{91B00062-D0B1-4215-951F-8B476EF46AE9}2003111623164000FALSE20040908104546002005082613134000Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.3.0.800 This vector based data set was derived from an ArcGIS grid (of 1.1 km cells) and represents spring leads along the coast of Northern Alaska (West of Barrow) and Northwest Canada (East of the Mackenzie Delta) for the study area which ranges from approximately 130 to 164 degrees West and 68.5 to 74 degrees North. This data was compiled by the University of Alaska Fairbanks to meet contract requirements for the US Mineral Management Service: Mapping and Characterization of Recurring Spring Leads and Landfast ice in the Beaufort and Chukchi Seas (AK-03-06) enFor the purposes of the MMS study, the file names associated with Band 1 data (visual) are prefixed with a "v" and Band 4 files (thermal) prefixed with a "t". The day of the year, hour and minutes are incorporated in the file names. For descriptive purposes the following abbreviations are used as placeholders for real values to illustrate the naming convention: d = day of year Y = Year T = time in GMT A Band 1 shapefile follows this convention: v d d d _T T T Tshape A Band 4 shapefile follows this convention: t d d d _T T T Tshape Examples of these file names are v015_1012shape and t015_1012shape University of Alaska Fairbanks 20051231 vector digital data http://mms.gina.alaska.edu t93364 197201 unknown ground condition In work As needed -164.176389-129.97865473.94719968.481396-332368.468723814227.4999732181116.5002642652000.000265 Aquatic Sciences and Fisheries Thesaurus spring leads sea icelead Dictionary of Alaska Place Names Arctic Ocean Chukchi SeaBeaufort SeaNorth SlopeAlaskaCanada None.Any hardcopies or published information utilizing these data sets shall clearly indicate their source. If the user has modified the data in any way they are obligated to describe the types of modifications that they have performed. User specifically agrees not to misrepresent these datasets, nor to imply that any changes that they made were approved by the University of Alaska.Vector Data set Dr. Hajo Eicken Geophysical Institute Unversity of Alaska Fairbanks mailing and physical address

903 Koyukuk Dr., P.O. Box 757320

Fairbanks Alaska 99775-7320 USA 907-474-7280 907-474-7290 hajo.eicken@gi.alaska.edu The funding for this effort was provided by the US Mineral Management Service for Mapping and Characterization of Recurring Spring Leads and Landfast ice in the Beaufort and Chukchi Seas (AK-03-06, MMS-71707) *.jpgLow resolution browse graphic of shapefileJPEGMicrosoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.3.0.800t93364-332368.468723814227.4999732652000.0002652181116.5002641-164.176389-129.97865473.94719968.4813961 20040915 Nuna Technologies Allison Graves Gaylord Owner / GIS Specialist mailing address

P.O. Box 1483

Homer AK 99723-1483 USA 907.235.3476 nunatech@usa.net FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time enNone.If the user has modified the data in any way they are obligated to describe the types of modifications they have performed in the supporting metadata file. User specifically agrees not to imply that changes they made were approved by the University of Alaska.None.UnclassifiedNone.http://www.esri.com/metadata/esriprof80.htmlESRI Metadata Profile ISO 19115 Geographic Information - MetadataDIS_ESRI1.0dataset UAF Geographic Information Network of Alaska (GINA) Dr. Virgil (Buck) Sharpton mailing and physical address

