Metadata:
  Identification_Information:
    Citation:
      Citation_Information:
        Originator:
          Kenneth S. Casey, National Oceanic and Atmospheric Administration (NOAA) National
          Oceanographic Data Center (NODC)
        Originator:
          Edward J. Kearns, University of Miami, Rosenstiel School of Marine and
          Atmospheric Science (RSMAS)
        Originator: Vicki Halliwell, University of Miami, RSMAS
        Originator: Robert Evans, University of Miami, RSMAS
        Publication_Date: 200412
        Title: Seasonal Sea Surface Temperature Averages, 1985-2001
        Geospatial_Data_Presentation_Form: Map
        Publication_Information:
          Publication_Place: Silver Spring, MD
          Publisher: NOAA National Oceanographic Data Center
        Online_Linkage: <http://www.nodc.noaa.gov/sog/>
        Online_Linkage: <http://nationalatlas.gov/atlasftp.html?openChapters=chpclim#chpclim>
    Description:
      Abstract:
        This data set consists of four images showing seasonal sea surface temperature
        (SST) averages for the entire earth.  Data for the years 1985-2001 are averaged to
        produce each seasonal image.  The seasons are January-March (sst001i4km.tif),
        April-June (sst002i4km.tif), July-September (sst003i4km.tif), and October-December
        (sst004i4km.tif).

        These SST data are the result of the 4 km Pathfinder effort at the National Oceanic
        and Atmospheric Administration (NOAA) National Oceanographic Data Center (NODC) and
        the University of Miami's Rosenstiel School of Marine and Atmospheric Science
        (RSMAS), which uses data from the NOAA-9, NOAA-11, NOAA-14, and NOAA-16 satellites.
        The 4 km Pathfinder effort at NODC is an improvement to the original Pathfinder
        program, which was jointly developed by the National Aeronautics and Space
        Administration (NASA) and NOAA to provide long-term, consistently calibrated global
        change data sets to Earth scientists.  One of the data sets selected for the
        Pathfinder project was collected by the Advanced Very High Resolution Radiometer
        (AVHRR), a scanning radiometer flying onboard polar orbiters operated by NOAA.  The
        original AVHRR Pathfinder Program involved four separate elements: Atmosphere,
        Land, Oceans, and Calibration.  The objective of the AVHRR Oceans Pathfinder was to
        develop a long and consistent time series of global sea surface temperature (SST)
        fields.  The Pathfinder Project at NODC carries on this objective.

        The files for each season, also known as seasonal climatologies, are available both
        as 16-bit (pixel values from 0 to 65535) Hierarchical Data Format (.HDF) data files
        and as 8-bit (pixel values from 0 to 255) GeoTIFF images.

        This data set is also referred to as 4 km NODC/RSMAS AVHRR Pathfinder v.5.0
        Seasonal Climatologies (1985-2001).

      Purpose:
        These data are intended for geographic display and analysis at global, national,
        and local levels.  The data should be used at scales appropriate to 4 km resolution
        data.  No responsibility is assumed by the National Oceanic and Atmospheric
        Administration or the National Atlas of the United States in the use of these data.

      Supplemental_Information:
        The data displayed in the Map Maker of the National Atlas of the United States
        <http://nationalatlas.gov/natlas/Natlasstart.asp> have been clipped to the standard
        National Atlas extent, masked using a National Atlas land/water mask, and projected
        to a Lambert Azimuthal Equal Area projection.  The distributed data represent the
        global data set rather than the clipped and projected version available for viewing
        through the National Atlas.

        SST is a difficult parameter to define exactly because the upper ocean (~10 m) has
        a complex and variable vertical temperature structure that is related to ocean
        turbulence and the air-sea fluxes of heat, moisture and momentum.  Definitions of
        SST provide a necessary theoretical framework that can be used to understand the
        information content and relationships between measurements of SST made by different
        instruments.  The following explanatory statements attempt to provide this
        framework and encapsulate the effects of the dominant heat transport processes and
        time scale of variability associated with distinct vertical and volume regimes
        within a vertical element of the water column (horizontal and temporal variability
        is implicitly assumed):

        > The interface SST, SSTint, is the temperature of an infinitely thin layer at the
        > exact air-sea interface.  It represents the temperature at the top of the SSTskin
        > temperature gradient (layer) and cannot be measured using current technology.
        > It is important to note that it is the SSTint that interacts with the atmosphere.

        > The skin SST, SSTskin, is a temperature measured within a thin water layer (<500
        > micrometer) adjacent to the air-sea interface.  It is where conductive, diffusive
        > and molecular heat transfer processes dominate.  A strong vertical temperature
        > gradient is characteristically maintained in this thin layer sustained by the
        > magnitude and direction of the ocean-atmosphere heat flux.  Thus, SSTskin varies
        > according to the actual measurement depth within the layer.  This layer provides
        > the connectivity between a turbulent ocean and a turbulent atmosphere.

