 km for the 85 GHz channels, and 25 km for the 19, 22, and 37 GHz channels. PC-compatible software is provided to extract the Tb from the CD-ROM, to calculate ice concentration at 50 km resolution from the Tb data, and to display the images on a PC or a Macintosh.As of December 1990, eight CD-ROM discs have been produced, containing gridded brightness temperatures for north and south polar regions for 9 July 1987 through 30 June 1989. Each CD-ROM contains approximately 3 months of data. Additional discs will be released as they are completed. Please inquire for current availability. Specify PC or Macintosh platform preference ( or both.) The SSM/I archive at NSIDC includes the data sets listed below. Small amounts of data (limited in time and geographic extent) are available on magnetic tape. There is a $40 minimum charge per order for data on tape. Please contact NSIDC with your requirements.1. Rapid Access (SDR) Archive, containing sensor data records of swath data used to produce the three other data sets listed below. [Not available on CD-ROM.]2. Daily Gridded Brightness Temperatures at 12.5 km resolution for North and South Polar regions from 85.5 GHz (0.35 cm) channels, horizontal and vertical polarization. [Distributed on CD-ROM.]3. Daily Gridded Brightness Temperatures at 25.0 km resolution for North and South Polar regions from 19.35 GHz (0.35 cm), 22.235GHz (1.35 cm), and 37.0 GHz (0.81 cm) channels, horizontal and vertical polarization. [Distributed on CD-ROM.]4. First-year, Multi-year, and Total Ice Concentration on 50 km resolution daily grids for North and South Polar regions. [Software is provided to calculate; may be distributed on CD-ROM in the future.]National Snow and Ice Data Center (1990) DMSP SSM/I Brightness and Temperature Grids for the Polar Regions on CD-ROM. User's Guide. NSIDC, Boulder, CO. Looseleaf. This guide is provided with each set of SSM/I CD-ROMs. A complete list of references is provided on request.

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    Since August of 1993, NSIDC has been collecting and archiving a bi-polar data set of 1-km HRPT and LAC AVHRR imagery from HRPT receiving stations at McMurdo, Palmer, Fairbanks, Prince Albert, and Tromso, and from recorded and rebroadcast LAC images for both polar regions. Most of the data are obtained as a polar subset of the Global Land 1-km AVHRR Data Set currently collected and distributed by the EROS Data Center (EDC). The Antarctic HRPT data are collected by Scripps Institution of Oceanography. Combined, these two data sets provide nearly complete coverage of both poles' sea ice, land ice, and polar lands, at nearly 1-km resolution, and for all 5 bands of the AVHRR sensor. The time range of the archive extends from April, 1992 to the present for the southern hemisphere, and from August 1993 to the present for the northern hemisphere. As of 8/1/94, the archive contains 5000 scenes.Image data are available for general distribution in the NOAA Level 1b"packed" format. A catalog of archived scenes, with information on location, time of acquisition, image size, and data quality, may be obtained on request. This will allow potential users of the data set to see what areas are covered, and how frequently they are covered. A browse data set for each image is installed on the NSIDC optical jukebox; this will be made accessible via Internet in the near future. A test data set, consisting of all archived acquisitions for 31 August - 2 September 1993 over the Northern Hemisphere is available on 8mm tapes. This data set is intended to allow interested parties to evaluate the usefulness of the collected data for various applications.To receive a copy of the catalog or test data set, contact NSIDC User Services (nsidc@kryos.colorado.edu or nsidc@eos.nasa.gov via Internet; 303-492-6199 voice; 303-492-2468 fax). For more information on scientific applications of the data, contact Ted Scambos at NSIDC (teds@icehouse.colorado.edu via Internet; 303-492-1113 voice; 303-492-2468 fax). References: Hastings, D. A. and W. J. Emery, Advanced Very High Resolution Radiometer (AVHRR): A Brief Reference Guide. Photogrammetric Engineering and Remote Sensing, 58(8), 1992, pp. 1183-1188. Kidwell, K.B. NOAA Polar Orbiter Data Users Guide (TIROS-N, NOAA-6, NOAA-7, NOAA-8, NOAA-10, NOAA-11, and NOAA-12) NOAA, NESDIS, 1991. Planet, W.D. (ed.) Data extraction and calibration of TIROS-N/NOAAradiometers. NOAA Technical Memorandum NESS 107, rev. 1, 1988, 58 pp.plus appendices. Steffen, K., R. Bindschadler, G. Casassa, J. Comiso, D. Eppler, F. Fetterer, J. Hawkins, J. Key, D. Rothrock, R. Thomas, R. Weaver, R. Welch, Snow and ice applications of AVHRR in polar regions: report of a workshop held in Boulder, Colorado, 20 May 1992. Annals of Glaciology.17, 1993, pp. 1-15.

