Arctic Coastal Dynamics (ACD) Elson Lagoon Key Site Section A, August 2003-2009 Shoreline Change Polygon, Barrow, Alaska, USA.

Metadata:


Identification_Information:
Citation:
Citation_Information:
Originator: University of Texas at El Paso, Systems Ecology Lab
Publication_Date: 20091101
Title:
Arctic Coastal Dynamics (ACD) Elson Lagoon Key Site Section A, August 2003-2009 Shoreline Change Polygon, Barrow, Alaska, USA.
Geospatial_Data_Presentation_Form: vector digital data
Other_Citation_Details:
Aguirre, A, J. Brown, A. Gaylord and C. E. Tweedie. (2008). Erosion of the Barrow Environmental Observatory Coastline 2003-2007, Northern Alaska. Proceedings of the Ninth International Conference on Permafrost. Tweedie, C.E., Gaylord, A.G. 2008. Barrow Area Information Database. http://baidims.org
Online_Linkage: http://baidims.org
Online_Linkage: http://data.eol.ucar.edu/codiac/dss/id=106.ARCSS400
Description:
Abstract:
For the purposes of this study, the shoreline is defined as the bluff edge along the coast of Elson Lagoon. These data are derived from Differential Global Positioning System (DGPS) surveys.
Purpose:
Mapping is performed to monitor shoreline erosion along Elson Lagoon which is a key site of the Arctic Coastal Dynamics (ACD) program and  Arctic Circum-polar Coastal Observatory Network (ACCO-Net).
Supplemental_Information:
none
Time_Period_of_Content:
Time_Period_Information:
Range_of_Dates/Times:
Beginning_Date: 20030806
Beginning_Time: unknown
Ending_Date: 20090812
Ending_Time: unknown
Currentness_Reference:
ground condition
Status:
Progress: Complete
Maintenance_and_Update_Frequency: None planned
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -156.573094
East_Bounding_Coordinate: -156.555598
North_Bounding_Coordinate: 71.333643
South_Bounding_Coordinate: 71.310665
Keywords:
Theme:
Theme_Keyword_Thesaurus: GCMD Keywords
Theme_Keyword: Land Surface > Erosion/Sedimentation > Erosion
Theme_Keyword: Oceans > Coastal Processes > Shorelines
Theme_Keyword: Data Analysis And Visualization > Global Positioning Systems
Theme:
Theme_Keyword_Thesaurus: ISO 19115 Topic Categories
Theme_Keyword: geoscientificInformation
Theme_Keyword: elevation
Theme:
Theme_Keyword_Thesaurus: Shoreline Metadata Profile of the Content Standards for Digital Geospatial Metadata: Shoreline Glossary and Bibliography
Theme_Keyword: Bluff
Theme_Keyword: Differential Global Positioning System
Place:
Place_Keyword_Thesaurus: GCMD Keywords
Place_Keyword: Geographic Region > Arctic
Place_Keyword: Ocean > Arctic Ocean > Beaufort Sea
Place:
Place_Keyword_Thesaurus: Orth, D. J. (1967). Dictionary of Alaska place names.
Place_Keyword: Barrow
Place_Keyword: Elson Lagoon
Access_Constraints: Unrestricted
Use_Constraints:
Unrestricted
Point_of_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Craig E. Tweedie, Ph. D.
Contact_Organization: University of Texas at El Paso
Contact_Position: Assistant Professor
Contact_Address:
Address_Type: mailing and physical address
Address:
500 W. University Ave
City: El Paso
State_or_Province: Texas
Postal_Code: 79968-0555
Country: USA
Contact_Voice_Telephone: +1-915-747-8448
Contact_Electronic_Mail_Address: ctweedie@utep.edu
Browse_Graphic:
Browse_Graphic_File_Name: http://data.eol.ucar.edu/codiac/dss/id=106.ARCSS400/SectionA_August_2003_August_2008.jpg
Browse_Graphic_File_Description:
Thumbnail
Browse_Graphic_File_Type: JPEG
Data_Set_Credit:
BAID is funded by the National Science Foundation Office of Polar Programs Arctic Sciences Division (OPP0454996.)  BAID is a collaborative development effort between the Systems Ecology Lab at the University of Texas at El Paso and Nuna Technologies.  Additional funding support was provided through the US Geological Survey's Federal Geographic Data Committee.
Native_Data_Set_Environment:
Microsoft Windows XP Version 5.1 (Build 2600) Service Pack 3; ESRI ArcCatalog 9.3.1.3000
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Data_Quality_Information:
Logical_Consistency_Report:
The establishment of the 14 coastal erosion monitoring transects oriented perpendicular to the coastline as previously described by Brown et al. (2003) are used to cross-check DGPS surveys. Since 2002, the distance from fixed markers along these linear transects to the coastal bluff and thaw depths have been measured. In 2003, 2006 and 2007, these measurements were made on the same day as the August DGPS surveys. Whilst these survey methods do not permit the geospatial elucidation permissible from the repeat DGPS surveys, they are easy to perform, are part of the long-term ACD monitoring protocol and are an excellent measurement to cross-check the accuracy of the DGPS surveys.