        > The sub-skin SST, SSTsub-skin, is representative of the SST at the bottom of the
        > surface layer where the dominance of molecular and conductive processes gives way
        > to turbulent heat transfer.  It varies on a time scale of minutes and is
        > influenced by solar warming in a manner strongly dependent on the turbulent
        > energy density in the layer below.

        > The near surface ocean temperature (~10 m) is significantly influenced by local
        > solar heating and typically varies with depth over a time scale of hours.
        > Consequently "SST" measurements should always be referenced against a specific
        > depth or an average over a depth range.  The notation SSTdepth  refers to any
        > temperature within the water column beneath the SSTsub-skin where turbulent heat
        > transfer processes dominate.  The traditional "bulk" SST is related to this
        > measure.  SSTdepth should always be quoted at a specific depth in the water
        > column; e.g., SST1m refers to the SST at a depth of 1m.

        > The SSTskin is the closest parameter actually measured by the AVHRR satellite
        > radiometer.  However, because the Pathfinder algorithm regresses the satellite-
        > observed radiances against buoy temperatures to determine a "bulk" SST, the
        > actual SST is akin to the SSTdepth where depth is about 1 m.

        The current 4 km data set is an extension of and improvement on the SST fields from
        the AVHRR Oceans 9 km Pathfinder data set
        (<http://www.rsmas.miami.edu/groups/rrsl/pathfinder/index.html>).  Some important
        shortcomings in the original 9 km data have been corrected, and the entire time
        series has been reprocessed at the 4 km Global Area Coverage (GAC) level, currently
        the highest resolution possible globally.  In addition, several enhancements have
        been made that increase the usefulness of the SST fields, including the use of sea
        ice in the quality level determination scheme, inclusion of many inland water
        bodies, and the use of a greatly improved land mask.  The greatest improvements are
        seen in coastal zones, marginal seas, and boundary current regions where SST
        gradients are often large and their impact on operational or research products is
        greatest.

        The data set was produced from 1985-2001 data using the Version 5.0 Pathfinder
        algorithm.  Version 5.0 is an improved version of the previously-most-successful of
        the many methods used to derive SST from AVHRR observations.  For more detail on
        this version of the Pathfinder data, a description of the processing algorithm, and
        a comparison of version 5 and version 4, please see the 4 km Pathfinder Version 5.0
        User Guide at <http://www.nodc.noaa.gov/sog/pathfinder4km/userguide.html>.

        Relative to the older 9 km v4.2 Pathfinder data, the new, ~4 km-resolution
        Pathfinder Version 5.0 global SSTs increase detail roughly by a factor of four
        simply by virtue of the increased resolution.  The increase in detail over widely
        used but relatively coarse SST datasets such as Optimally Interpolated SST
        Version 2 (Reynolds et al., 2002, <http://ams.allenpress.com/amsonline/
        ?request=get-abstract&issn=1520-0442&volume=015&issue=13&page=1609>) and the Hadley
        Centre's Global Sea Ice and SST (Rayner et al., 2003,
        <http://www.agu.org/pubs/crossref/2003/2002JD002670.shtml>) is far greater.

        The University of Miami Pathfinder version v4.2 SST algorithm is fully described in
        Kilpatrick et al., (2001).
        <http://www.agu.org/pubs/crossref/2001/1999JC000065.shtml>.  The v4.2 algorithm
        offered marked improvement over operational retrieval algorithms such as multi-
        channel sea surface temperature (MCSST) and was applied to AVHRR data to maximize
        accuracy and to minimize artificial fluctuations arising from the sequence of AVHRR
        instruments flown on NOAA's polar-orbiting satellites during the past 2 decades.
        The 9 km v4.2 Pathfinder SSTs were shown to be the highest quality product then
        available for the construction of global climatologies (Casey and Cornillon, 1999,
        <http://ams.allenpress.com/amsonline/?request=get-abstract&issn=1520-0442&volume=
        12&issue=6&page=1848>) and longer-term SST trend determination (Casey and
        Cornillon, 2001, <http://ams.allenpress.com/amsonline/?request=get-abstract&issn=
        1520-0442&volume=14&issue=18&page=3801>), and have been demonstrated to be accurate
        within about 0.3 degrees C under optimal conditions (Kearns et al., 2000,
        <http://ams.allenpress.com/pdfserv/i1520-0477-081-07-1525.pdf>).

        For a detailed description of the Version 4.0 Pathfinder SST algorithm, please see
        <http://www.rsmas.miami.edu/groups/rrsl/pathfinder/Algorithm/algo_index.html>.

        For a review of earlier techniques, see Barton (1995).
        <http://www.agu.org/pubs/crossref/1995/95JC00365.shtml>

        For more information on AVHRR, see <http://eros.usgs.gov/guides/avhrr.html> and
        <http://nationalatlas.gov/articles/mapping/a_avhrr.html>.

        The NOAA Polar Orbiter Data User's Guide describes the orbital and spacecraft
        characteristics, instruments, data formats, etc. of the TIROS-N, and NOAA-6 through
        NOAA-14 polar orbiter series of satellites.  See
        <http://www2.ncdc.noaa.gov/docs/podug/> for more information.

