Polar Circles
E572577
Polar Circles are the high-latitude boundary lines near the Earth's poles that mark the regions experiencing at least one day of continuous daylight and one day of continuous darkness each year.
Observed surface forms (2)
| Surface form | Occurrences |
|---|---|
| Arctic Circle | 0 |
| Antarctic Circle | 0 |
Statements (48)
| Predicate | Object |
|---|---|
| instanceOf |
geographical concept
ⓘ
line of latitude ⓘ polar circle ⓘ |
| approximateLatitudeDegrees |
66.5° N
ⓘ
66.5° S ⓘ |
| centeredOn |
geographic North Pole
NERFINISHED
ⓘ
geographic South Pole NERFINISHED ⓘ |
| complementaryTo |
Tropic of Cancer
NERFINISHED
ⓘ
Tropic of Capricorn NERFINISHED ⓘ |
| coordinateSystem | geographic coordinate system ⓘ |
| definedBy | Earth’s axial tilt relative to its orbital plane ⓘ |
| definedRelativeTo |
Earth’s axial tilt
ⓘ
Earth’s axial tilt ⓘ |
| enclosesRegionWith |
midnight sun
ⓘ
midnight sun ⓘ polar night ⓘ polar night ⓘ |
| haveNumber | 2 ⓘ |
| include |
one northern polar circle
ⓘ
one southern polar circle ⓘ |
| latitudeDependsOn | obliquity of the ecliptic ⓘ |
| latitudeVariesOver | geological timescales ⓘ |
| locatedIn |
Northern Hemisphere
ⓘ
Southern Hemisphere ⓘ |
| markRegionWith |
at least one day of continuous darkness per year
ⓘ
at least one day of continuous daylight per year ⓘ |
| oppositeTo | Tropics NERFINISHED ⓘ |
| parallelType |
major circle of latitude
ⓘ
major circle of latitude ⓘ |
| passesThrough |
Alaska
NERFINISHED
ⓘ
Antarctica NERFINISHED ⓘ Arctic Ocean NERFINISHED ⓘ Canada NERFINISHED ⓘ Finland NERFINISHED ⓘ Greenland NERFINISHED ⓘ Iceland NERFINISHED ⓘ Norway NERFINISHED ⓘ Russia NERFINISHED ⓘ Southern Ocean NERFINISHED ⓘ Sweden NERFINISHED ⓘ |
| planetaryContext | Earth NERFINISHED ⓘ |
| refersTo |
Antarctic Circle
NERFINISHED
ⓘ
Arctic Circle NERFINISHED ⓘ |
| relatedToPhenomenon |
seasonal variation in daylight
ⓘ
solar elevation angle extremes ⓘ |
| separate | mid-latitudes from polar regions ⓘ |
| usedIn |
climate classification
ⓘ
definition of polar regions ⓘ |
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.