Daily Ice Edge

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A. Naming Conventions and unpacking
B. Resolution
C. Analysis Process
D. Contact information

A. Naming Conventions and General Information:
nic_autoc_[yyyjjj]_[pl]_[a].tar where autoc is the name of the product from NATICE. 4 digit year, 3 digit julian polygon version as described in WMO SIGRID 3

Unpacking:
The data was tar'ed using a Linux machine.
To untar on windows, use winzip;
To untar on Linux,
type: tar xfv nic_auto<c><yyyyjjj>_<pl>_<a>.tar
There will be 3 files present: *.shp, *.shx, and *.dbf.

B. Resolution:
The resolution of the intial product is 25km. However, this resolution is relative due to the nature of the shape file in GIS software. Further, inputs to the data can range in resolution from 200m to 25km. These inputs include RADARSAT, DMSP OLS, AVHRR, and QUIKSCAT. The SSM/I contour uses the NASA Team 2 algorithm and is contoured using the 10.1% value.
In the Lowgrain Ice Edge, the information is removed at a 2000 meter interval to provide a smaller, more portable product.

C. Analysis Process:
1. NIC ice analysts bring the SSM/I automated contour into the Sea Ice Mapping System (SIMS) as a shapefile and verify the contour using imagery (Quickscat, SSM/I, Visible/IR, or RADARSAT). Analysts value add to the automated edge by adjusting the position of the contour based on available imagery.

2. The value-added iceedge shapefile, shoreline shapeline file and attribute shapefile are then merged into a single coverage file. The coverage is cleaned and quality controlled in Arctools Edit. An AML is then run to create the separate Northern and Southern hemispheric ice edge.
Due to varying system properties, please consult your imaging manual for printing instructions.