        A text file containing a complete source bibliography for this data set and
        suggested additional reading is bundled with the downloadable data. The file is
        called sstalli_biblio.txt.

        The following parameters are used for the GeoTIFF:
        >Version: 1
        >Key_Revision: 1.0
        >
        >Tagged_Information:
        >ModelTiepointTag (2,3):
        >0                0                0
        >-180             90               0
        >ModelPixelScaleTag (1,3):
        >0.0439453      0.0439453      0
        >End_Of_Tags.
        >
        >Keyed_Information:
        >GTModelTypeGeoKey (Short,1): ModelTypeGeographic
        >GTRasterTypeGeoKey (Short,1): RasterPixelIsArea
        >GTCitationGeoKey (Ascii,17): "LONG/LAT    E005"
        >GeographicTypeGeoKey (Short,1): GCS_WGS_84
        >GeogAngularUnitsGeoKey (Short,1): Angular_Degree
        >ProjLinearUnitsGeoKey (Short,1): Linear_Meter
        >End_Of_Keys.
        >End_Of_Geotiff.
        >
        >GCS: 4326/WGS 84
        >Datum: 6326/World Geodetic System 1984
        >Ellipsoid: 7030/WGS 84 (6378137.00,6356752.31)
        >Prime Meridian: 8901/Greenwich (0.000000/  0d 0' 0.00"E)
        >
        >Projection Linear Units: 9001/metre (1.000000m)
        >Corner Coordinates:
        >Upper Left    (180d 0' 0.00"W, 90d 0' 0.00"N)
        >Lower Left    (180d 0' 0.00"W, 90d 0' 0.00"S)
        >Upper Right   (180d 0' 0.00"E, 90d 0' 0.00"N)
        >Lower Right   (180d 0' 0.00"E, 90d 0' 0.00"S)
        >Center        (  0d 0' 0.00"E,  0d 0' 0.00"N)

        The associated world file is included as part of the GeoTIFF.  The
        contents of the world file are:
        >0.0439
        >0.000000
        >0.000000
        >-0.0439
        >-180.0000
        >90.0000
    Time_Period_of_Content:
      Time_Period_Information:
        Range_of_Dates/Times:
          Beginning_Date: 19850101
          Ending_Date: 20011231
      Currentness_Reference: Dates of source data
    Status:
      Progress: Complete
      Maintenance_and_Update_Frequency: As needed
    Spatial_Domain:
      Bounding_Coordinates:
        West_Bounding_Coordinate: -180
        East_Bounding_Coordinate: 180
        North_Bounding_Coordinate: 90
        South_Bounding_Coordinate: -90
    Keywords:
      Theme:
        Theme_Keyword_Thesaurus: Global Change Master Directory
        Theme_Keyword: Earth science
        Theme_Keyword: Biosphere
        Theme_Keyword: Coastal habitat
        Theme_Keyword: Aquatic habitat
        Theme_Keyword: Reef habitat
        Theme_Keyword: Climate indicators
        Theme_Keyword: Hydrosphere
        Theme_Keyword: Water quality
        Theme_Keyword: Water temperature
        Theme_Keyword: Oceans
        Theme_Keyword: Coastal processes
        Theme_Keyword: Coral reefs
        Theme_Keyword: Ocean temperature
        Theme_Keyword: Sea surface temperature
        Theme_Keyword: AVHRR
        Theme_Keyword: 4km Pathfinder
        Theme_Keyword: 9km Pathfinder
      Theme:
        Theme_Keyword_Thesaurus: ISO 19115 Topic Category
        Theme_Keyword: oceans
      Theme:
        Theme_Keyword_Thesaurus: None
        Theme_Keyword: Multi-channel sea surface temperature
        Theme_Keyword: MCSST
        Theme_Keyword: Non-linear sea surface temperature
        Theme_Keyword: NLSST
        Theme_Keyword: Seasonal climatologies

      Place:
        Place_Keyword_Thesaurus: None
        Place_Keyword: Atlantic Ocean
        Place_Keyword: Indian Ocean
        Place_Keyword: Mediterranean Sea
        Place_Keyword: North Atlantic Ocean
        Place_Keyword: North Pacific Ocean
        Place_Keyword: Pacific Ocean
        Place_Keyword: South Atlantic Ocean
        Place_Keyword: South Pacific Ocean
        Place_Keyword: Southern Ocean

    Access_Constraints: None
    Use_Constraints:
      Please acknowledge the use of these data with "The Pathfinder Version 5.0 SST Data
      were produced by the NOAA/National Oceanographic Data Center and are available from
      http://www.nodc.noaa.gov/sog/ or
      http://nationalatlas.gov/atlasftp.html?openChapters=chpclim#chpclim."

