Sea-Ice Lead Statistics (Size, Morphology) for the Chukchi and Beaufort Seas, offshore of Northern Alaska, USA and Northwest Canada from 1993-2004.

Metadata:
Identification_Information:
Citation:
Citation_Information:
Originator: University of Alaska Fairbanks
Publication_Date: 20051231
Title:
Sea-Ice Lead Statistics (Size, Morphology) for the Chukchi and Beaufort Seas, offshore of Northern Alaska, USA and Northwest Canada from 1993-2004.
Geospatial_Data_Presentation_Form: tabular digital data
Online_Linkage: http://mms.gina.alaska.edu
Description:
Abstract:
This Excel Workbook summarizes the statistics associated with the percent of open water for Spring sea ice leads for 12 subregions covering the offshore area from Northern Alaska (West of Wainwright) across 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.
Purpose:
These data were 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)
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 19931201
Beginning_Time: unknown
Ending_Date: 20040610
Ending_Time: unknown
Currentness_Reference:
ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -164.176389
East_Bounding_Coordinate: -129.978654
North_Bounding_Coordinate: 73.947199
South_Bounding_Coordinate: 68.481395
Keywords:
Theme:
Theme_Keyword_Thesaurus: Aquatic Sciences and Fisheries Thesaurus
Theme_Keyword: spring leads
Theme_Keyword: sea ice
Theme_Keyword: lead
Place:
Place_Keyword_Thesaurus: Dictionary of Alaska Place Names
Place_Keyword: Arctic Ocean
Place_Keyword: Chukchi Sea
Place_Keyword: Beaufort Sea
Place_Keyword: North Slope
Place_Keyword: Alaska
Place_Keyword: Canada
Access_Constraints: None.
Use_Constraints:
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.
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Dr. Hajo Eicken
Contact_Organization: Geophysical Institute
Contact_Position: Principal Investigator
Contact_Address:
Address_Type: mailing and physical address
Address:
903 Koyukuk Dr., P.O. Box 757320
City: Fairbanks
State_or_Province: Alaska
Postal_Code: 99775-7320
Country: USA
Contact_Voice_Telephone: 907-474-7280
Contact_Facsimile_Telephone: 907-474-7290
Contact_Electronic_Mail_Address: hajo.eicken@gi.alaska.edu
Browse_Graphic:
Browse_Graphic_File_Name: Means.xls
Browse_Graphic_File_Description:
Microsoft Excel Workbook
Browse_Graphic_File_Type: xls
Data_Set_Credit:
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)
Native_Data_Set_Environment:
Microsoft Windows 2000 Version 5.0 (Build 2195) Service Pack 4; ESRI ArcCatalog 8.3.0.800
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Data_Quality_Information:
Logical_Consistency_Report:
Lead statistics were based on the results of binarized segmentation processing of AVHRR data.
Completeness_Report:
Complete.
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
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.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 3000 meters
Horizontal_Positional_Accuracy_Explanation:
Visual inspection.  Distance measurement tools.
Lineage:
Process_Step:
Process_Description:
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. 

Overall lead statistics were then compiled in a Microsoft Excel Workbook with associated graphs.
Process_Date: 200504
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Dr. Hajo Eicken
Contact_Organization: University of Alaska Fairbanks, Geophysical Institute
Contact_Position: Principal Investigator
Contact_Address:
Address_Type: mailing and physical address
Address:
903 Koyukuk Dr., P.O. Box 757320
City: Fairbanks
State_or_Province: AK
Postal_Code: 99775-7320
Country: USA
Contact_Voice_Telephone: 907-474-7280
Contact_Facsimile_Telephone: 907-474-7290
Contact_Electronic_Mail_Address: Hajo.Eicken@gi.alaska.edu
Hours_of_Service: business hours
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Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Raster_Object_Information:
Raster_Object_Type: Pixel
Row_Count: 626
Column_Count: 1060
Vertical_Count: 1
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Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: leadfract_all
Entity_Type_Definition:
Percent open water / lead statistics for all ice seasons 1993-2004
Entity_Type_Definition_Source:
UAF
Attribute:
Attribute_Label: OID
Attribute_Definition:
Internal Object Identifier
Attribute_Definition_Source:
ESRI ArcCatalog
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: OID
Enumerated_Domain_Value_Definition:
Internal Object Identifier
Enumerated_Domain_Value_Definition_Source:
ESRI ArcCatalog
Attribute:
Attribute_Label: FILE_NAME
Attribute_Definition:
File Name
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: File name
Enumerated_Domain_Value_Definition:
AVHRR File Name (t = thermal, v = visual, Year (YY format), Day of Year
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: DAY_OF_YEAR
Attribute_Definition:
Day of Year
Attribute_Definition_Source:
Julian Calender
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Day of Year
Enumerated_Domain_Value_Definition:
Day of Year
Enumerated_Domain_Value_Definition_Source:
Julian Calender
Attribute:
Attribute_Label: DAYS_SINCE_Sept_1
Attribute_Definition:
DAYS_SINCE_Sept_1
Attribute_Definition_Source:
Julian Calender
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: DAYS_SINCE_Sept_1
Enumerated_Domain_Value_Definition:
DAYS_SINCE_Sept_1
Enumerated_Domain_Value_Definition_Source:
Julian Calender
Attribute:
Attribute_Label: 1
Attribute_Definition:
AVHRR Subregion 1
