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1981–82 South-West Indian Ocean Cyclone Season
The 1981–82 South-West Indian Ocean cyclone season was a destructive and deadly cyclone season that occurred in Madagascar, where four cyclones killed 100 people and caused $250 million (USD) in damage. The season was fairly active, lasting from October to May. There were nine named storms that attained gale-force winds, or at least . Five of the storms attained tropical cyclone status, which have 10-minute sustained winds of at least . The first storm was Tropical Cyclone Alex, which was named by the Australian Bureau of Meteorology (BoM). this was due to the boundary of the basin at the time, which incorporated the Indian Ocean south of the equator and extended from the east coast of Africa to 80° E; the eastern extent was later moved to 90° E. Two other storms – Armelle and Damia – also originated in the Australian basin. The latter was the strongest cyclone on record in the basin at the time by barometric pressure, estimated at . The first storm ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1979–80 South-West Indian Ocean Cyclone Season
The 1979–80 South-West Indian Ocean cyclone season was an above-average cyclone season, and is most notable for featuring the wettest tropical cyclone ever recorded, Cyclone Hyacinthe. The season officially ran from November 1, 1979, to April 30, 1980. Systems ImageSize = width:800 height:215 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:250 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/11/1979 till:30/04/1980 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/11/1979 Colors = id:canvas value:gray(0.88) id:GP value:red id:ZD value:rgb(0,0.52,0.84) legend:Zone_of_Disturbed_Weather/Tropical_Disturbance_=_≤31_mph_(≤50_km/h) id:TD value:rgb(0.43,0.76,0.92) legend:Tropical_Depression/Subtropical_Depression_=_32–38_mph_(51–62_km/h) id:TS value:rgb(0.30,1,1) legend:Moderate_Tropical_Storm_=_39–54_mph_(63–88_km/h) id:ST value:rgb(0.75,1,0.75) l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dvorak Technique
The Dvorak technique (developed between 1969 and 1984 by Vernon Dvorak) is a widely used system to estimate tropical cyclone intensity (which includes tropical depression, tropical storm, and hurricane/typhoon/intense tropical cyclone intensities) based solely on visible and infrared Weather satellite, satellite images. Within the Dvorak satellite strength estimate for tropical cyclones, there are several Pattern recognition, visual patterns that a cyclone may take on which define the upper and lower bounds on its intensity. The primary patterns used are curved rainband, band pattern (T1.0-T4.5), Wind shear#Effects on tropical cyclones, shear pattern (T1.5–T3.5), central dense overcast (CDO) pattern (T2.5–T5.0), central cold cover (CCC) pattern, banding eye pattern (T4.0–T4.5), and Eye (cyclone), eye pattern (T4.5–T8.0). Both the central dense overcast and embedded eye pattern use the size of the CDO. The CDO pattern intensities start at T2.5, equivalent to minimal trop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1981–82 Australian Region Cyclone Season
The 1981–82 Australian region cyclone season was an average season. It officially started on 1 November 1981, and officially ended on 30 April 1982. __TOC__ Seasonal summary ImageSize = width:800 height:200 PlotArea = top:10 bottom:80 right:20 left:20 Legend = columns:3 left:30 top:58 columnwidth:270 AlignBars = early DateFormat = dd/mm/yyyy Period = from:01/11/1981 till:01/06/1982 TimeAxis = orientation:horizontal ScaleMinor = grid:black unit:month increment:1 start:01/11/1981 Colors = id:canvas value:gray(0.88) id:GP value:red id:TL value:rgb(0.43,0.76,0.92) legend:Tropical_Low_=_<63_km/h_(<39_mph) id:C1 value:rgb(0.3,1,1) legend:Category_1_=_63–88_km/h_(39-55_mph) id:C2 value:rgb(0.75,1,0.75) legend:Category_2_=_89–117_km/h_(55-73_mph) id:C3 value:rgb(1,0.85,0.55) legend:Category_3_=_118–159_km/h_(73-99_mph) id:C4 value:rgb(1,0.45,0.54) legend:Category_4_=_160–199_km/h_(99-124_mph) id:C5 value:rgb(0.55 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antsiranana
Antsiranana ( ), named Diego-Suarez prior to 1975, is a city in the far north of Madagascar. Antsiranana is the capital of Diana Region. It had an estimated population of 115,015 in 2013. History At the beginning of the 16th century, a Portuguese squadron of 13 ships crisscrossed the Indian Ocean; One of these ships went adrift, and its captain, Diogo Dias, was therefore the first European to discover the island on August 10, 1500, which he named Isle of Saint Lawrence. In February 1506, Admiral Fernão Soares recognized the place and so Antomabokala, former capital of Ankarana, acquired its name of Diego Suarez (Diogo Soares, in Portuguese), which comes from the junction of the first name of the captain and the surname of the Admiral. In 1635, the bay was mentioned for the first time under this name by the French pilot Berthelot, author of an oriental map of Africa and Madagascar. In 1824, the bay was explored by the English hydrographer Owen, then in 1833, Captain Bigeault, com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malawi
Malawi, officially the Republic of Malawi, is a landlocked country in Southeastern Africa. It is bordered by Zambia to the west, Tanzania to the north and northeast, and Mozambique to the east, south, and southwest. Malawi spans over and has an estimated population of 21,240,689 (as of 2024). Lilongwe is its capital and largest city, while the next three largest cities are Blantyre, Mzuzu, and Zomba, the former capital. The part of Africa now known as Malawi was settled around the 10th century by the Akafula, also known as the Abathwa. Later, the Bantu groups came and drove out the Akafula and formed various kingdoms such as the Maravi and Nkhamanga kingdoms, among others that flourished from the 16th century. In 1891, the area was colonised by the British as the British Central African Protectorate, and it was renamed '' Nyasaland'' in 1907. In 1964, Nyasaland became an independent country as a Commonwealth realm under Prime Minister Hastings Banda, and was rena ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye (cyclone)