903 Koyukuk Drive

Fairbanks Alaska 99775-7320 USA 907.474.6663 buck.sharpton@gina.alaska.edu President's Professor of Remote Sensing8:00 a.m. - 5:00 p.m. AST Downloadable Data The University of Alaska makes no express or implied warranties (including warranties of merchantability and fitness) with respect to the character, function, or capabilities of the electronic services or products or their appropriateness for any users purposes. In no event will the University of Alaska be liable for any incidental, indirect, special, consequential or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products, any failure thereof or otherwise, and in no event will the State of Alaska's liability to the requestor or anyone else exceed the fee paid for the electronic service or product. ESRI ArcGIS format 200301101 ESRI Grid / ESRI Shapefile 0.826 0.826 http://mms.gina.alaska.edu web browser and/or FTP None unknown unknown 002file://\\NUNALAPTOP\N$\MMS\Web\mms\private\data\lead\1993\Dec\foo\MetadataVector\t93364.shpLocal Area Network0.826Shapefile Vector PolygonSimpleFALSE1564FALSEFALSEG-polygon1564 coordinate pair 0.002048 0.002048 meters Albers Conical Equal Area55.00000065.000000-154.00000050.0000000.0000000.000000 North American Datum of 1983 Geodetic Reference System 80 6378137.000000 298.257222 GCS_North_American_1983NAD_1983_Albers NAD_1983_Albers210601626111564 Spring Leads Band 1 ESRI Feature Class1564 FIDFIDOID43Feature ID of shapefileESRIFIDFeature Identifier of ShapefileESRI00ShapeShapeGeometry0Feature ClassESRIShapeFeature Class = PolygonESRI00AreaAREANumber9Area of polygonESRI AreaArea of PolygonAutomatically calculated by ArcGIS3PERIMETERPERIMETERNumber9PerimeterPerimeter of polygonAutomatically calculated by ArcGISperimeter of polygonESRI3_#######T93364_Number9Internal Feature Number ESRI_######Internal Feature Number Residual Attribute Generated by conversion to ArcGIS Coverage######_IDT93364_IDNumber9Internal IdentifierESRI######_IDInternal IdentifierResidual Attribute Generated by conversion to ArcGIS CoverageGRID_CODEGRID_CODENumber9Value = 255iceDerived from binary classification of AVHRR source imagery.Value = 0leadsBinarized classification of AVHRR source imagery.Grid code for cell valueESRI 20050826 Map projection and datum were confirmed and checked to conform with base data sets and imagery. Complete. The International Observatory of the North (ION) uses satellite navigation and attitude parameters for scene navigation (with additional ground control) to produce adequate results (with errors <3 km) for geolocated AVHRR imagery. ION data sets were used as a base map to derive the lead segmentation. 3000 meters Visual inspection. Distance measurement tools. AVHRR data was geolocated, calibrated and reprojected in GeoTIFF format using TeraScan software. A coast mask is applied in ENVI. The fraction of leads within each pixel is then determined based on the brightness temperatures or reflectances of open water and the surrounding thick ice, as described by Lindsay and Rothrock (Arctic sea ice leads from advanced very high resolution radiometer images. Journal of Geophysical Research, 100(C3), 4533-4544, 1995). Here, we have corrected for regional differences in surface temperature and reflectance as well as thin cloud cover by determining the fraction of leads within a moving 50 by 50 pixel (55 x 55 km) square window, with the fraction of thick ice based on the upper and lower quartile reflectance and brightness temperature, respectively. For a few cases of more expansive stretches of open water, manual adjustments of open water extent have been made. The resulting image indicating the fraction of open water is then binarized about a threshold corresponding to an open water fraction of 25% in each pixel, with pixels containing less open water designated as ice and those at or above 25% designated as leads. This information is then brought into NIH Image for derivation of lead location, shape and size statistics, open water fractions and other information for the different study subregions. An IDL script was used to export the binarized files into GeoTiff format. The batch utility within ArcToolbox was used to convert GeoTiffs to ArcGIS Grid format. A batch file was used in ArcCatalog to define the map projection and datum. Each Grid file was then converted to an ArcGIS Coverage file and then Shapefile using batch utilities within ArcToolbox. Low resolution browse images (*.jpg format) were generated for display on the project web site. Final processing included a batch import of the appropriate FGDC compliant metadata template. Final data sets were bundled with Winzip for posting to the web to ensure clean data transfer of the components of the shapefile, plus associated metadata record and browse image. 2004 Dr. Hajo Eicken University of Alaska Fairbanks, Geophysical Institute Associate Professor mailing and physical address

903 Koyukuk Dr., P.O. Box 757320

Fairbanks AK 99775-7320 USA 907-474-7196 907-474-7290 Hajo.Eicken@gi.alaska.edu business hours