Diurnal tidal movements are not considered to influence erosion in the Barrow area because they approximate only 0.3 m.
Completeness_Report:
Complete
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
Differential GPS data was collected. The data was processed using Trimble Geomatics Office (TGO) version 1.63 and the precision of the survey was obtained from the network adjustment report created by the software using a 95% confidence limit. The worst horizontal positional accuracy was 20 cm, with an average of less than 30 cm for the points which were collected via a continous DPGS survey.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: 10 cm
Horizontal_Positional_Accuracy_Explanation:
Accuracy estimate is based on continous surveys of the shoreline and post-processing in Trimble Geomatics Office software.
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
DGPS data is tied to the GeoID 99 model which is known to have an error of +/- 20 cm for the northern Alaska. The worst vertical positional accuracy was 22 cm, with an average of less than 10 cm, for the points which were collected via RTK continous DPGS surveys.
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: 22 cm
Vertical_Positional_Accuracy_Explanation:
Accuracy estimate is based on continous surveys of the shoreline and post-processing in Trimble Geomatics Office software.
Lineage:
Process_Step:
Process_Description:
Field data collection utilized a Trimble NetRS GPS receiver with a Zephyr Geodetic antenna as a fixed Geodetic GPS base station located at the Barrow Arctic Science Consortium (BASC). This base station provides differential correction of data files at 1 second intervals as well as real time correction to field rover GPS units within approximately five kilometers and in line of sight of site of the Trimble HPB450 radio transmitter that is connected to the base station . The base station was upgraded in 2005 from a Trimble GPS 5800, which was used during the 2003 coastal survey described below. The rover system used for 2007 surveys included a Trimble R7 with internal radio that communicated with the base station radio transmitter for real time DGPS correction and a TSC2 survey controller that logged field data. Field surveys in 2003 and 2006 utilized a Trimble 5700 receiver, Zephyr antenna and a Trimble TSC1 controller. All DGPS equipment was provided by UNAVCO (www.unavco.org) to the local science logistics provider (BASC).

A total of eight surveys of the 10.7 kilometer ACD BEO observatory were conducted. These included August 2003, 2006, June 2007, August 2007 June 2008, August 2008, June 2009 and August 2009. During each survey, field personnel walked along the top of the coastal bluff edge. The initial surveys for the 2003 season were conducted by Serbin et al (2003). In subsequent years surveys were conducted by the lead author of this paper following previously documented survey methodology documented in Serbin et al. (2003). For field surveys, the rover receiver was installed in a standard Trimble backpack configuration with the GPS antenna mounted on the bluff side of the backpack. After antenna height was corrected for the height of the field observer, this configuration allowed for the location of the horizontal and vertical position of the coastal bluff edge to be documented.

Two survey methods were used. Real Time Kinematic (RTK) surveys were conducted whenever possible. This required a radio link to the base station. RTK surveys allow for instant DGPS processing and the acquisition of centimeter-accuracy horizontal and vertical location data.  The second method utilized a Post-Processed Kinematic (PPK) survey style, which did not require a radio link, but instead relied on an unobstructed On-The-Fly (OTF) initialization period and post-survey differential correction with GPS data logged at the base station to provide field survey data with centimeter accuracy.  For both survey types, the rover receiver was set to log data at a high resolution of one-second intervals to more accurately delineate the generally irregular coastal bluff edge. Repeat surveys using these vertically and horizontally centimeter-accurate field methods provide a means to accurately monitor the geospatial dynamics of the coastal bluff edge as it changes with coastal erosion. 

DGPS survey data was downloaded from the controller and imported into Trimble Geomatic Office Software version 1.63 (TGO).  Data was exported in text files suitable for ingestion by ESRI's ArcGIS (Workstation 9.2) Geographic Information System (GIS) software. Data from PPK surveys were processed by downloading base station files that were utilized for differentially correcting data collected by the rover GPS unit using standard DGPS correction procedures. Processed data were exported as for that of the RTK surveys.