The eye is a region of mostly calm weather at the center of a tropical cyclone. The eye of a storm is a roughly circular area, typically in diameter. It is surrounded by the eyewall, a ring of towering thunderstorms where the most severe weather and highest winds of the cyclone occur. The cyclone's lowest barometric pressure occurs in the eye and can be as much as 15 percent lower than the pressure outside the storm. In strong tropical cyclones, the eye is characterized by light winds and clear skies, surrounded on all sides by a towering, symmetric eyewall. In weaker tropical cyclones, the eye is less well defined and can be covered by the central dense overcast, an area of high, thick clouds that show up brightly on satellite imagery. Weaker or disorganized storms may also feature an eyewall that does not completely encircle the eye or have an eye that features heavy rain. In all storms, however, the eye is where the barometer reading is lowest. Structure A typical tropi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tromelin Island
Tromelin Island (; , ), once called the Isle of Sand, is a low, flat island in the Indian Ocean about north of Réunion and about east of Madagascar. Both France and Mauritius claim sovereignty over the islands, and France includes it in the Scattered Islands in the Indian Ocean, the fifth district of the French Southern and Antarctic Lands. Tromelin has facilities for scientific expeditions and a weather station. It is a nesting site for birds and green sea turtles. Etymology The island is named in honour of Jacques Marie Boudin de Tromelin de La Nuguy, captain of the French corvette . He arrived at the island on 29 November 1776, and rescued eight stranded enslaved Malagasy language, Malagasy people who had been on the island for 15 years. Description Tromelin is situated in the Mascarene Basin and is part of the Scattered Islands in the Indian Ocean, Îles Éparses. It is currently only high. It formed as a volcano, now eroded, and developed an atoll ring of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convection (meteorology)
Atmospheric convection is the vertical transport of heat and moisture in the atmosphere. It occurs when warmer, less dense air rises, while cooler, denser air sinks. This process is driven by Air parcel, parcel-environment instability, meaning that a "parcel" of air is warmer and less dense than the surrounding environment at the same altitude. This difference in temperature and density (and sometimes humidity) causes the parcel to rise, a process known as buoyancy. This rising air, along with the compensating sinking air, leads to mixing, which in turn expands the height of the planetary boundary layer (PBL), the lowest part of the atmosphere directly influenced by the Earth's surface. This expansion contributes to increased Wind, winds, cumulus cloud development, and decreased surface Dew point, dew points (the temperature below which condensation occurs). Convection plays a crucial role in weather patterns, influencing cloud formation, wind, and the development of Thunderstor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wind Shear
Wind shear (; also written windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal wind shear. Vertical wind shear is a change in wind speed or direction with a change in altitude. Horizontal wind shear is a change in wind speed with a change in lateral position for a given altitude. Wind shear is a microscale meteorological phenomenon occurring over a very small distance, but it can be associated with mesoscale or synoptic scale weather features such as squall lines and cold fronts. It is commonly observed near microbursts and downbursts caused by thunderstorms, fronts, areas of locally higher low-level winds referred to as low-level jets, near mountains, radiation inversions that occur due to clear skies and calm winds, buildings, wind turbines, and sailboats. Wind shear has significant effects on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumatra
Sumatra () is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the list of islands by area, sixth-largest island in the world at 482,286.55 km2 (182,812 mi.2), including adjacent islands such as the Simeulue Island, Simeulue, Nias Island, Nias, Mentawai Islands, Mentawai, Enggano Island, Enggano, Riau Islands, Bangka Belitung and Krakatoa archipelago. Sumatra is an elongated landmass spanning a diagonal northwest–southeast axis. The Indian Ocean borders the northwest, west, and southwest coasts of Sumatra, with the island chain of Simeulue, Nias, Mentawai Islands, Mentawai, and Enggano off the western coast. In the northeast, the narrow Strait of Malacca separates the island from the Malay Peninsula, which is an extension of the Eurasian continent. In the southeast, the narrow Sunda Strait, containing the Krakatoa archipelago, separates Sumatra from Java. The northern tip of Sumatra is near ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low-pressure Area
In meteorology, a low-pressure area (LPA), low area or low is a region where the atmospheric pressure is lower than that of surrounding locations. It is the opposite of a high-pressure area. Low-pressure areas are commonly associated with inclement weather (such as cloudy, windy, with possible rain or storms), while high-pressure areas are associated with lighter winds and clear skies. Winds circle anti-clockwise around lows in the northern hemisphere, and clockwise in the southern hemisphere, due to opposing Coriolis forces. Low-pressure systems form under areas of wind divergence that occur in the upper levels of the atmosphere (aloft). The formation process of a low-pressure area is known as cyclogenesis. In meteorology, atmospheric divergence aloft occurs in two kinds of places: * The first is in the area on the east side of upper troughs, which form half of a Rossby wave within the Westerlies (a trough with large wavelength that extends through the troposphere). * A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intertropical Convergence Zone
The Intertropical Convergence Zone (ITCZ , 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 monsoon, monsoonal circulation, it is sometimes referred to as a ''monsoon trough'' (a usage that is more common in Australia and parts of Asia). Meteorology The ITCZ was originally identified from the 1920s to the 1940s as the ''Intertropical Front'' (''ITF''), but after the recognition in the 1940s and the 1950s of the significance of convergence zone, wind field convergence in tropics, tropical weather production, the term ''Intertropical Convergence Zone'' (''ITCZ'') was then applied. The ITCZ appears as a band of clouds, usually thunderstorms, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