    Point_of_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Dr. Kenneth S. Casey
          Contact_Organization: NOAA/NESDIS National Oceanographic Data Center
        Contact_Address:
          Address_Type: Mailing address
          Address: NOAA/NESDIS National Oceanographic Data Center
          Address: SSMC3, 4th Floor, Room 4853, Route: E/OC1
          Address: 1315 East-West Highway
          City: Silver Spring
          State_or_Province: MD
          Postal_Code: 20910
          Country: USA
        Contact_Voice_Telephone: 301-713-3272 x133
        Contact_Facsimile_Telephone: 301-713-3300
        Contact_Electronic_Mail_Address: Kenneth.Casey@noaa.gov
        Hours_of_Service: 9:00 AM - 4:00 PM, Eastern time
    Browse_Graphic:
      Browse_Graphic_File_Name: <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology/season1_combined.tif>
      Browse_Graphic_File_Description: An image of the global data set of 1985-2001 averaged SST (January to March).
      Browse_Graphic_File_Type: GeoTIFF
    Browse_Graphic:
      Browse_Graphic_File_Name: <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology/season2_combined.tif>
      Browse_Graphic_File_Description: Image of global data set of 1985-2001 averaged SST (April to June)
      Browse_Graphic_File_Type: GeoTIFF
    Browse_Graphic:
      Browse_Graphic_File_Name: <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology/season3_combined.tif>
      Browse_Graphic_File_Description: Image of global data set of 1985-2001 averaged SST (July to September)
      Browse_Graphic_File_Type: GeoTIFF
    Browse_Graphic:
      Browse_Graphic_File_Name: <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology/season4_combined.tif>
      Browse_Graphic_File_Description: Image of global data set of 1985-2001 averaged SST (October to December)
      Browse_Graphic_File_Type: GeoTIFF

    Native_Data_Set_Environment: NCSA Hierarchical Data Format (HDF 4), Scientific Data Set (HDF-SDS)
    Cross_Reference:
      Citation_Information:
        Originator:
          NASA/Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive
          Center (DAAC)
        Publication_Date: Unknown
        Title: AVHRR Pathfinder products
        Geospatial_Data_Presentation_Form: Remote-sensing image
        Publication_Information:
          Publication_Place: Pasadena, CA
          Publisher: NASA/Jet Propulsion Laboratory
        Online_Linkage: <http://podaac.jpl.nasa.gov/cgi-bin/dcatalog/fam_summary.pl?sst+pfsst>

    Cross_Reference:
      Citation_Information:
        Originator:
          NASA/Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive
          Center (DAAC)
        Publication_Date: Unknown
        Title: SST Climatology products
        Geospatial_Data_Presentation_Form: Remote-sensing image
        Publication_Information:
          Publication_Place: Pasadena, CA
          Publisher: NASA/Jet Propulsion Laboratory
        Online_Linkage: <http://podaac.jpl.nasa.gov/cgi-bin/dcatalog/fam_summary.pl?sst+clim>

    Cross_Reference:
      Citation_Information:
        Originator:
          NASA/Jet Propulsion Laboratory Physical Oceanography Distributed Active Archive
          Center (DAAC)
        Publication_Date: Unknown
        Title: Multi-Channel Sea Surface Temperature products
        Geospatial_Data_Presentation_Form: Remote-sensing image
        Publication_Information:
          Publication_Place: Pasadena, CA
          Publisher: NASA/Jet Propulsion Laboratory
        Online_Linkage: <http://podaac.jpl.nasa.gov/cgi-bin/dcatalog/fam_summary.pl?sst+mcsst>

    Cross_Reference:
      Citation_Information:
        Originator: NASA Goddard Space Flight Center
        Publication_Date: Unknown
        Title: MODIS Ocean products
        Geospatial_Data_Presentation_Form: Remote-sensing image
        Publication_Information:
          Publication_Place: Greenbelt, MD
          Publisher: NASA Goddard Space Flight Center
        Online_Linkage: <http://modis.gsfc.nasa.gov/data/>


  Data_Quality_Information:
    Attribute_Accuracy:
      Attribute_Accuracy_Report:
        No rigorous tests of attribute accuracy have been performed on this data set.  For
        information on accuracy assessment of satellite SST measurements, see the 4 km
        Pathfinder Version 5.0 User Guide at
        <http://www.nodc.noaa.gov/sog/pathfinder4km/userguide.html>.

    Logical_Consistency_Report:
      The source data came from four NOAA satellites over the course of more than 15 years.
      Corrections have been made for inter-satellite differences as well as for variations
      in the data from individual satellites.  For more information on the adjustments
      performed, see the 4 km Pathfinder Version 5.0 Users Guide at
      <http://www.nodc.noaa.gov/sog/pathfinder4km/userguide.html>, and the Process Step,
      below.

      To verify data integrity, files are run against the NOAA program MD5 which indicates
      any problems in data transfer.  For more information see the original MD5
      documentation at <http://www.isi.edu/in-notes/rfc1321.txt>.
    Completeness_Report:
      The SST climatologies are global in coverage.  Most gaps in the data are in the
      extreme high latitudes and are due to the presence of persistent sea ice.

