Trade winds in the context of "Subtropical ridge"

The horse latitudes are the latitudes about 30 degrees north and south of the equator. They are characterized by sunny skies, calm winds, and very little precipitation. They are also known as subtropical ridges or highs. It is a high-pressure area at the divergence of trade winds and the westerlies.

The Walker circulation, also known as the Walker cell, is a conceptual model of the air flow in the tropics in the lower atmosphere (troposphere). According to this model, parcels of air follow a closed circulation in the zonal and vertical directions. This circulation, which is roughly consistent with observations, is caused by differences in heat distribution between ocean and land. In addition to motions in the zonal and vertical direction the tropical atmosphere also has considerable motion in the meridional direction as part of, for example, the Hadley Circulation.

The Walker circulation is associated with the pressure gradient force that results from a high pressure system over the eastern Pacific Ocean, and a low pressure system over Indonesia. The Walker circulations of the tropical Indian, Pacific, and Atlantic basins result in westerly surface winds in northern summer in the first basin and easterly winds in the second and third basins. As a result, the temperature structure of the three oceans display dramatic asymmetries. The equatorial Pacific and Atlantic both have cool surface temperatures in northern summer in the east, while cooler surface temperatures prevail only in the western Indian Ocean. These changes in surface temperature reflect changes in the depth of the thermocline.

The monsoon trough is a convergence zone between the wind patterns of the southern and northern hemispheres. It is a portion of the Intertropical Convergence Zone in the Western Pacific, and is depicted by a line on a weather map showing the locations of minimum sea level pressure.

Westerly monsoon winds lie in its equatorward portion while easterly trade winds exist poleward of the trough. Right along its axis, heavy rains can be found which usher in the peak of a location's respective rainy season. The monsoon trough plays a role in creating many of the world's rainforests.

The Intertropical Convergence Zone (ITCZ /ɪtʃ/ ITCH, or ICZ), known by sailors as the doldrums or the calms because of its monotonous windless weather, is the area where the northeast and the southeast trade winds converge. It encircles Earth near the thermal equator, though its specific position varies seasonally. When it lies near the geographic equator, it is called the near-equatorial trough. Where the ITCZ is drawn into and merges with a monsoonal circulation, it is sometimes referred to as a monsoon trough (a usage that is more common in Australia and parts of Asia).

A tropical marine climate is a tropical climate that is primarily influenced by the ocean. It is usually experienced by islands and coastal areas 10° to 20° north and south of the equator. There are two main seasons in a tropical marine climate: the wet season and the dry season. The annual rainfall is 1000 to over 1500 mm (39 to 59 inches). The temperature ranges from 20 to 35 °C (68 to 95 °F). Under the Köppen climate classification, a "tropical marine climate" would fall under Af or Am, tropical rainforest or tropical monsoon climate. The trade winds blow all year round and are moist, as they pass over warm seas. These climatic conditions are found, for example, across the Caribbean, the eastern coasts of Brazil, Madagascar and Queensland; and many islands in tropical waters.

Kahoʻolawe is the smallest of the eight main volcanic islands of the Hawaiian Islands. Unpopulated, it lies about seven miles (11 km) southwest of Maui. The island is 11 mi (18 km) long by 6.0 mi (9.7 km) wide, with a total land area of 44.97 sq mi (116.47 km). Its highest point is the crater of Lua Makika, at the summit of Puʻu Moaulanui, about 1,477 feet (450 m) above sea level.

Kahoʻolawe is relatively dry, with an average annual rainfall of less than 26 in (66 cm) resulting from a combination of being too low to generate much orographic precipitation from the northeastern trade winds and lying in the rain shadow of eastern Maui's 10,023-foot-high (3,055 m) volcano, Haleakalā. More than one quarter of Kahoʻolawe has been eroded down to saprolitic hardpan soil, largely on exposed surfaces near the summit.

The North Pacific Gyre (NPG) or North Pacific Subtropical Gyre (NPSG), located in the northern Pacific Ocean, is one of the five major oceanic gyres. This gyre covers most of the northern Pacific Ocean. It is the largest ecosystem on Earth, located between the equator and 50° N latitude, and comprising 20 million square kilometers. The gyre has a clockwise circular pattern and is formed by four prevailing ocean currents: the North Pacific Current to the north, the California Current to the east, the North Equatorial Current to the south, and the Kuroshio Current to the west. It is the site of an unusually intense collection of human-created marine debris, known as the Great Pacific Garbage Patch.

The North Pacific Subtropical Gyre and the much smaller North Pacific Subpolar Gyre make up the two major gyre systems in the mid-latitudes of the Northern Pacific Ocean. This two-gyre circulation in the North Pacific is driven by the trade and westerly winds. This is one of the best examples of all of Earth's oceans where these winds drive a two-gyre circulation. Physical characteristics like weak thermohaline circulation in the North Pacific and the fact that it is mostly blocked by land in the north, also help facilitate this circulation. As depth increases, these gyres in the North Pacific grow smaller and weaker, and the high pressure at the center of the Subtropical Gyre will migrate poleward and westward.