Natural Cycles On a Global Scale

Six cycles are considered here which have significant effects upon Florida’s waters: The Hydrologic Cycle, The Nitrogen Cycle, The Phosphorus Cycle, The Carbon Cycle, El Niño and La Niña, and Global Warming. Each of these cycles is the result of natural and human influences occurring throughout the world.

Natural Cycles

In the discussions of the natural cycles, when the Trade Winds, for example, are changed by phenomena such as variations in ocean temperature or abnormally strong winds, El NiñoName given to the occasional development of warm ocean surface waters along the coast of Ecuador and Peru. When this warming occurs the tropical Pacific trade winds weaken and the usual upwelling of cold, nutrient rich deep ocean water off the coast of Ecuador and Peru is reduced. The El Niño normally occurs around Christmas and lasts usually for a few weeks to a few months. Sometimes an extremely warm event can develop that lasts for much longer time period or La Niña(Also sometimes called El Viejo) Is the opposite of El Niño. La Niña occurs when stronger than normal trade winds stir up cooler water from the ocean depths. weather effects are caused. The description of the Hydrologic or water cycle principles are the same even though the frequency or severity of storms may be changed by the Niño/Niña cycles operating according to their own different periodic timing. The Nitrogen and Phosphorous cycles are discussed as they give rise to the presence of nutrientsAny food, chemical element or compound an organism requires to live, grow, or reproduce. which influence what grows in our water resources and can have a significant effect upon water qualityA term used to describe the chemical, physical, and biological characteristics of water, usually in respect to its suitability for a particular purpose..

Global warming is a cycle over a long period of time that the Niño/Niña cycles may progressively become affected by global warming.

Trade Winds

The name Trade Winds reflect the paths sailed by the sailing ships that carried goods, and the routes chosen by them to catch the wind, and make better (more competitive) speeds from place to place.

For example, in general terms, air rises over the warmer parts of the earth in the Tropics and descends as it cools and spreads at altitude from the equator northwards and south. The rotation of the earth imparts a twist (or Coriolis EffectThe observed effect of the Coriolis force, especially the deflection of an object moving above the earth, rightward in the northern hemisphere and leftward in the southern hemisphere.) to change the north and south components of the general direction of the air movement to give rise to the general effect we refer to as the Trade Winds. At the surface, rising air gives rise to lower air pressures and descending air to higher pressures. Thus at the surface of the earth, the trade winds are a pattern of winds that are found in bands around the Earth's equatorial region. The trade winds are the prevailing winds in the tropics, blowing from the high-pressure area in the horse latitudes towards the low-pressure area around the equator. The trade winds blow predominantly from the northeast in the northern hemisphere and from the southeast in the southern hemisphere.

In the zone between about 30° N. and 30° S., the surface air flows toward the equator and the flow aloft is poleward. A low-pressure area of calm, light variable winds near the equator is known to mariners as the doldrums. Around 30° N. and S., the poleward flowing air begins to descend toward the surface in subtropical high-pressure belts. The sinking air is relatively dry because its moisture has already been released near the Equator above the tropical rain forests. Near the center of this high-pressure zone of descending air, called the "Horse latitudes", the winds at the surface are weak and variable. The name for this area is believed to have been given by colonial sailors, who, becalmed sometimes at these latitudesThe angular distance north or south of the earth's equator, measured in degrees along a meridian, as on a map or globe. A region of the earth considered in relation to its distance from the equator: temperate latitudes. while crossing the oceans with horses as cargo, were forced to throw some overboard to conserve water.

The surface air that flows from these subtropical high-pressure belts toward the Equator is deflected toward the west in both hemispheres by the Coriolis effect. Because winds are named for the direction from which the wind is blowing, these winds are called the northeast trade winds in the Northern Hemisphere and the southeast trade winds in the Southern Hemisphere. The trade winds meet at the doldrums. Surface winds known as " westerlies" flow from the Horse Latitudes toward the poles. The "westerlies" meet "easterlies" from the polar highs at about 50-60° N. and S.