AO meaning in Academic & Science ?

The Atlantic Ocean is the second-largest of the world's oceans, with an area of about 106,460,000 km2 (41,100,000 sq mi). It covers approximately 20 percent of Earth's surface and about 29 percent of its water surface area. It is known to separate the "Old World" from the "New World" in the European perception of the World.

The Atlantic Ocean occupies an elongated, S-shaped basin extending longitudinally between Europe and Africa to the east, and the Americas to the west. As one component of the interconnected World Ocean, it is connected in the north to the Arctic Ocean, to the Pacific Ocean in the southwest, the Indian Ocean in the southeast, and the Southern Ocean in the south (other definitions describe the Atlantic as extending southward to Antarctica). The Atlantic Ocean is divided in two parts, by the Equatorial Counter Current, with the North(ern) Atlantic Ocean and the South(ern) Atlantic Ocean at about 8°N.

Scientific explorations of the Atlantic include the Challenger expedition, the German Meteor expedition, Columbia University's Lamont-Doherty Earth Observatory and the United States Navy Hydrographic Office.