The Doldrums, also called the "equatorial calms", is a nautical term for the intertropical convergence zone The ITCZ was originally identified from the 1920s to the 1940s as the "Intertropical Front" , but after the recognition in the 1940s and 1950s of the significance of wind field convergence in tropical weather production, the term "ITCZ" was then applied, with special reference to the light and variable nature of the winds.[1] It affects areas of the Atlantic Ocean The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about 106.4 million square kilometres , it covers approximately one-fifth of the Earth's surface and about one-quarter of its water surface area. The first part of its name refers to the Atlas of Greek mythology, making the Atlantic the "Sea of, the Pacific Ocean The Pacific Ocean is the largest of the Earth's oceanic divisions. Its name is derived from the Luso-Latin macaronic Tepre Pacificum, "peaceful sea", bestowed upon it by the Portuguese explorer Ferdinand Magellan[citation needed]. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in and the Indian Ocean The Indian Ocean is the third largest of the world's oceanic divisions, covering about 20% of the water on the Earth's surface. It is bounded on the north by South Asia ; on the west by Africa; on the east by Indochina, the Sunda Islands, and Australia; and on the south by the Southern Ocean (or, depending on definition, by Antarctica) that are within the Intertropical Convergence Zone The ITCZ was originally identified from the 1920s to the 1940s as the "Intertropical Front" , but after the recognition in the 1940s and 1950s of the significance of wind field convergence in tropical weather production, the term "ITCZ" was then applied, a low-pressure area around the equator The equator is the intersection of the Earth's surface with the plane perpendicular to the Earth's axis of rotation and containing the Earth's center of mass. In simpler language, it is an imaginary line on the Earth's surface equidistant from the North Pole and South Pole that divides the Earth into a Northern Hemisphere and a Southern Hemisphere, where the prevailing winds In meteorology, prevailing winds are winds that blow predominantly from a single general direction over a particular point on the Earth's surface. The dominant winds are the trends in direction of wind with the highest speed over a particular point on the Earth's surface. A region's prevailing and dominant winds are often affected by global are calm. The low pressure is caused by the heat at the equator, which makes the air rise and travel north and south high in the atmosphere, until it subsides again in the horse latitudes Horse latitudes or Subtropical High are subtropic latitudes between 30 and 35 degrees both north and south. This region, under a ridge of high pressure called the subtropical high, is an area which receives little precipitation and has variable winds mixed with calm. Some of that air returns to the Doldrums through the trade winds The trade winds are the prevailing pattern of easterly surface winds found in the tropics, within the lower portion of the Earth's atmosphere, in the lower section of the troposphere near the Earth's equator. The trade winds blow predominantly from the northeast in the Northern Hemisphere and from the southeast in the Southern Hemisphere,. This process can lead to light or variable winds and more severe weather, in the form of heavy squalls, thunderstorms and hurricanes. It is the area of low pressure near the equator, but some get confused with saying it is the winds associated with the inter tropical convergence zone.
Reputation
This region is also noted for extremely calm periods when the winds disappear altogether, or are light and shifting. Hurricanes A tropical cyclone is a storm system characterized by a large low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones feed on heat released when moist air rises, resulting in condensation of water vapor contained in the moist air. They are fueled by a different heat mechanism than other cyclonic originate in this region. Because of the unpredictable weather patterns, the Doldrums became notorious with sailors because this region's periods of deadly calm could trap ships for days or weeks on end as they waited for enough wind to power their sails.
Even today the doldrums have a nasty reputation and may cause unexpected delays for the circumnavigators To circumnavigate, to navigate a circumference, such as an island, a continent, or the Earth, is to travel all the way around the edge, particularly when in control of the route taken. It is a term used very much to describe travelling all the way around the world by any method. Yachts may get stuck to the intertropical convergence zone for days for seeking suitable winds.
In language
In colloquial usage, "being in the doldrums" refers to being in a state of listlessness, despondency, inactivity, stagnation, or a slump, as characterised in Coleridge Samuel Taylor Coleridge (21 October 1772 – 25 July 1834) was an English poet, Romantic, literary critic and philosopher who, with his friend William Wordsworth, was one of the founders of the Romantic Movement in England and one of the Lake Poets. He is probably best known for his poems The Rime of the Ancient Mariner and Kubla Khan, as well as's The Rime of the Ancient Mariner The Rime of the Ancient Mariner is the longest major poem by the English poet Samuel Taylor Coleridge, written in 1797–98 and published in the first edition of Lyrical Ballads in 1798 (see 1798 in poetry). The modern editions use a later revised version printed in 1817 that featured a gloss. Along with other poems in Lyrical Ballads, it was a:
All in a hot and copper sky, The bloody Sun, at noon, Right up above the mast did stand, No bigger than the Moon. Day after day, day after day, We stuck, nor breath nor motion; As idle as a painted ship Upon a painted ocean.
References
- ^ "Doldrums". Glossary of Meteorology. American Meteorological Society The American Meteorological Society promotes the development and dissemination of information and education on the atmospheric and related oceanic and hydrologic sciences and the advancement of their professional applications. Founded in 1919, the American Meteorological Society has a membership of more than 11,000 professionals, professors,. http://amsglossary.allenpress.com/glossary/search?p=1&query=doldrums. Retrieved 2009-06-04.
Categories: Tropical meteorology | Nautical terms Categories: Sailing | Terminology | Water transport
mallorcaphotoblog
Fri, 20 Nov 2009 07:20:09 GM
On a trip to Palma de Mallorca you may have noticed over the last three or four weeks a large yellow vessel anchoring in the Bahia de Palma. The cargo ship Pilar del Mar is anchored in the bay, perhaps 200 metres from the shore. ...
