Entry_ID: G02173
Entry_Title: Recurring Spring Leads and Landfast Ice in the Beaufort and Chukchi Seas, 1993-2004
Group: Data_Set_Citation
   Dataset_Creator: Eicken, H., L. Shapiro, A. G. Gaylord, A. Mahoney, and P. W. Cotter. 
   Dataset_Title: Recurring Spring Leads and Landfast Ice in the Beaufort and Chukchi Seas, 1993-2004
   Dataset_Release_Date: 2009-06-17
   Dataset_Release_Place: Boulder, Colorado USA
   Dataset_Publisher: NSIDC: National Snow and Ice Data Center
   Online_Resource: http://nsidc.org/data/g02173.html
   Dataset DOI: http://dx.doi.org/10.7265/N5SB43P0
End_Group
Group: Personnel
   Role: Investigator
   First_Name: Hajo
   Last_Name: Eicken
   Group: Contact_Address
      Address: University of Alaska Fairbanks
      Address: Geophysical Institute
      Address: P.O. Box 757320
      City: Fairbanks
      Province_or_State: AK
      Postal_Code: 99775-7320
      Country: USA
   End_Group
End_Group
Group: Personnel
   Role: Investigator
   First_Name: Lewis
   Last_Name: Shapiro
   Group: Contact_Address
      Address: University of Alaska Fairbanks
      Address: Geophysical Institute
      City: Fairbanks
      Province_or_State: AK
      Postal_Code: 99775-7320
      Country: USA
   End_Group
End_Group
Group: Personnel
   Role: Investigator
   First_Name: Allison
   Last_Name: Graves Gaylord
   Email: NunaTech@usa.net
   Phone: 1 907 852-4881 
   Fax: 1 907  852-4882 
   Group: Contact_Address
      Address: Nuna Technologies
      Address: P.O. Box 1483
      City: Homer
      Province_or_State: AK
      Postal_Code: 3
   End_Group
End_Group
Group: Personnel
   Role: Technical Contact
   First_Name: NSIDC
   Last_Name: User Services
   Email: nsidc@nsidc.org
   Phone: 1 303 492-6199 x
   Fax: 1 303  492-2468 x
   Group: Contact_Address
      Address: National Snow and Ice Data Center
      Address: CIRES, 449 UCB
      Address: University of Colorado
      City: Boulder
      Province_or_State: CO
      Postal_Code: 80309-0449
      Country: USA
   End_Group
End_Group
Group: Personnel
   Role: Investigator
   First_Name: P
   Middle_Name: W
   Last_Name: Cotter
   Group: Contact_Address
      Address: Geophysical Institute, University of Alaska, Fairbanks
   End_Group
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Ice Edges
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Ice Edges
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Leads
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Cryosphere
   Term: Sea Ice
   Variable_Level_1: Leads
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Ice Edges
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Ice Edges
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Ice Extent
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Leads
End_Group
Group: Parameters
   Category: EARTH SCIENCE
   Topic: Oceans
   Term: Sea Ice
   Variable_Level_1: Leads
End_Group
ISO_Topic_Category: Climatology/Meteorology/Atmosphere
Keyword: AVHRR
Keyword: Beaufort Sea
Keyword: Chukchi Sea
Keyword: Infrared
Keyword: landfast ice
Keyword: Leads
Keyword: NOAA
Keyword: RADARSAT-1
Keyword: Radarsat imagery
Keyword: SAR imagery
Keyword: Sea Ice Extent
Keyword: Visible Imagery
Sensor_Name: AVHRR > Advanced Very High Resolution Radiometer
Sensor_Name: SAR > Synthetic Aperture Radar
Source_Name: NOAA-12 > National Oceanic & Atmospheric Administration-12
Source_Name: NOAA-14 > National Oceanic & Atmospheric Administration-14
Source_Name: NOAA-15 > National Oceanic & Atmospheric Administration-15
Source_Name: NOAA-16 > National Oceanic & Atmospheric Administration-16
Source_Name: NOAA-17 > National Oceanic & Atmospheric Administration-17
Source_Name: RADARSAT-1
Group: Temporal_Coverage
   Start_Date: 1993-12-09
   Stop_Date: 2004-07-29
End_Group
Data_Set_Progress: complete
Group: Spatial_Coverage
   Southernmost_Latitude: 68.48204
   Northernmost_Latitude: 73.95769
   Westernmost_Longitude: -164.08084
   Easternmost_Longitude: -129.87714
End_Group
Group: Location
   Location_Category: OCEAN
   Location_Type: ARCTIC OCEAN
   Location_Subregion1: BEAUFORT SEA
End_Group
Group: Location
   Location_Category: OCEAN
   Location_Type: ARCTIC OCEAN
   Location_Subregion1: CHUKCHI SEA
End_Group
Group: Data_Resolution
   Latitude_Resolution: 1.1 km
   Longitude_Resolution: 1.1 km
End_Group
Group: Data_Resolution
   Latitude_Resolution: 100 m
   Longitude_Resolution: 100 m
End_Group
Group: Quality

