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Sumatra Squall Lines
A Sumatra squall (plural: Sumatra squalls or Sumatras) is a squall line—a line of thunderstorms—that develops over the Indonesian island of Sumatra and moves eastwards over the Straits of Malacca, producing heavy rain and gusty winds in Malaysia and Singapore. Sumatra squalls typically form in the predawn hours and early morning, and last for a few hours. They may occur at any time of the year, but are most common from April to November, coinciding with the southwest monsoon and inter-monsoon periods when the prevailing winds have a greater westerly component. The passage of Sumatra squalls can result in fallen trees, flash floods, and property damage. Shipping along the Straits of Malacca may also be affected. Effects Typically, Sumatra squalls affect Malaysia and Singapore for one to two hours in the night or morning, producing heavy rains along with wind gusts of . The highest recorded wind gust in Singapore— on 25 April 1984, in Tengah—was produced by a Sumatra squall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sumatra Squall 2022-07-29
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 473,481 km2 (182,812 mi.2), not 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] |
Weather Model
Numerical weather prediction (NWP) uses mathematical models of the atmosphere and oceans to predict the weather based on current weather conditions. Though first attempted in the 1920s, it was not until the advent of computer simulation in the 1950s that numerical weather predictions produced realistic results. A number of global and regional forecast models are run in different countries worldwide, using current weather observations relayed from radiosondes, weather satellites and other observing systems as inputs. Mathematical models based on the same physical principles can be used to generate either short-term weather forecasts or longer-term climate predictions; the latter are widely applied for understanding and projecting climate change. The improvements made to regional models have allowed for significant improvements in tropical cyclone track and air quality forecasts; however, atmospheric models perform poorly at handling processes that occur in a relatively const ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Barisan Mountains
The Bukit Barisan or the Barisan Mountains are a mountain range on the western side of Sumatra, Indonesia, covering nearly 1,700 km (1,050 mi) from the north to the south of the island. The Bukit Barisan range consists primarily of volcanoes shrouded in dense jungle cover, including Sumatran tropical pine forests on the higher slopes. The highest peak of the range is Mount Kerinci at 3,800 metres (12,467 ft). The Bukit Barisan Selatan National Park is situated towards the southern end of the range Liwa, Indonesia. The name Bukit Barisan actually means "row of hills" or "hills that make a row" in Malay, for the range stretches end to end along the island of Sumatra. There are 35 active volcanoes in Bukit Barisan. The largest volcano is the supervolcano Toba within the 100 km (62 miles) × 30 km (19 miles) Lake Toba, which was created after a caldera collapse (est. in 74,000 Before Present). The eruption is estimated to have been at level eight ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mountain Waves
In meteorology, lee waves are atmospheric stationary waves. The most common form is mountain waves, which are atmospheric internal gravity waves. These were discovered in 1933 by two German glider pilots, Hans Deutschmann and Wolf Hirth, above the Krkonoše. They are periodic changes of atmospheric pressure, temperature and orthometric height in a current of air caused by vertical displacement, for example orographic lift when the wind blows over a mountain or mountain range. They can also be caused by the surface wind blowing over an escarpment or plateau, or even by upper winds deflected over a thermal updraft or cloud street. The vertical motion forces periodic changes in speed and direction of the air within this air current. They always occur in groups on the lee side of the terrain that triggers them. Sometimes, mountain waves can help to enhance precipitation amounts downwind of mountain ranges. Usually a turbulent vortex, with its axis of rotation parallel to the moun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peninsular Malaysia
Peninsular Malaysia ( ms, Semenanjung Malaysia; Jawi: سمننجڠ مليسيا), or the States of Malaya ( ms, Negeri-negeri Tanah Melayu; Jawi: نڬري-نڬري تانه ملايو), also known as West Malaysia or the Malaysian Peninsula, is the part of Malaysia that occupies the southern half of the Malay Peninsula in Southeast Asia and the nearby islands. Its area totals , which is nearly 40% of the total area of the country; the other 60% is in East Malaysia. For comparison, it is slightly larger than England (130,395 km2). It shares a land border with Thailand to the north and a maritime border with Singapore to the south. Across the Strait of Malacca to the west lies the island of Sumatra, and across the South China Sea to the east lie the Natuna Islands of Indonesia. At its southern tip, across the Strait of Johor, lies the island country of Singapore. Peninsular Malaysia accounts for the majority (roughly 81.3%) of Malaysia's population and economy; as of 2017, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Land Breeze
A sea breeze or onshore breeze is any wind that blows from a large body of water toward or onto a landmass; it develops due to differences in air pressure created by the differing heat capacities of water and dry land. As such, sea breezes are more localised than prevailing winds. Because land heats up much faster than water under solar radiation, a sea breeze is a common occurrence along coasts after sunrise. By contrast, a land breeze or offshore breeze is the reverse effect: dry land also cools more quickly than water and, after sunset, a sea breeze dissipates and the wind instead flows from the land towards the sea. Sea breezes and land breezes are both important factors in coastal regions' prevailing winds. The term offshore wind may refer to any wind over open water. Wind farms are often situated near a coast to take advantage of the normal daily fluctuations of wind speed resulting from sea or land breezes. While many onshore wind farms and offshore wind farms do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergence Zone
