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1991–92 South-West Indian Ocean Cyclone Season
The 1991–92 South-West Indian Ocean cyclone season was an average cyclone season in which most storms remained over open waters. At the time, the season's official bounds lasted from November 15, 1991, to April 30, 1992, although this season began early when three tropical depressions formed before the official start. The second, designated Tropical Depression A2 by the Météo-France office (MFR) on Réunion, passed north of Madagascar on October 16 before weakening. The first named storm was Severe Tropical Storm Alexandra, which developed on December 18 from the monsoon trough; many other storms during the year originated in this manner. Tropical Storm Bryna was the only tropical storm of the season to make landfall, having struck northeastern Madagascar on January 2. The basin was most active in February, when five named storms developed, including Tropical Depression Elizabetha which struck western Madagascar. In early March, Cyclone Harriet entered the b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1989–90 South-West Indian Ocean Cyclone Season
The 1989–90 South-West Indian Ocean cyclone season was an average cyclone season, with nine named storms and five tropical cyclones – a storm attaining maximum sustained winds of at least . The season officially ran from November 1, 1989, to April 30, 1990. Storms were officially tracked by the Météo-France office (MFR) on Réunion while the Joint Typhoon Warning Center (JTWC) in an unofficial basis. The first storm, Cyclone Alibera, was the second longest-lasting tropical cyclone on record in the basin, with a duration of 22 days. Alibera meandered and changed directions several times before striking southeastern Madagascar on January 1, 1989, where it was considered the worst storm since 1925. The cyclone killed 46 people and left widespread damage. Only the final storm of the year – Severe Tropical Storm Ikonjo – also had significant impact on land, when it left $1.5 million in damage (1990 USD) in the Seychelles. Of the remaining storms, se ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
El Niño
El Niño (; ; ) is the warm phase of the El Niño–Southern Oscillation (ENSO) and is associated with a band of warm ocean water that develops in the central and east-central equatorial Pacific (approximately between the International Date Line and 120°W), including the area off the Pacific coast of South America. The ENSO is the cycle of warm and cold sea surface temperature (SST) of the tropical central and eastern Pacific Ocean. El Niño is accompanied by high air pressure in the western Pacific and low air pressure in the eastern Pacific. El Niño phases are known to last close to four years; however, records demonstrate that the cycles have lasted between two and seven years. During the development of El Niño, rainfall develops between September–November. The cool phase of ENSO is es, La Niña, translation=The Girl, with SSTs in the eastern Pacific below average, and air pressure high in the eastern Pacific and low in the western Pacific. The ENSO cycle, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subtropical Cyclone
A subtropical cyclone is a weather system that has some characteristics of both tropical and an extratropical cyclone. As early as the 1950s, meteorologists were uncertain whether they should be characterized as tropical or extratropical cyclones. They were officially recognized and titled by the National Hurricane Center in 1972. Beginning in 2002, subtropical cyclones received names from the official tropical cyclone lists in the North Atlantic, South-west Indian Ocean, and South Atlantic basins. There are two definitions currently used for subtropical cyclones depending on their location. Across the north Atlantic and southwest Indian Ocean, they require some central convection fairly near the center surrounding a warming core existing in the mid-levels of the troposphere. Across the eastern half of the northern Pacific however, they require a mid-tropospheric cyclone to be cut off from the main belt of the westerlies and with only a weak surface circulation. Subtropical cyc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Melaky
Melaky is a region in northwestern Madagascar. It borders Boeny Region in northeast, Betsiboka in east, Bongolava in southeast and Menabe in south. The capital of the region is Maintirano. The population was estimated to be 309,805 in 2018 within the area of . Melaky has the smallest population and the smallest population density of all Malagasy regions. Administrative divisions Melaky Region is divided into five districts, which are sub-divided into 32 communes. * Ambatomainty District Ambatomainty is a district A district is a type of administrative division that, in some countries, is managed by the local government. Across the world, areas known as "districts" vary greatly in size, spanning regions or counties, several ... - 5 communes * Antsalova District - 5 communes * Besalampy District - 6 communes * Maintirano District - 14 communes * Morafenobe District - 4 communes Transport Airports *Ambatomainty Airport *Antsalova Airport *Besalampy Airport *Maintirano Airp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sava Region
Sava is a region in northern Madagascar. Its capital is Sambava. Until 2009 Sava belonged to Antsiranana Province. The region is situated at the northern part of the east coast of Madagascar. It is bordered by the region Diana to the north, Sofia to the west, and Analanjirofo to the south. As of 2018, its population was 1,123,013 and the total area is . The region contains wild areas such as Marojejy National Park. The name of the region is composed of the initial letters of its four principal towns: Sambava, Antalaha, Iharana (Vohimaro), and Andapa. Each of these towns claims itself the World Capital of Vanilla, a spice of which the region is the largest producer of in the world (especially the highly sought-after Bourbon vanilla variety). The economic importance of vanilla cultivation in the Sava Region encouraged the reconstruction of the road that connects the towns, called the ''Route de la vanille'' (The Vanilla Route), in the latter half of 2005. However, due to the vola ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coordinated Universal Time