      The .HDF files represent the data as 16-bit, with pixel values that can range from 0
      to 65535.  Temperatures are represented in 0.075 degC increments.  In contrast, the
      GeoTIFF files represent the data as 8-bit, with pixel values that can range from 0 to
      255.  Temperatures are represented in 0.15 degC increments.  While the GeoTIFF files
      were developed to facilitate access and use of these data by the widest variety
      of users, the lower level of precision possible means that they are not a
      complete representation of the data in the .HDF files.

    Positional_Accuracy:
      Horizontal_Positional_Accuracy:
        Horizontal_Positional_Accuracy_Report:
          Corrections have been applied to the raw AVHRR data to adjust for drift in the
          spacecraft clock and uncertainty errors in spacecraft and sensor attitude.  For
          detailed information on correction procedures, please see Sea Surface Temperature
          Global Area Coverage (GAC) Processing Appendix A: Calibration and Navigation
          Correction Factors for a list of clock offsets for each NOAA spacecraft, at
          <http://www.rsmas.miami.edu/groups/rrsl/pathfinder/Processing/proc_app_a.html>.

    Lineage:
      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: National Oceanic and Atmospheric Administration (NOAA)
            Publication_Date: Unknown
            Title:
              5-Channel Advanced Very High Resolution Radiometer (AVHRR) Global Area
              Coverage (GAC) data
            Publication_Information:
              Publication_Place: Washington, DC
              Publisher: NOAA
            Online_Linkage: <http://www.class.noaa.gov/nsaa/products/welcome>
        Type_of_Source_Media: Online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Range_of_Dates/Times:
              Beginning_Date: 1985
              Ending_Date: 2001
          Source_Currentness_Reference: Ground condition
        Source_Citation_Abbreviation: AVHRR
        Source_Contribution: Spatial and attribute information

      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: Rosenstiel School of Marine and Atmospheric Science
            Publication_Date: 200001
            Title:
              Sea Surface Temperature Global Area Coverage (GAC) Processing, Appendix A:
              Calibration and Navigation correction factors, Tables A.1
            Publication_Information:
              Publication_Place: Miami, FL
              Publisher: Rosenstiel School of Marine and Atmospheric Science
            Online_Linkage: <http://www.rsmas.miami.edu/groups/rrsl/pathfinder/Processing/proc_app_a.html>
        Type_of_Source_Media: Online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Single_Date/Time:
              Calendar_Date: 200001
          Source_Currentness_Reference: Publication date
        Source_Citation_Abbreviation: HRPT
        Source_Contribution: Calibration information

      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: Rosenstiel School of Marine and Atmospheric Science
            Publication_Date: 200106
            Title: Matchup Database 1985–1997 (Version 19.0)
            Publication_Information:
              Publication_Place: Miami, FL
              Publisher: Rosenstiel School of Marine and Atmospheric Science
            Online_Linkage: <http://www.rsmas.miami.edu/groups/rrsl/pathfinder/Matchups/match_index.html>
        Type_of_Source_Media: Online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Single_Date/Time:
              Calendar_Date: 200106
          Source_Currentness_Reference: Publication date
        Source_Citation_Abbreviation: PFMDB
        Source_Contribution: Calibration information

      Source_Information:
        Source_Citation:
          Citation_Information:
            Originator: Land Processes Distributed Data Archive Center, U.S. Geological Survey
            Publication_Date: 2002
            Title: MODIS/Terra Land Cover Type 96-Day L3 Global 1km ISIN Grid
            Publication_Information:
              Publication_Place: Sioux Falls, SD
              Publisher: U.S. Geological Survey
            Online_Linkage: <http://edcdaac.usgs.gov/modis/mod12q1.asp>
        Type_of_Source_Media: Online
        Source_Time_Period_of_Content:
          Time_Period_Information:
            Single_Date/Time:
              Calendar_Date: 2002
          Source_Currentness_Reference: Publication date
        Source_Citation_Abbreviation: Land Mask
        Source_Contribution: Calibration information

      Process_Step:
        Process_Description:
          Sections A-D, below, describe the basic steps in the Pathfinder processing
          system; section E describes the steps required to produce the climatologies.

          Pathfinder SST Processing Steps

          A. AVHRR Global Area Coverage (GAC) data are processed to calibrate and convert
          digital counts to radiances for channels 1 through 5.  Pre-launch calibration
          data is required for processing the data from all five channels.  For channels 1
          and 2, a linear counts-to-radiance conversion is done, then sensor decay-rate
          data is used to correct for temporal changes, and finally inter-satellite
          standardization data is used to correct for inter-satellite differences, using
          NOAA-9 as the reference.  The last two steps both use data from a radiometrically
          stable target location in the Libyan desert (21°-23°N latitude; 28°-29°E
          longitude).  For channels 3, 4, and 5, a non-linear counts-to-radiance conversion
          is done using the pre-launch calibration data as well as onboard blackbody (space
          view and sensor base plate) data.

          Clock corrections are made to the data, using Earth time offset data based on
          Rosenstiel School of Marine and Atmospheric Science High-Resolution Picture
          Transmission (HRPT) data.  Attitude corrections are made using coastline
          comparison data.