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 1
Enumerated_Domain_Value_Definition:
AVHRR Subregion 1
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 2
Attribute_Definition:
AVHRR Subregion 2
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 2
Enumerated_Domain_Value_Definition:
AVHRR Subregion 2
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 3
Attribute_Definition:
AVHRR Subregion 3
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 3
Enumerated_Domain_Value_Definition:
AVHRR Subregion 3
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 4
Attribute_Definition:
AVHRR Subregion 4
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 4
Enumerated_Domain_Value_Definition:
AVHRR Subregion 4
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 5
Attribute_Definition:
AVHRR Subregion 5
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 5
Enumerated_Domain_Value_Definition:
AVHRR Subregion 5
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 6
Attribute_Definition:
AVHRR Subregion 6
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 6
Enumerated_Domain_Value_Definition:
AVHRR Subregion 6
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 7
Attribute_Definition:
AVHRR Subregion 7
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 7
Enumerated_Domain_Value_Definition:
AVHRR Subregion 7
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 8
Attribute_Definition:
AVHRR Subregion 8
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 8
Enumerated_Domain_Value_Definition:
AVHRR Subregion 8
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 9
Attribute_Definition:
AVHRR Subregion 9
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 9
Enumerated_Domain_Value_Definition:
AVHRR Subregion 9
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 10
Attribute_Definition:
AVHRR Subregion 10
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 10
Enumerated_Domain_Value_Definition:
AVHRR Subregion 10
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 11
Attribute_Definition:
AVHRR Subregion 11
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 1
Enumerated_Domain_Value_Definition:
AVHRR Subregion 11
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: 12
Attribute_Definition:
AVHRR Subregion 12
Attribute_Definition_Source:
UAF
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: 12
Enumerated_Domain_Value_Definition:
AVHRR Subregion 12
Enumerated_Domain_Value_Definition_Source:
UAF
Attribute:
Attribute_Label: MEAN
Attribute_Definition:
Mean
Attribute_Definition_Source:
NIH Image/Scion Image software
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Mean
Enumerated_Domain_Value_Definition:
Mean
Enumerated_Domain_Value_Definition_Source:
NIH Image/Scion Image software
Attribute:
Attribute_Label: STD_DEV
Attribute_Definition:
Standard Deviation
Attribute_Definition_Source:
NIH Image/Scion Image software
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Std_Dev
Enumerated_Domain_Value_Definition:
Standard Deviation
Enumerated_Domain_Value_Definition_Source:
NIH Image/Scion Image software
Attribute:
Attribute_Label: NUMBER_OF_DATA_POINTS
Attribute_Definition:
NUMBER_OF_DATA_POINTS
Attribute_Definition_Source:
NIH Image/Scion Image software
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: NUMBER_OF_DATA_POINTS
Enumerated_Domain_Value_Definition:
Number of data points based on availability / cloud cover for each subregion
Enumerated_Domain_Value_Definition_Source:
NIH Image/Scion Image software
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: UAF Geographic Information Network of Alaska (GINA)
Contact_Person: Dr. Virgil (Buck) Sharpton
Contact_Position: President's Professor of Remote Sensing
Contact_Address:
Address_Type: mailing and physical address
Address:
903 Koyukuk Drive
City: Fairbanks
State_or_Province: Alaska
Postal_Code: 99775-7320
Country: USA
Contact_Voice_Telephone: 907.474.6663
Contact_Electronic_Mail_Address: buck.sharpton@gina.alaska.edu
Hours_of_Service: 8:00 a.m. - 5:00 p.m. AST
Resource_Description: Downloadable Data
Distribution_Liability:
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.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: Microsoft Excel Workbook
Format_Version_Date: 20040908
Format_Specification:
Microsoft Office XP Excel Workbook
Transfer_Size: 0.001
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: http://mms.gina.alaska.edu
Access_Instructions:
web browser and/or FTP
Fees: None
Available_Time_Period:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: unknown
Ending_Date: unknown
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Metadata_Reference_Information:
Metadata_Date: 20050429
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: Nuna Technologies
Contact_Person: Allison Graves Gaylord
Contact_Position: Owner / GIS Specialist
Contact_Address:
Address_Type: mailing address
Address:
P.O. Box 1483
City: Homer
State_or_Province: AK
Postal_Code: 99723-1483
Country: USA
Contact_Voice_Telephone: 907.235.3476
Contact_Electronic_Mail_Address: nunatech@usa.net
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:
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.
Metadata_Security_Information:
Metadata_Security_Classification_System: None.
Metadata_Security_Classification: Unclassified
Metadata_Security_Handling_Description:
None.
Metadata_Extensions:
Online_Linkage: http://www.esri.com/metadata/esriprof80.html
Profile_Name: ESRI Metadata Profile
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