Feature Type

Feature Type Name

Polynya

Synonyms

Definition

Any water in pack ice or fast ice other than a lead, not large enough to be called open water. If a polynya is found in the same region every year, e.g. of the mouths of big rivers, it is called a recurring polynya. A temporary small clearing in pack ice which consists of small floes and brash in continuous local movement is called an unstable polynya; an opening which is flanked by large floes and therefore appears to be relatively stable is called a stable polynya. When frozen over, a polynya becomes an ice shylight from the point of view of the submariner.

Comments

Table Name

POLYNYA

Australia's Implementation Table Names

  • POLYNYA_PY

The following have been used in the definition of this feature type

  • Armstrong, T., Roberts, B. and Swithinbank, C. - Illustrated Glossary of Snow and Ice, Cambridge Press for Scott Polar Research Institute, 1966

The following have been used in categorising this feature type

  • Geography
  • Ice Features
  • Oceanography
Code Name Definition   Data type Values UoM Used by these Feature Types
1042 Dataset_Id An unique identifier of the dataset the feature belongs to Mandatory number(4)     Types
1045 Date_Capture The date the feature was captured Optional date     Types
1249 Date_Flag The type of date been stored, i.e.whether the date is approximate or definite, and for which component of the date is approximate or definite. Also includes seasons Optional character(50)
label Definition
Appoximate day in a known month and year
Approximate month in a known year The entry must be a full date, e.g. 1/1/2002, but only the month and year are valid.
Approximate season of a known year The season must be an Antarctic summer, autumn, winter or spring season. Enter season date with the approximate date of the middle of the season. Eg for spring 2002, enter as 15/10/2002.
Approximate year The entry must be a full date, e.g. 1/1/2002, but only the year is valid.
Definite day, month and year
Definite month and year The entry must be a full date, e.g. 1/1/2002, but only the month and year are valid.
Definite season and year The season must be an Antarctic summer, autumn, winter or spring season. Enter season date with the approximate date of the middle of the season. Eg for spring 2002, enter as 15/10/2002.
Definite year The entry must be a full date, e.g. 1/1/2002, but only the year is valid.
Pre year The entry must be a full date, e.g. 1/1/2002, but only the year is valid. The data was sourced before the year listed.
Unknown Value indicating that an attribute is not applicable or that it is impossible to determine
  Types
1150 Q_Info An unique identifier pointing to additional data quality information not included in the metadata record. Mandatory number(5)     Types
1090 SCAR_Gaz_Id Reference number as in the SCAR Composite Gazetteer of Antarctica Optional number(10)     Types
1127 SCAR_Name A placename name in the SCAR Composite Gazetteer of Antarctica. These names have been contributed by national gazetteers. Optional character(100)     Types