          The result of these steps is  navigated, calibrated albedos/brightness
          temperatures for all five channels.  Channels 1 and 2 will not be used in the
          Pathfinder SST algorithm, and channel 3 is used only in assignment of a quality
          indicator.

          B. Channel 4 and 5 brightness temperatures are converted to SST in degrees C
          using the Pathfinder algorithm, which requires a set of monthly coefficients
          derived using the Pathfinder Buoy Matchup Database (PFMDB).  This is a set of in
          situ buoy SST observations and collocated AVHRR data.  In addition, a first-guess
          SST field is needed by the algorithm.  This first-guess field is the Reynolds
          Weekly Global Optimally Interpolated SST version 2 (OISSTv2) product.

          A quality flag for each pixel is determined by combining the results of several
          tests:  a channel 3, 4 and 5 brightness temperature test using data available
          from the calibration and conversion step, an evaluation of the viewing angle
          using a satellite zenith angle check, a reference field comparison check against
          the first-guess SST value, a stray sunlight test using information on whether
          the data in question are to left or right of nadir, an edge test which checks the
          location of the pixel within a scan line and the location of the scan line within
          the processing piece (a "piece" is a subset of an entire orbit file), a glint
          test using a glint index calculated according to the Cox and Munk formulation
          (Cox, C., and W. Munk: Measurements of the roughness of the sea surface from
          photographs of the sun’s glitter. Journal of the Optical Society of America, Vol.
          44, Issue 11, pp. 838–850, November 1954.), and application of a sea ice mask to
          identify pixels falling on areas of sea ice.  The ice mask is based on weekly
          Special Sensor Microwave/Imager (SSM/I) data and the ice information contained in
          the Reynolds OISSTv2.  (A full description of the development of the sea ice mask
          is given in the Pathfinder Version 5.0 User Guide at
          <http://www.nodc.noaa.gov/sog/pathfinder4km/userguide.html>.)

          C. Spatial binning is performed, by defining an equal-area grid into which GAC
          pixels are binned.  No external data are needed, only information on the equal-
          area binning strategy itself.  See <http://www.rsmas.miami.edu/groups/rrsl/
          pathfinder/Processing/proc_index.html#spatial_bin> for a description of spatial
          binning procedures.

          A data-day is defined following a spatial data-day definition.  See
          <http://www.nodc.noaa.gov/sog/pathfinder4km/Data-day.pdf>for a description
          of the spatial data-day definition, written by Guillermo Podesta, University of
          Miami RSMAS.

          A land mask is applied to the dataset, identifying pixels that fall on land.  In
          the 4 km Version 5.0 Pathfinder data set, a land mask based on a 1 km resolution
          MODIS dataset derived by the USGS Land Processes Distributed Active Archive
          Center is used.

          D. Temporal Binning is performed to produce daily averages.  The spatially binned
          pieces from step C are accumulated into a single ascending (daytime) or
          descending (nighttime) file for each day.  In case of overlapping satellite
          passes, only the best pixels of equivalent quality are binned.  See
          <http://www.rsmas.miami.edu/groups/rrsl/pathfinder/Processing/proc_index.html
          #temporal_binning> for a description of temporal binning procedures.  The 4 km
          Version 5.0 Pathfinder program also generates temporal averages for 5-day, 7-day,
          8-day, monthly, and yearly periods.

          A final comparison is made to an internal 3-week Pathfinder comparison field.

          Fields are reformatted from equal-area to equal-angle for distribution in HDF
          format.  While the old 9 km Pathfinder data were distributed in HDF4 Raster
          format, the new 4 km Version 5.0 Pathfinder data are distributed in HDF4-SDS
          format, with tiling (internally compressed chunks) enabled.

          E. The SST seasonal climatologies are produced.  The individual monthly files
          generated by the Version 5.0 Pathfinder Project for 1985-2001 are averaged to
          create a set of initial monthly climatologies.  For example, January of 1986,
          January of 1987,...., January of 2001 are averaged to create a climatological
          January.  Only the highest quality data (overall quality flag=7) are used.

          Following the steps described in Casey and Cornillon, 1999
          (<http://ams.allenpress.com/amsonline/?request=get-abstract&issn=1520-0442&
          volume=12&issue=6&page=1848>), most of any remaining gaps in the initial monthly
          climatology are filled by applying a 7x7 median fill; no already present data
          are modified.  Any remaining gaps are linearly filled using the previous and
          following monthly climatological values, if they are available; no already
          present data are modified.  Another 7x7 median fill is applied in case any gaps
          remain; no already present data are modified.  (Casey and Cornillon (1999)
          describe application of a final 7x7 median-filter to smooth the entire field, but
          this step is not performed for the seasonal climatologies.)