A convergence zone in meteorology is a region in the atmosphere where two prevailing flows meet and interact, usually resulting in distinctive weather conditions. This causes a mass accumulation that eventually leads to a vertical movement and to the formation of clouds and precipitation. Large-scale convergence, called synoptic-scale convergence, is associated with weather systems such as baroclinic troughs, low-pressure areas, and cyclones. The large-scale convergence zone formed over the equator, the Intertropical Convergence Zone, has condensed and intensified as a result of the global increase in temperature. Small-scale convergence will give phenomena from isolated cumulus clouds to large areas of thunderstorms. The inverse of convergence is divergence. Large scale An example of a convergence zone is the Intertropical Convergence Zone (ITCZ), a low pressure area which girdles the Earth at the Equator.Waliser, D.E.; Jiang, X. (2015). "Tropical Meteorology and Climate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ligne De Grain
The ''ligne'' ( ), or line or Paris line, is a historic unit of length used in France and elsewhere prior to the adoption of the metric system in the late 18th century, and used in various sciences after that time. The ''loi du 19 frimaire an VIII'' (Law of 10 December 1799) states that one metre is equal to exactly 443.296 French lines. It is vestigially retained today by French and Swiss watchmakers to measure the size of watch casings, in button making and in ribbon manufacture. Current use Watchmaking There are 12 ''lignes'' to one French inch (''pouce''). The standardized conversion for a ligne is 2.2558291 mm (1 mm = 0.443296 ''ligne''), and it is abbreviated with the letter L or represented by the triple prime, . One ligne is the equivalent of 0.0888 international inch. This is comparable in size to the British measurement called "line" (one-twelfth of an English inch), used prior to 1824. (The French inch at that time was slightly larger than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South China Sea
The South China Sea is a marginal sea of the Western Pacific Ocean. It is bounded in the north by the shores of South China (hence the name), in the west by the Indochinese Peninsula, in the east by the islands of Taiwan and northwestern Philippines (mainly Luzon, Mindoro and Palawan), and in the south by Borneo, eastern Sumatra and the Bangka Belitung Islands, encompassing an area of around . It communicates with the East China Sea via the Taiwan Strait, the Philippine Sea via the Luzon Strait, the Sulu Sea via the straits around Palawan (e.g. the Mindoro and Balabac Straits), the Strait of Malacca via the Singapore Strait, and the Java Sea via the Karimata and Bangka Straits. The Gulf of Thailand and the Gulf of Tonkin are also part of the South China Sea. The shallow waters south of the Riau Islands are also known as the Natuna Sea. The South China Sea is a region of tremendous economic and geostrategic importance. One-third of the world's maritime shipping passe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropical Cyclone
A tropical cyclone is a rapidly rotating storm system characterized by a low-pressure center, a closed low-level atmospheric circulation, strong winds, and a spiral arrangement of thunderstorms that produce heavy rain and squalls. Depending on its location and strength, a tropical cyclone is referred to by different names, including hurricane (), typhoon (), tropical storm, cyclonic storm, tropical depression, or simply cyclone. A hurricane is a strong tropical cyclone that occurs in the Atlantic Ocean or northeastern Pacific Ocean, and a typhoon occurs in the northwestern Pacific Ocean. In the Indian Ocean, South Pacific, or (rarely) South Atlantic, comparable storms are referred to simply as "tropical cyclones", and such storms in the Indian Ocean can also be called "severe cyclonic storms". "Tropical" refers to the geographical origin of these systems, which form almost exclusively over tropical seas. "Cyclone" refers to their winds moving in a circle, whirling round ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Madden–Julian Oscillation
The Madden–Julian oscillation (MJO) is the largest element of the intraseasonal (30- to 90-day) variability in the tropical atmosphere. It was discovered in 1971 by Roland Madden and Paul Julian of the American National Center for Atmospheric Research (NCAR). It is a large-scale coupling between atmospheric circulation and tropical deep atmospheric convection. Unlike a standing pattern like the El Niño–Southern Oscillation (ENSO), the Madden–Julian oscillation is a traveling pattern that propagates eastward, at approximately , through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself most clearly as anomalous rainfall. The Madden–Julian oscillation is characterized by an eastward progression of large regions of both enhanced and suppressed tropical rainfall, observed mainly over the Indian and Pacific Ocean. The anomalous rainfall is usually first evident over the western Indian Ocean, and remains evi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
La Niña
La Niña (; ) is an oceanic and atmospheric phenomenon that is the colder counterpart of as part of the broader El Niño–Southern Oscillation (ENSO) climate pattern. The name ''La Niña'' originates from Spanish for "the girl", by analogy to ''El Niño'', meaning "the boy". In the past, it was also called an ''anti-El Niño'' and ''El Viejo'', meaning "the old man." During a La Niña period, the sea surface temperature across the eastern equatorial part of the central Pacific Ocean will be lower than normal by 3–5 °C (5.4–9 °F). An appearance of La Niña often persists for longer than five months. El Niño and La Niña can be indicators of weather changes across the globe. Atlantic and Pacific hurricanes can have different characteristics due to lower or higher wind shear and cooler or warmer sea surface temperatures. Background ImageSize = width:800 height:70 PlotArea = left:50 bottom:20 width:700 height:40 Period = from:1900 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