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    The 'high resolution' land/sea tag data base provides high density coverage of the worlds 'coastal interfaces', i.e. its shorelines. The search radius about each grid point is 5 km, providing 10 km resolution. The file is organized into blocks of data for areas 10 degrees on a side. Areas which are all land or all sea have a directory entry but no data record. If a circular area of 5 km radius about a grid point has any land in it whatsover, it is designated land. Grid points are spaced 1/16 degree apart so that 1 degree's worth of information in longitude can be exactly packed in 2 bytes, A 10 degree square therefore uses 25,600 bits or 3200 bytes of storage.At the equator, grid points are spaced about 6.96 km apart. A 5 km search radius encompasses all the area which can be assigned to any given grid point. The maximum number of 10 degree square areas on the Earth is 648, but far fewer should be needed. Fitting 3 3200-byte areas onto a track calls for a maximum of 217 tracks, including the directory record.

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    A global grid of 'low resolution' land/sea tags is maintained and used both to check AVHRR targets and to determine at which grid points SST field temperatures will be maintained. The resolution of these tags is 28 and 50 km centered on the grid point. The grid spacing is 1/2 degree between 85N and 85S. The file is divided into 3 regions, each two records long with some overlap of regions to minimize the number of reads necessary in target processing. The regions are as follows: 1) 85S-25S, 2) 30S to 30N, and 3) 25N-85N. The polar regions are considered to be perpetually ice-covered and no SST targets in these regions will be processed.

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    Thesis

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    Maturity stage, egg stage, stage of atresia, largest oocyte diameter of Atka mackerel. Sampled from 1992 - 1994 in Aleutian Islands. Historical slides also available. Data include haul information and location in the NMFS survey format.Reference: By Susanne F. McDermott and Sandra A. Lowe) (Fish. Bull., U.S. 95(2):321-333

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    LANDSAT and NOAA satellite images from the University of Alaska LANDSAT Library have been used to make maps of ice conditions in the eastern Bering Sea. The analyses included daily charts of the ice, polynya locations, floe trajectories and comparisons between data taken from the two sources. A Zoom Transfer Scope (ZTS) was used to transfer the data from an image to a map base for late winter conditions in 1974, 1976, 1977 and 1979.[Reference: McNutt, S.L. (1981): Ice conditions in the Eastern Bering Sea from NOAA and LANDSAT imagery: Winter conditions 1974, 1976, 1977, 1979. NOAA Tech. Memo. ERL PMEL-24 (PB81-220188), 179 pp. ]

