Climate Zones & Ocean Currents

Weather is the daily temperature and precipitation for a particular spot on a specific day. Climate is average weather for an area over long periods of time.

The Sun’s rays hit the equator more directly and for longer periods of time than other parts of Earth. Consequently, the equator has much more consistent and warmer temperatures than the rest of Earth.

Earth is heated by incoming energy from the Sun. Because Earth is round, the angle of the surface relative to the incoming radiation differs with latitude. At low latitudes, near the equator, direct overhead sunlight all year warms surface waters. At high latitudes, ocean waters receive less sunlight. These variations in solar energy mean that the ocean surface can vary in temperature from warm to very cold.

While there are five ocean basins that are named for their geographic locations, there is only one connected global ocean.

Lines of latitude are imaginary circles drawn parallel to the Equator on a globe. They are used along with lines of longitude, which run perpendicular to the Equator, to help identify specific spots on Earth.

No, there are a multitude of factors that determine a region’s climate. The atmosphere, the terrain and vegetation that are found in an area, the amount of water that is found in the area all determine the climate of an area.

The angle of the Sun causes its light to strike different latitudes with different intensities. For example, the Sun’s rays strike the Equator with greater intensity than they do the North Pole. Additionally, the sun is always directly over the Equator, as a result, this area is always much warmer than the North Pole.

The Tropic of Cancer and the Tropic of Capricorn are found at 23.5° N latitude and 23.5° S latitude. The Equator lies in the middle of these two latitudes, in the area known as the Tropical Zone. The Temperate Zones cover the area between the Tropic of Cancer and the Arctic Circle and the area between the Tropic of Capricorn and the Antarctic Circle. The Polar Zones are the areas from the Arctic or Antarctic Circles to the North and South Poles.

Ocean and air currents work together to distribute heat and moisture around Earth. Less-dense air and water rise; denser air and water sink. This creates a series of circulation systems that span the globe. These systems typically flow clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.

The Coriolis effect describes why air currents “bend” to the right or East in the Northern Hemisphere. The Coriolis effect is caused by the rotation of Earth and the speed at which it does so at different latitudes.

Water that is of a lower temperature or a higher salinity has a greater density, and sinks to the ocean floor. It is replaced by surface water, which then becomes cold and/or salty. This creates a system of deep-water and surface currents circulating around the globe.

When air rises, water vapor in the air condenses to form clouds and precipitation. This increases the moisture in the area which can lead to the formation of a rainforest. In areas where air sinks, water vapor is reduced, and the air becomes dryer. This reduction of moisture can lead to the formation of a desert.