          The resulting monthly climatologies are averaged seasonally to produce a seasonal
          climatology for each season.  For example, the January, February, and March
          climatologies are averaged to create the Season 1 climatology.
        Source_Used_Citation_Abbreviation: AVHRR
        Source_Used_Citation_Abbreviation: HRPT
        Source_Used_Citation_Abbreviation: PFMDB
        Source_Used_Citation_Abbreviation: Land Mask
        Process_Date: 20040701
        Process_Contact:
          Contact_Information:
            Contact_Person_Primary:
              Contact_Person: Dr. Kenneth S. Casey
              Contact_Organization: NOAA/NESDIS National Oceanographic Data Center
            Contact_Address:
              Address_Type: Mailing address
              Address: NOAA/NESDIS National Oceanographic Data Center
              Address: SSMC3, 4th Floor, Room 4853, Route: E/OC1
              Address: 1315 East-West Highway
              City: Silver Spring
              State_or_Province: MD
              Postal_Code: 20910
              Country: USA
            Contact_Voice_Telephone: 301-713-3272 x133
            Contact_Facsimile_Telephone: 301-713-3300
            Contact_Electronic_Mail_Address: Kenneth.Casey@noaa.gov
            Hours_of_Service: 9:00 AM - 4:00 PM, Eastern time

  Spatial_Data_Organization_Information:
    Direct_Spatial_Reference_Method: Raster
    Raster_Object_Information:
      Raster_Object_Type: Grid cell
      Row_Count: 4096
      Column_Count: 8192
  Spatial_Reference_Information:
    Horizontal_Coordinate_System_Definition:
      Geographic:
        Latitude_Resolution: 0.0439453125
        Longitude_Resolution: 0.0439453125
        Geographic_Coordinate_Units: Decimal degrees
      Geodetic_Model:
        Horizontal_Datum_Name: WGS84
        Ellipsoid_Name: WGS84
        Semi-major_Axis: 6378137
        Denominator_of_Flattening_Ratio: 298.257223563

  Entity_and_Attribute_Information:
    Detailed_Description:
      Entity_Type:
        Entity_Type_Label: Sea Surface Temperature (SST) grid cell
        Entity_Type_Definition: Any of the data elements in the SST file.
        Entity_Type_Definition_Source: NOAA National Oceanographic Data Center/Satellite Oceanography Group
      Attribute:
        Attribute_Label: SST grid cell value
        Attribute_Definition:
          The grid cell values represent 1985-2001 average seasonal (Jan-Mar, Apr-Jun, Jul-
          Sep, and Oct-Dec) sea surface temperatures.  The higher the value the higher the
          SST.  Sea surface temperature in degrees C can be calculated from the pixel value
          as follows:
          >in the HDF files, SST in deg C = 0.075 x pixel value – 3.  Temperatures are
          >represented in 0.075 degree C increments, and land has a value of 1.  While
          >pixel values can range from 0 to 65535, realistic pixel values for SST will
          >always be less than 600.
          >
          >in the GeoTIFF files, SST in deg C = 0.15 x pixel value - 3. Temperatures are
          >represented in 0.15 degree C increments, and land has a value of 255.  Pixel
          >values can range from 0 to 255.
        Attribute_Definition_Source: Dr. Kenneth Casey, NODC/Satellite Oceanography Group
        Attribute_Domain_Values:
          Range_Domain:
            Range_Domain_Minimum: 0
            Range_Domain_Maximum: 500

  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Organization_Primary:
          Contact_Organization: Earth Science Information Center, U.S. Geological Survey
        Contact_Address:
          Address_Type: Mailing address
          Address: 507 National Center
          City: Reston
          State_or_Province: VA
          Postal_Code: 20192
        Contact_Voice_Telephone: 1-888-ASK-USGS (1-888-275-8747)
        Contact_Voice_Telephone: 703-648-5920
        Contact_Instructions:
          In addition to the address above there are other ESIC offices
          throughout the country.  A full list of these offices is at
          <http://ask.usgs.gov/esic_index.html>.
    Distribution_Liability:
      Although these data have been processed successfully on a computer system
      at the U.S. Geological Survey, no warranty expressed or implied is made by
      the U.S. Geological Survey regarding the utility of the data on any other
      system, nor shall the act of distribution constitute any such warranty.
      No responsibility is assumed by the U.S. Geological Survey in the use of
      these data.
    Standard_Order_Process:
      Digital_Form:
        Digital_Transfer_Information:
          Format_Name: GeoTIFF
        Digital_Transfer_Option:
          Online_Option:
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <http://nationalatlas.gov/atlasftp.html?openChapters=chpclim#chpclim>
      Fees: There is no charge for the data set.

