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North Pole Polygon

vectorGeoJSONPolygonEPSG:4326tinybundled

A polygon encircling the north pole in EPSG:4326. Its area and centroid are wrong in any projection treating latitude/longitude as planar coordinates.

Polygon geometry of north_pole_polygon, rendered from the case's data
Polygon geometry, rendered from the case's actual geometry. Scale is normalized to the viewport and is not comparable between cases.
Property Value
Case ID north_pole_polygon
Category vector
Format GeoJSON
Geometry type Polygon
CRS EPSG:4326
Location North Pole — 90.00°W, 84.00°N → 90.00°E, 89.50°N
Test tier unit
Size class tiny
Storage class bundled
Redistributable yes
Loader geopandas
Status validated

Use this case

import pytest


@pytest.mark.geocase_case("north_pole_polygon")
def test_north_pole_polygon(geocase_case) -> None:
    data = geocase_case.load()
    assert data is not None

Use GeoCase in your tests

Install the complete set of vector, raster, and NetCDF dependencies:

pip install "geocase[all]"

View GeoCase on PyPI.

What this case checks

Ensure polygon-based utilities handle geometries near the north pole without crashing or producing wildly incorrect area calculations.

Risk types covered

Expected behavior

Assertion Expected
expect_loadable yes
expect_valid_geometry yes
expect_crs yes
expected_epsg 4326
expected_geometry_types Polygon

Notes

A GeoJSON Polygon that encircles the north pole at latitude 85°N.

Purpose

The existing north_pole_point case puts a single coordinate at 90°N, 0°E. A point is dimensionless, so it avoids the harder questions:

  • How large is the polygon's area?
  • What happens when the ring crosses the antimeridian implicitly?
  • Do reprojection routines (e.g. WGS 84 → NSIDC Polar Stereographic) keep the geometry valid?

This polygon answers those questions by providing a simple four-vertex ring whose interior includes the pole itself.

Geometry

A closed ring at 85°N with vertices at longitudes −45°, 45°, 135°, and −135°. The ring is wound counter-clockwise (right-hand rule) and encloses the pole.

Edge-case value

Concern Detail
Area distortion Equirectangular area is wildly wrong near the pole
Reprojection Some CRS transformations clip or distort polar polygons
Antimeridian crossing The ring implicitly crosses 180° longitude
Rendering Map tiles in Web Mercator cannot show latitudes beyond ~85.06°

Required capabilities

  • load
  • geometry-validation
  • reprojection

Files

Browse this case on GitHub

Source and license

  • Source: geocase-curated
  • License: MIT

Tags

crs edge_case geojson north_pole polar pole polygon vector