# Arctic and Antarctic map-label sources and limitations

These GeoJSON point locations are **editorial label anchors**, not mapped
boundaries, navigable river geometries, guaranteed coast intersections, or
current locations of sea-ice openings. The editable master is
`scripts/feature_labels.csv`. The metadata field `kind` distinguishes
`river`, `estuary`, `polynya` and `ice_shelf`.

- **Major Arctic rivers and estuaries:** representative river-mouth sites
  informed by the [Arctic Ocean Model Intercomparison Project (AOMIP)](https://www2.whoi.edu/site/aomip/data/river-runoff-forcing-data/)
  and published work on Arctic river deltas. Location coordinates are
  approximate **label positions**.
- **Recurring Arctic polynyas:** [Canadian Coast Guard, Ice Navigation in Canadian Waters, chapter 3](https://www.canada.ca/en/canadian-coast-guard/corporate/publications/ice-navigation-in-canadian-waters/chapter-3-ice-climatology-environmental-conditions.html).
  The Northeast Water polynya is an **annually recurring summertime** feature:
  [Bennett et al. 2024, JGR Oceans](https://doi.org/10.1029/2023JC020513).
  Other sea-ice openings are variable in position and season. A displayed
  polynya **name is never evidence of open water at the current satellite time**.
- **Antarctic ice-shelf names:** [Australian Antarctic Program](https://www.antarctica.gov.au/about-antarctica/ice-and-atmosphere/sea-ice/fast-ice/ice-shelves/).
  Ice-shelf fronts/areas can evolve; no current shelf boundaries are depicted.
- **Coastlines:** © OpenStreetMap contributors (ODbL 1.0), from
  [OSMCoastline](https://osmdata.openstreetmap.de/data/coastlines.html).
  See [LICENSE_OSM.txt](LICENSE_OSM.txt).

Before any scientific publication, check spelling, naming conventions,
regional interpretation and display anchors. This viewer is not for navigation.