   Note: NSIDC did not perform a quality assessment of the data. 

   Landfast Ice Extent:

   The manual process for identifying landfast ice extent has subjectivity. 
   However, this subjectivity was reduced by using a gradient difference. Refer 
   to the landfast ice extent Data Processing section of this document for more 
   information on the gradient difference. 

   The following is a list of the quality checks performed on the landfast ice 
   (Mahoney et al. 2005): * Data were checked for adequate coverage over the 
   study area (subregions 2-11).  * Images with a large geolocation error were 
   identified and either corrected or disregarded.

   * The geolocation accuracy could create collocation errors of up to 10 pixels 
   or 1 km between parts of two mosaics.

   Leads:

   The following checks were performed on the AVHRR data:

   * Manually examined all scenes and excluded images or image sections with any 
   trace of cloud cover or ambiguous lead/cloud features to keep the potential 
   source of error due to clouds and fog to a minimum.

   * Classified lead/ice images were compared to ship-based observations of lead 
   fractions in May and June of 2004 and found to be in reasonable agreement with 
   a deviation of two and one percentage-point, respectively.

End_Group
Data_Set_Language: English
Originating_Center: NOAA
Group: Data_Center
   Data_Center_Name: NSIDC > National Snow and Ice Data Center
   Data_Center_URL: http://nsidc.org
   Group: Personnel
      Role: Data Center Contact
      First_Name: NSIDC
      Last_Name: User Services
      Email: nsidc@nsidc.org
      Phone: 1 303 492-6199 
      Fax: 1 303  492-2468 
      Group: Contact_Address
         Address: National Snow and Ice Data Center
         Address: CIRES, 449 UCB
         Address: University of Colorado
         City: Boulder
         Province_or_State: CO
         Postal_Code: 80309-0449
         Country: USA
      End_Group
   End_Group
End_Group
Group: Data_Center
   Data_Center_Name: NOAA > National Oceanic and Atmospheric Administration
   Data_Center_URL: http://nsidc.org/noaa/
   Group: Personnel
      Role: Data Center Contact
      First_Name: NOAA
      Last_Name: User Services
      Email: nsidc@nsidc.org
      Phone: 1 303 492-6199 x
      Fax: 1 303  492-2468 x
      Group: Contact_Address
         Address: National Snow and Ice Data Center
         Address: CIRES, 449 UCB
         Address: University of Colorado
         City: Boulder
         Province_or_State: CO
         Postal_Code: 80309-0449
         Country: USA
      End_Group
   End_Group
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: .1 - 30 MB
   Distribution_Format: ESRI Grid
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: .1 - 30 MB
   Distribution_Format: ESRI Interchange
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: .1 - 30 MB
   Distribution_Format: Microsoft Excel
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: 15 - 22 KB
   Distribution_Format: XML
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: 7 - 86 MB
   Distribution_Format: Microsoft Access
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: .1 - 30 MB
   Distribution_Format: ESRI Shapefiles (.shp, .shx, .dbf, and .prj)
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: .1 - 30 MB
   Distribution_Format: Joint Photographic Expert Group (JPEG) (.jpg)
End_Group
Group: Distribution
   Distribution_Media: FTP
   Distribution_Size: .1 - 30 MB
   Distribution_Format: Geographic Tagged Image File Format (GeoTIFF) (.geotiff)
End_Group
Group: Reference

   Eicken, H., L. Shapiro, A. G. Gaylord, A. Mahoney, and P. Cotter. 2006. 
   Mapping and Characterization of Recurring Spring Leads and Landfast Ice in the 
   Beaufort and Chukchi Seas. Final Report, Minerals Management Service OCS Study 
   MMS 2005-068.