Processed DGPS survey data were imported to ArcGIS as X, Y point data and saved to a point shapefile. Erroneous points that resulted from poor GPS signal when field personnel traversed small coastal gullies were deleted. Using the polyline conversion tool in the ArcGIS extension AlaskaPak Version 2.0 for ArcGIS 9.2, point shapefiles were converted to polyline shapefiles. For each survey, the length of the coastline was computed for each of the four monitoring segments using the attribute data field calculator tool associated with the ArcGIS polyline tool. Using the polyline shapefiles as a determinant location of the coastal bluff at each survey time, polygon shapefiles were created to establish the area of coastline lost to erosion for each monitoring segment for the following survey periods: August 2003 to August 2007, August 2003 to August 2006, August 2003 to June 2007, June to August 2007, August 2003 to June 2008, August 2003 to August 2008, August 2003 to June 2009, and August 2003 to August 2009. The area of each polygon shapefile was computed using the calculate area command from ArcGIS Toolbox. Rates of erosion were calculated for the following periods mentioned above. To enhance inter-comparison of erosion rates between segments of different lengths and different sampling periods, results were normalized by the length of the coastal segment at the earliest survey associated with a given survey period and reduced to a year-long time frame for survey periods spanning the 2003 to 2006, 2007, 2008 and 2009 periods.
Process_Date: 2009
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: Adrian Aguirre
Contact_Organization: University of Texas at El Paso, Systems Ecology Lab
Contact_Position: Student, M.Sc.
Contact_Address:
Address_Type: mailing and physical address
Address:
500 W. University
City: El Paso
State_or_Province: Texas
Postal_Code: 79968-0555
Country: USA
Contact_Voice_Telephone: 915-747-8816
Contact_Electronic_Mail_Address: adragu82@hotmail.com
Contact Instructions:
Contact Dr. Tweedie if unavailable

ctweedie@utep.edu
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Spatial_Data_Organization_Information:
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: G-polygon
Point_and_Vector_Object_Count: 13
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Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Grid_Coordinate_System:
Grid_Coordinate_System_Name: Universal Transverse Mercator
Universal_Transverse_Mercator:
UTM_Zone_Number: 4
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.999600
Longitude_of_Central_Meridian: -159.000000
Latitude_of_Projection_Origin: 0.000000
False_Easting: 500000.000000
False_Northing: 0.000000
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.1
Ordinate_Resolution: 0.1
Planar_Distance_Units: meters
Geodetic_Model:
Horizontal_Datum_Name: North American Datum of 1983
Ellipsoid_Name: Geodetic Reference System 80
Semi-major_Axis: 6378137.000000
Denominator_of_Flattening_Ratio: 298.257222
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Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: SectionA_August_2003_August_2009
Entity_Type_Definition:
Polygon Attribute Table
Entity_Type_Definition_Source:
ESRI
Attribute:
Attribute_Label: FID
Attribute_Definition:
Internal feature number.
Attribute_Definition_Source:
ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition:
Feature geometry.
Attribute_Definition_Source:
ESRI
Attribute_Domain_Values:
Unrepresentable_Domain:
Coordinates defining the features.
Attribute:
Attribute_Label: Id
Attribute_Definition:
Unique Identifier
Attribute_Definition_Source:
ESRI
Attribute_Domain_Values:
Enumerated_Domain:
Enumerated_Domain_Value: Id
Enumerated_Domain_Value_Definition:
Unique Identifier
Enumerated_Domain_Value_Definition_Source:
ESRI
Attribute:
Attribute_Label: Area
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Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: National Snow and Ice Data Center
Contact_Position: NSIDC User Services
Contact_Address:
Address_Type: mailing and physical address
Address:
CIRES, 449 UCB, University of Colorado
City: Boulder
State_or_Province: CO
Postal_Code: 80309-0449
Country: USA
Contact_Voice_Telephone: 303-492-6199
Contact_Facsimile_Telephone: 303-492-2468
Contact_Electronic_Mail_Address: nsidc@nsidc.org
Resource_Description: Downloadable Data
Distribution_Liability:
The National Snow and Ice Data Center (NSIDC) shall not be held liable for improper or incorrect use of the data described and/or contained herein. The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived.  It is the responsibility of the data user to use the data appropriately and consistently within the limitations of geospatial data in general and these data in particular. Any related graphics are intended to aid the data user in acquiring relevant data; it is not appropriate to use the related graphics as data. NSIDC gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. These data and related graphics are not legal documents and are not intended to be used as such.  This disclaimer applies both to individual use of the data and aggregate use with other data.
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ArcGIS Shapefile
Format_Version_Number: 9.2
Transfer_Size: 0.087
Digital_Transfer_Option:
Online_Option:
Computer_Contact_Information:
Network_Address:
Network_Resource_Name: http://data.eol.ucar.edu/codiac/dss/id=106.ARCSS400
Fees: none
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Metadata_Reference_Information:
Metadata_Date: 20091021
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: National Snow and Ice Data Center
Contact_Position: NSIDC Metadata Manager
Contact_Address:
Address_Type: mailing and physical address
Address:
CIRES, 449 UCB, University of Colorado
City: Boulder
State_or_Province: CO
Postal_Code: 80309-0449
Country: USA
Contact_Voice_Telephone: 303-492-6199
Contact_Electronic_Mail_Address: metadata@nsidc.org
Metadata_Standard_Name: FGDC Content Standards for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Extensions:
Online_Linkage: http://www.esri.com/metadata/esriprof80.html
Profile_Name: ESRI Metadata Profile
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