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    Summary Defense Meteorological Satellite Program Satellites (DMSP) Special Sensor Microwave Imager (SSM/I) F11 daily, total and multi-year sea ice concentration grids are derived from the SSM/I daily brightness temperatures. With a resolution of 25X25 km, these sea ice concentrations are presented as raster images (HDF raster image sets, RIS) mapped to polar stereographic projections depicting north and south polar regions.Data are stored in HDF and packaged in compressed tar format. These ice concentrations continue the series begun with DMSP-F8 SSM/I coverage, generated using the NASA Team algorithm. Processing is continuous on the F11 data, beginning 3 December 1991. The DMSP-F8 and -F11 data demonstrate a high degree of correlation (Abdalati et al. 1995) although regression coefficients are applied in the development of F11 ice concentrations in order to maintain consistency of the data set (NSIDC 1995). Data are available via ftp (sidads.colorado.edu, IP address 128.138.135.20). End_group Group: QualityData are routinely inspected and undergo extensive quality control procedures. Please see DMSP SSM/I Brightness Temperatures and Sea Ice Concentration Grids for the Polar Regions, User's Guide, (NSIDC 1995) for details on data set correlation, geo-location n errors and antenna pattern correction procedures performed on the data, and for more information on the NASA Team algorithm and weather filter. References: Abdalati, W., K. Steffen, C. Otto and K. C. Jezek. 1995. Comparison of brightness temperatures from SSM/I instruments on the DMSP F8 and F11 satellites for Antarctic and the Greenland Ice Sheet. International Journal of Remote Sensing. In press. Cavalieri, D.J., P. Gloersen and W.J. Campbell, Determination of sea ice parameters with the NIMBUS-7 SMMR. J. Geophys. Res., 89(D4), p. 5355-5369, 1984. National Snow and Ice Data Center, DMSP SSM/I Brightness Temperature and Ice Concentration Grids for the Polar Regions. User's Guide. National Snow and Ice Data Center. Special Publication NSIDC SP-1. Boulder, Colorado, looseleaf, 1990, rev. 1994 in preparation.

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    The algorithm used to generate these grids has been validated directly through comparisons with surface observations from the CEAREX experiment and with radiosonde data from Soviet ice stations. Comparisons with other TOVS retrieval algorithms provided further validation. Validation is on-going and information will be updated as appropriate.Gridded Arctic atmospheric and surface parameters north of 60 degrees North from NCAR's NOAA-10 TOVS HIRS and MSU level-1b radiances using "Improved Iteration Inversion Algorithm" (3I, Chedin 1985). Grids are 100 km X 100 km, 1 April 1987 - 31 October 1988, the Pathfinder benchmark period. Daily data are linear averages of all orbits for one day, 00:00:00 GMT to (excluding) 00:00:00 GMT of the following day. Monthly data are linear averages of all orbits from 00:00:00 GMT of day 1 of a month to 00:00:00 GMT of the last day of that month. Monthly averages directly from orbital data, not averaged daily data. Grid uses equal area azimuthal projection centered on North Pole, is a version of the Equal Area SSM/I Earth (EASE) grid under development at NSIDC. Path_P products are in Hierarchical Data Format (HDF version 3.3r3). Data available on 4 mm DAT tape, 8mm cartridges and via FTP. NSIDC maintains on-line documentation for this data set. Users may access the NSIDC DAAC via the World Wide Web at: http://www-nsidc.colorado.edu/NASA/GUIDE References: Chedin, A., N. A. Scott, C. Wahiche and P. Moulinier. 1985. The Improved Initialization Inversion Method: A high resolution physical method for temperature retrievals from satellites of the TIROS-N series. Journal of Climate and Applied Meteorology. 24:128-143. Francis, J. A. 1994. Improvements to TOVS retrievals over sea ice and applications to estimating Arctic energy fluxes. Journal of Geophysical Research. 99(D5):10,395-10,408. Goddard Space Flight Center. 1994. EOSDIS Version 0 Data Product Implementation Guidelines. Draft Version 1.0 (March 1, 1994). GSFC 50-003-04. GSFC. Greenbelt, MD. National Center for Supercomputing Applications. 1993. HDF Calling Interfaces and Utilities. Version 3.22. University of Illinois at Urbana-Champaign. National Center for Supercomputing Applications. 1994. HDF Reference Manual. Version 3.3. University of Illinois at Urbana-Champaign. Schweiger, A. and Francis, J. 1994. TOVS Pathfinder Path-P Gridded Daily and Monthly Arctic Atmospheric Data from TOVS, User's Guide. Draft version 0.1. University of Washington, Seattle.

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    Satellite imagery from 1991 to present (and continuing). Some historical (pre-1991) data exist.