  Distribution_Information:
    Distributor:
      Contact_Information:
        Contact_Organization_Primary:
          Contact_Organization: NOAA National Oceanographic Data Center
        Contact_Address:
          Address_Type: Mailing and physical address
          Address: SSMC3, 4th Floor, E/OC1
          Address: 1315 East-West Highway
          City: Silver Spring
          State_or_Province: MD
          Postal_Code: 20910
          Country: USA
        Contact_Voice_Telephone: 301-713-3277
        Contact_Voice_Telephone: 301-713-3280
        Contact_Facsimile_Telephone: 301-713-3301
        Contact_Electronic_Mail_Address: nodc.services@noaa.gov
        Hours_of_Service: 8:00 - 6:00 PM, Eastern time
        Contact_Instructions: Phone/FAX/E-mail/letter during business hours
    Resource_Description: NODC Accession #0001658
    Distribution_Liability:
      NOAA makes no warranty regarding these data, expressed or implied, nor does the
      fact of distribution constitute such a warranty.  NOAA and NODC cannot assume
      liability for any damages caused by any errors or omissions in these data, nor as a
      result of the failure of these data to function on a particular system.
    Standard_Order_Process:
      Digital_Form:
        Digital_Transfer_Information:
          Format_Name: HDF
          Format_Version_Number: 4
          Format_Specification: NCSA Hierarchical Data Format (HDF 4), Scientific Data Set (HDF-SDS)
          Format_Information_Content:
            Four .HDF files comprising seasonal climatologies 1985-2001 (seasons as defined
            by periods Jan-Mar, Apr-Jun, Jul-Sept, Oct-Dec).  Four 8-bit GeoTIFF files of
            the same climatologies are bundled with the .HDF files.
          File_Decompression_Technique:
            HDF-SDS files employ internal "deflate" compression which is identical to
            "gzip" compression.
          Transfer_Size: 30000000
        Digital_Transfer_Option:
          Online_Option:
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <http://www.nodc.noaa.gov/search/prod/>
            Access_Instructions:
              Data may be directly downloaded.  NODC can be contacted directly for custom
              orders.  (When requesting data from the NODC, the desired data set may
              be referred to as NODC Accession #0001658).
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology>
            Online_Computer_and_Operating_System: PC, MAC, or other server such as Linux, Unix; FTP capability
      Digital_Form:
        Digital_Transfer_Information:
          Format_Name: TIFF
          Format_Version_Number: 1
          Format_Specification: GeoTIFF
          Format_Information_Content:
            Four 8-bit GeoTIFF representations of seasonal climatologies 1985-2001 (seasons
            as defined by periods Jan-Mar, Apr-Jun, Jul-Sept, Oct-Dec).  Four 16-bit .HDFD
            files of the same climatologies are bundled with the GeoTIFF files.  Although
            the data are represented using 16-bit in the .HDF files, 8-bit GeoTIFF files
            were developed to facilitate access and use of these data by the widest variety
            of users; as such the GeoTIFF representations of the .HDF files are not a
            complete representation of the data in the .HDF files.
          File_Decompression_Technique: GeoTIFF files employ internal "packbits" compression.
          Transfer_Size: 36000000
        Digital_Transfer_Option:
          Online_Option:
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <http://www.nodc.noaa.gov/search/prod/>
            Access_Instructions:
              Data may be directly downloaded.  NODC can be contacted directly for custom
              orders.  (When requesting data from the NODC, the desired data set may
              be referred to as NODC Accession #0001658).
            Computer_Contact_Information:
              Network_Address:
                Network_Resource_Name: <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology>
            Online_Computer_and_Operating_System: PC, MAC, or other server such as Linux, Unix; FTP capability
      Fees: None
      Ordering_Instructions:
        Data may be directly downloaded through the NODC website at:
        <http://www.nodc.noaa.gov/search/prod/>.  NODC can be contacted directly for custom
        orders.  (When requesting data from the NODC, the desired data set may be referred
        to as NODC Accession #0001658).  In addition, these data and accompanying browse
        graphics may be directly downloaded from the NODC FTP server at:
        <ftp://ftp.nodc.noaa.gov/pub/pathfinder/seasonal_climatology>.
      Turnaround: Within 24 hours if downloaded via the Internet
    Custom_Order_Process: Contact the NODC User Services Group via phone/FAX/E-mail: nodc.services@noaa.gov
    Technical_Prerequisites:
      PC, Mac, or other server, standard Internet browser, ability to work with .HDF and/or
      GeoTIFF files strongly recommended.

  Metadata_Reference_Information:
    Metadata_Date: 20060607
    Metadata_Contact:
      Contact_Information:
        Contact_Person_Primary:
          Contact_Person: Sheri Phillips or Amanda Lowe
          Contact_Organization: NOAA/NODC
        Contact_Address:
          Address_Type: Mailing address
          Address: 1315 East-West Highway, E/OC1, SSMC3, 4th Floor
          City: Silver Spring
          State_or_Province: MD
          Postal_Code: 20910
          Country: USA
        Contact_Voice_Telephone: 301-713-3280 x127
        Contact_Facsimile_Telephone: 301-713-3302
        Contact_Electronic_Mail_Address: sheri.phillips@noaa.gov
        Hours_of_Service: 9:30 AM - 6 PM  Monday-Thursday
        Contact_Instructions: E-mail, phone, FAX, mail
    Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
    Metadata_Standard_Version: FGDC-STD-001-1998
    Metadata_Time_Convention: Local time
    Metadata_Access_Constraints: None
    Metadata_Use_Constraints: None
    Metadata_Security_Information:
      Metadata_Security_Classification_System: None
      Metadata_Security_Classification: Unclassified
      Metadata_Security_Handling_Description: None