Equator: The plane perpendicular to Earth's polar axis, which divides Earth into two hemispheres, north and south. The extension of this plane into space forms the celestial equator.

 

Related Words

Equator: The geographic circle at 0 degrees latitude on the earth's surface. It is equal distance from the North and South Poles and divides the Northern Hemisphere from the Southern.

Equatorial Undercurrent: A subsurface current setting eastward along the Equator in the Pacific, Atlantic, and Indian Oceans. In the Pacific, its core of maximum velocity lies at a depth of about 100 meters within t . . . View Full Definition

Equatorial Tides: Tides occurring semimonthly as a result of the Moon being over the Equator. At these times the tendency of the Moon to produce a diurnal inequality in the tide is at a minimum.

Equatorial Countercurrent: A current setting eastward between the North and South Equatorial Currents of the Atlantic, Pacific, and Indian (in northern winter) Oceans. In the Atlantic and Pacific, its axis lies about . . . View Full Definition

North Equatorial Current: A current setting west-ward in the North Atlantic and North Pacific Oceans and in the Indian Ocean from about October to July. It occurs immediately north of the Equatorial Counter Current.

Equatorial Tidal Currents: Tidal currents occurring semimonthly as a result of the Moon being over the Equator. At these times the tendency of the Moon to produce a diurnal inequality in the tidal current is at a minimum.

Celestial Equator: The projection of the plane of the geographical equator upon the celestial sphere.

South Equatorial Current: A current setting west-ward along and south of the Equator in the Atlantic and Pacific Oceans, and south of the Equator in the Indian Ocean. It occurs immediately south of the Equatorial Cou . . . View Full Definition

Equatorial Trough: The quasi-continuous area of low pressure between the subtropical high pressure areas in both the Northern and Southern Hemisphere.

Equatorial Arcs: A method of progressing house cusps, based upon the Earth's rotation, in which one year of life corresponds to the passage of 1° right ascension over the meridian, approximately four minutes . . . View Full Definition