   Eicken, H., R. Gradinger, A. Graves, A. Mahoney, I. Rigor, and H. Melling. 
   2005. Sediment Transport by Sea Ice in the Chukchi and Beaufort Seas: 
   Increasing Importance Due to Changing Ice Conditions? Deep-Sea Research II 52: 
   3281-3302.

   Fett, R. W., R. E. Englebretson, and S. D. Burk. 1997. Technologies for 
   Analyzing Lead Condition in Visible, Infrared and Microwave Satellite Imagery. 
   Journal of Geophysical Research 102: 13657-13671.

   Key, J. R., R. Stone, J. A. Maslanik, and E. Ellefsen. 1993. The Detectability 
   of Sea-Ice Leads in Satellite Data as a Function of Atmospheric Conditions and 
   Measurement Scale, Annals of Glaciology 17: 227-232.

   Kwok, R. and G. F. Cunningham. 1994. Use of Time Series SAR Data to Resolve 
   Ice Type Ambiguities in Newly Opened Leads. IGARSS'94: International 
   Geoscience and Remote Sensing Symposium. Surface and Atmospheric Remote 
   Sensing: Technologies, Data Analysis, and Interpretation: 1024-1026.

   Lindsay, R. W. and D. A. Rothrock. 1995. Arctic Sea Ice Leads from Advanced 
   Very High Resolution Radiometer Images. Journal of Geophysical Research 100: 
   4533-4544.

   Mahoney, A. 2006. 'Alaska Landfast Sea Ice Dynamics.' Ph.D. Thesis, University 
   of Alaska Fairbanks, Fairbanks, AK, August 2006.

   Mahoney, A., H. Eicken, L. Shapiro, and A. Graves. 2005. Defining and Locating 
   the Seaward Landfast Ice Edge in Northern Alaska. In: 18th International 
   Conference on Port and Ocean Engineering under Arctic Conditions, J.P. Dempsey 
   (Editor). POAC '05 Proceedings Volume 3, Potsdam, NY, June 26-30, 2005.

   Mahoney, A., H. Eicken, A. G. Gaylord, and L. Shapiro. 2007. Alaska Landfast 
   Sea Ice: Links with Bathymetry and Atmospheric Circulation. Journal of 
   Geophysical Research 112, C02001.

   Stroeve, J., M. Serreze, S. Drobot, S. Gearheard, M. Holland, J. Maslanik, W. 
   Meier, and T. Scambos. 2008. Arctic Sea Ice Extent Plummets in 2007. EOS, 
   89(2), 8 January.

End_Group
Group: Summary

   In the Beaufort and Chukchi Seas, the most significant sea ice anomalies have 
   occurred in the summer ice extent (Eicken et al. 2006). In addition, there has 
   been a considerable decline in the multiyear ice pack in this region (Eicken 
   et al. 2006). To help understand these anomalies, this data set contains 
   information on recurring spring leads and landfast ice extent in this area. 
   This data set maps and documents the spatial and temporal distribution of 
   recurring leads and landfast ice off the coast of northern Alaska in the 
   Chukchi and Beaufort Seas (Eicken et al. 2006). The leads data span from 1993 
   through 2004 and are based on visible and infrared Advanced Very High 
   Resolution Radiometer (AVHRR) data onboard the NOAA 12, 14, 15, 16, and 17 
   satellites. The landfast ice extent data extend from 1996 through 2004 and are 
   based on RADARSAT-1 Synthetic Aperture Radar (SAR) imagery. The data are 
   available in a number of formats including ArcGIS geodatabases (.mdb), 
   shapefiles (.shp), ArcGIS grids (.adf), ArcGIS grids in ArcInfo interchange 
   format (.e00), and GeoTIFFs (.tif). Statistics are also provided in Microsoft 
   Excel spreadsheets (.xls) and metadata in several formats including XML 
   (.xml), SGML (.sgml), HTML (.html), and ASCII text (.txt). Quick-view browse 
   images in JPEG (.jpg) format are provided for the shapefiles, grids, and 
   GeoTIFFs. Data are available via FTP.

End_Group
Group: Related_URL
   Group: URL_Content_Type
      Type: VIEW PROJECT HOME PAGE
   End_Group
   URL: http://nsidc.org/noaa/index.html
   Description: NOAA at NSIDC Web Site
End_Group
Metadata_Name: CEOS IDN DIF
Metadata_Version: 9.7
DIF_Creation_Date: 2009-06-17
Last_DIF_Revision_Date: 2013-03-12
DIF_Revision_History:  Added DOI to metadata record