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. 2016 Jun 1;11(6):e0155932. doi: 10.1371/journal.pone.0155932

Table 1. Description of sea ice variables used in the analysis of factors influencing the timing of arrival on shore, length of stay, and timing of departure back to sea ice by polar bears from the Southern Beaufort Sea subpopulation.

Variable Description
FD≤15% The first date (day of year) when the proportion of the continental shelf covered by >15% sea ice concentration decreased to ≤15%.
FD≤50% The first date when the proportion of the continental shelf covered by >50% sea ice concentration decreased to ≤50%.
Shelf>15%_wk The mean proportion of the shelf covered by >15% concentration sea ice 1 week prior to arrival on shore.
Shelf>50%_wk The mean proportion of the shelf covered by >50% concentration sea ice 1 week prior to arrival on shore.
Mdis>15%_wk The mean distance (km) of >15% concentration sea ice from the continental shelf 1 week prior to arrival on shore.
Mdis>50%_wk The mean distance of >50% concentration sea ice from the continental shelf 1 week prior to arrival on shore.
OW15% The duration (number of days) of the open-water season, defined as when the proportion of the continental shelf covered by >15% sea ice concentration decreases below ≤15%.
OW50% The duration of the open-water season, defined as when the proportion of the continental shelf covered by >50% sea ice concentration decreases below ≤50%.
Shelf>15%_OW The mean proportion of the continental shelf covered by >15% concentration sea ice during the open water season.
Shelf>50%_OW The mean proportion of the continental shelf covered by >50% concentration sea ice during the open water season.
Mdis>15%_OW The mean distance of >15% concentration sea ice from the continental shelf during the open water season.
Mdis>50%_OW The mean distance of >50% concentration sea ice from the continental shelf during the open water season.
LD≤15% The last date when the proportion of the continental shelf covered by >15% sea ice concentration was below ≤15%.
LD≤50% The last date when the proportion of the continental shelf covered by >50% sea ice concentration was below ≤50%.
Shelf>15%_depart The mean proportion of the continental shelf covered by >15% concentration sea ice 1 week prior to departure from shore.
Shelf>50%_depart The mean proportion of the continental shelf covered by >50% concentration sea ice 1 week prior to departure from shore.
Mdis>15%_depart The mean distance of >15% concentration sea ice from the continental shelf 1 week prior to departure from shore back to sea ice.
Mdis>50%_depart The mean distance of >50% concentration sea ice from the continental shelf 1 week prior to departure from shore back to sea ice.
Year Calendar year in which observations were collected.