Coordinated Universal Time or UTC is the primary time standard by which the world regulates clocks and time. It is within about one second of mean solar time (such as UT1) at 0° longitude (at the IERS Reference Meridian as the currently used prime meridian) and is not adjusted for daylight saving time. It is effectively a successor to Greenwich Mean Time (GMT). The coordination of time and frequency transmissions around the world began on 1 January 1960. UTC was first officially adopted as CCIR Recommendation 374, ''Standard-Frequency and Time-Signal Emissions'', in 1963, but the official abbreviation of UTC and the official English name of Coordinated Universal Time (along with the French equivalent) were not adopted until 1967. The system has been adjusted several times, including a brief period during which the time-coordination radio signals broadcast both UTC and "Stepped Atomic Time (SAT)" before a new UTC was adopted in 1970 and implemented in 1972. This change also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauritius
Mauritius ( ; french: Maurice, link=no ; mfe, label= Mauritian Creole, Moris ), officially the Republic of Mauritius, is an island nation in the Indian Ocean about off the southeast coast of the African continent, east of Madagascar. It includes the main island (also called Mauritius), as well as Rodrigues, Agaléga and St. Brandon. The islands of Mauritius and Rodrigues, along with nearby Réunion (a French overseas department), are part of the Mascarene Islands. The main island of Mauritius, where most of the population is concentrated, hosts the capital and largest city, Port Louis. The country spans and has an exclusive economic zone covering . Arab sailors were the first to discover the uninhabited island, around 975, and they called it ''Dina Arobi''. The earliest discovery was in 1507 by Portuguese sailors, who otherwise took little interest in the islands. The Dutch took possession in 1598, establishing a succession of short-lived settlements over a peri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. Origin of the term A likely and documented explanation is that the term is derived from the "dead horse" ritual of seamen (see Beating a dead horse). In this practice, the seaman paraded a straw-stuffed effigy of a horse around the deck before throwing it overboard. Seamen were paid partly in advance before a long voyage, and they frequently spent their pay all at once, resulting in a period of time without income. If they got advances from the ship's paymaster, they would incur debt. This period was called the "dead horse" time, and it usually lasted a month or two. The seaman's ceremony was to celebrate having worked off the "dead horse" debt. As west-bound shipping from Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maximum Sustained Wind
The maximum sustained wind associated with a tropical cyclone is a common indicator of the intensity of the storm. Within a mature tropical cyclone, it is found within the eyewall at a distance defined as the radius of maximum wind, or RMW. Unlike gusts, the value of these winds are determined via their sampling and averaging the sampled results over a period of time. Wind measuring has been standardized globally to reflect the winds at above the Earth's surface, and the maximum sustained wind represents the highest average wind over either a one-minute (US) or ten-minute time span (see the definition, below), anywhere within the tropical cyclone. Surface winds are highly variable due to friction between the atmosphere and the Earth's surface, as well as near hills and mountains over land. Over the ocean, satellite imagery determines the value of the maximum sustained winds within a tropical cyclone. Land, ship, aircraft reconnaissance observations, and radar imagery can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflow (meteorology)
Inflow is the flow of a fluid into a large collection of that fluid. Within meteorology, inflow normally refers to the influx of warmth and moisture from air within the Earth's atmosphere into storm systems. Extratropical cyclones are fed by inflow focused along their cold front and warm fronts. Tropical cyclones require a large inflow of warmth and moisture from warm oceans in order to develop significantly, mainly within the lowest of the atmosphere. Once the flow of warm and moist air is cut off from thunderstorms and their associated tornadoes, normally by the thunderstorm's own rain-cooled outflow boundary, the storms begin to dissipate. Rear-inflow jet, Rear inflow jets behind squall lines act to erode the broad precipitation (meteorology), rain shield behind the squall line, and accelerate its forward motion. Thunderstorms The inflow into a thunderstorm, or complex of thunderstorms, is the circulation of warm and humid air ahead of a trigger convergence zone such as a c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye (cyclone)
The eye is a region of mostly calm weather at the center of tropical cyclones. 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 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 the location of the storm's minimum barometric pressure—where the atmospheric p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trough (meteorology)
A trough is an elongated region of relatively low atmospheric pressure without a closed isobaric contour that would define it as a low pressure area. Since low pressure implies a low height on a pressure surface, troughs and ridges refer to features in an identical sense as those on a topographic map. Troughs may be at the surface, or aloft. Near-surface troughs sometimes mark a weather front associated with clouds, showers, and a wind direction shift. Upper-level troughs in the jet stream (as shown in diagram) reflect cyclonic filaments of vorticity. Their motion induces upper-level wind divergence, lifting and cooling the air ahead (downstream) of the trough and helping to produce cloudy and rain conditions there. Unlike fronts, there is not a universal symbol for a trough on a surface weather analysis chart. The weather charts in some countries or regions mark troughs by a line. In the United States, a trough may be marked as a dashed line or bold line. In the UK, Hon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
