The Borborema Plateau ( Portuguese Planalto da Borborema , also known as the Serra da Borborema ) is a plateau in northeastern Brazil which extends across the states of Pernambuco , Paraíba , and Rio Grande do Norte . The plateau is the northeasternmost portion of the Brazilian Highlands and is the most relevant watershed of its region. It ranges approximately 400 kilometres (250 mi) from north to south and 200 kilometres (120 mi) from east to west. More than 100 rivers originate from the plateau, including the Moxotó , Mundaú , Pajeú , Paraíba do Norte , Seridó , and Una .
17-600: The Borborema Plateau serves as an orographic barrier, despite its relatively low elevation, against the moist easterly winds of the Atlantic Ocean . Areas west of the plateau, which make up part of the sertão , are arid and prone to drought. The Pajeú River , the largest tributary of the São Francisco River , originates from the Borborema. The Borborema Plateau is part of a huge anastomosing shear zone . The plateau
34-602: Is a major factor for meteorologists to consider when they forecast the local weather. Orography can play a major role in determining the type, amount, intensity, and duration of precipitation events. Researchers have discovered that barrier width, slope steepness, and updraft speed are major contributors when it comes to achieving the optimal amount and intensity of orographic precipitation. Computer models simulating these factors have shown that narrow barriers and steeper slopes produce stronger updraft speeds, which in turn increase orographic precipitation. Orographic precipitation
51-423: Is being lifted expands and cools adiabatically. This adiabatic cooling of a rising moist air parcel may lower its temperature to its dew point , thus allowing for condensation of the water vapor contained within it, and hence the formation of a cloud . If enough water vapor condenses into cloud droplets, these droplets may become large enough to fall to the ground as precipitation. Terrain-induced precipitation
68-408: Is composed primarily of igneous and metamorphic rock. This Paraíba , Brazil location article is a stub . You can help Misplaced Pages by expanding it . This Pernambuco , Brazil location article is a stub . You can help Misplaced Pages by expanding it . This Rio Grande do Norte , Brazil location article is a stub . You can help Misplaced Pages by expanding it . Orography Orography
85-655: Is known to occur on oceanic islands , such as the Hawaiian Islands and New Zealand ; much of the rainfall received on such islands is on the windward side, and the leeward side tends to be quite dry, almost desert -like. This phenomenon results in substantial local gradients in the amount of average rainfall, with coastal areas receiving on the order of 20 to 30 inches (510 to 760 mm) per year, and interior uplands receiving over 100 inches (2,500 mm) per year. Leeward coastal areas are especially dry—less than 20 in (510 mm) per year at Waikiki —and
102-482: Is the study of the topographic relief of mountains , and can more broadly include hills, and any part of a region's elevated terrain. Orography (also known as oreography , orology, or oreology ) falls within the broader discipline of geomorphology . The term orography comes from the Greek : όρος , hill, γράφω , to write. Mountain ranges and elevated land masses have a major impact on global climate. For instance,
119-456: The Age of Sail , a vessel always sought to use the wind to its advantage, maneuvering if possible to attack from windward. This was particularly important for less maneuverable square-rigged warships, which had limited ability to sail upwind, and sought to "hold the weather gage " entering battle. This was particularly important once artillery was introduced to naval warfare. Ships heel away from
136-424: The Age of Sail , the term weather was used as a synonym for windward in some contexts, as in the weather gage . Since it captures rainfall , the windward side of a mountain tends to be wetter than the leeward side it blocks. The drier leeward area is said to be in a rain shadow . The term "windward" has roots in both Low German and Old English. The word "lee", which means a place without wind, comes from
153-406: The wind . Windward is upwind from the point of reference, i.e., towards the direction from which the wind is coming; leeward is downwind from the point of reference, i.e., along the direction towards which the wind is going. The side of a ship that is towards the leeward is its "lee side". If the vessel is heeling under the pressure of crosswind , the lee side will be the "lower side". During
170-543: The Old Norse "hle" for "cover" and has been used in marine navigation in Germany since medieval times. The word "wind," meaning "air in motion," comes from Proto-Germanic *winda- and has evolved over time, with pronunciation changes influenced by similar words like "windy." The word "wind" has been associated with emptiness and vanity since the late 13th century. Additionally, "wind" has been used figuratively in phrases like "which way
187-468: The elevated areas of East Africa substantially determine the strength of the Indian monsoon . In scientific models, such as general circulation models , orography defines the lower boundary of the model over land. When a river's tributaries or settlements by the river are listed in 'orographic sequence', they are in order from the highest (nearest the source of the river) to the lowest or mainstem (nearest
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#1732851058627204-467: The mouth). This method of listing tributaries is similar to the Strahler Stream Order , where the headwater tributaries are listed as category 1. Orographic precipitation, also known as relief precipitation, is precipitation generated by a forced upward movement of air upon encountering a physiographic upland (see anabatic wind ). This lifting can be caused by: Upon ascent, the air that
221-506: The same meaning are widely used, particularly upwind and downwind . Among sailing craft, the windward vessel is normally the more maneuverable. For this reason, rule 12 of the International Regulations for Preventing Collisions at Sea , applying to sailing vessels, stipulates that where two are sailing in similar directions in relation to the wind, the windward vessel gives way to the leeward vessel. In naval warfare during
238-500: The tops of moderately high uplands are especially wet—about 475 in (12,100 mm) per year at Wai'ale'ale on Kaua'i . Another area in which orographic precipitation is known to occur is the Pennines in the north of England : the west side of the Pennines receives more rain than the east because the clouds are forced up and over the hills and cause the rain to tend to fall on
255-418: The western slopes. This is particularly noticeable between Manchester (to the west) and Leeds (to the east); Leeds receives less rain due to a rain shadow of 12 miles (19 km) from the Pennines. Leeward In geography and seamanship , windward ( / ˈ w ɪ n d w ər d , ˈ w ɪ n ər d / ) and leeward ( / ˈ l iː w ər d , ˈ lj uː ər d / ) are directions relative to
272-648: The wind blows" to indicate the current state of affairs. The suffix "-ward," meaning "toward," is an adverbial suffix in Old English derived from Proto-Germanic *werda-, which itself comes from the PIE root *wer- meaning "to turn, bend." The original notion of "-ward" is "turned toward." Windward and leeward directions (and the points of sail they create) are important factors to consider in such wind-powered or wind-impacted activities as sailing , wind-surfing , gliding , hang-gliding , and parachuting . Other terms with broadly
289-419: The wind, so the leeward vessel would expose more of her topsides to shot, in extreme cases even part of her bottom. The terms windward and leeward are used in reference both to sides (and climates ) of individual islands and relative island locations in an archipelago . The windward side of an island is subject to the prevailing wind , and is thus the wetter (see orographic precipitation ). The leeward side
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