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Cyclone Harold
Severe Tropical Cyclone Harold was a very powerful tropical cyclone which caused widespread destruction in the Solomon Islands, Vanuatu, Fiji, and Tonga during April 2020. It was the first Tropical cyclone scales#Australia and Fiji, Category 5 tropical cyclone in 2020. The seventh named storm of the 2019–20 Australian region cyclone season, eighth named storm, and fourth severe tropical cyclone of the 2019–20 South Pacific cyclone season, Harold was first noted as a developing tropical low within a trough of low pressure during April 1, while it was located to the east of Papua New Guinea. Over the next day, the system moved south-eastwards over the Solomon Sea, before it was classified as a tropical cyclone and named Harold by the Australian Bureau of Meteorology. The system moved into the Fiji Meteorological Service, Fiji Meteorological Service's area of responsibility on April 2 and began to explosively intensify by April 3, reaching Category 4 status by April&nb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pentecost Island
Pentecost is one of the 83 islands that make up the Oceania, South Pacific nation of Vanuatu. It lies due north of capital Port Vila. Pentecost is known as in French language, French and in Bislama. The island was known in its native languages by names such as ''Vanu Aroaroa'', although these names are not in common use today. Pentecost has also been referred to as ''Raga'' or ''Araga'', a tribal name that originated in the north but is now widely applied to the whole island. In old sources, it is occasionally referred to as Whitsuntide Island. Geography Pentecost is a lush, mountainous island which stretches north to south over some . It has an area of . The mountain range, of which the highest is Mount Vulmat (), marks the dividing line between the humid, rainy eastern coast and the more temperate western coast. The coastal plains, cross-cut by small torrents, are generally very green and ideally suited for plantations and livestock. The climate on Pentecost is humid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Dollar
The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introduced the U.S. dollar at par with the Spanish dollar, Spanish silver dollar, divided it into 100 cent (currency), cents, and authorized the Mint (facility), minting of coins denominated in dollars and cents. U.S. banknotes are issued in the form of Federal Reserve Notes, popularly called greenbacks due to their predominantly green color. The U.S. dollar was originally defined under a bimetallism, bimetallic standard of (0.7734375 troy ounces) fine silver or, from Coinage Act of 1834, 1834, fine gold, or $20.67 per troy ounce. The Gold Standard Act of 1900 linked the dollar solely to gold. From 1934, its equivalence to gold was revised to $35 per troy ounce. In 1971 all links to gold were repealed. The U.S. dollar became an important intern ... [...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] |
Tropical Cyclone Basins
Traditionally, areas of tropical cyclone formation are divided into seven basins. These include the North Atlantic Ocean, the eastern and western parts of the North Pacific Ocean, the Southwest Pacific, the Southwest and Southeast Indian Oceans, and the North Indian Ocean (Arabian Sea and Bay of Bengal). The West Pacific is the most active and the north Indian the least active. An average of 86 tropical cyclones of tropical storm intensity form annually worldwide, with 47 reaching hurricane/typhoon strength, and 20 becoming intense tropical cyclones, super typhoons, or major hurricanes (at least of Category 3 intensity). __TOC__ Overview Northern Hemisphere North Atlantic Ocean This region includes the North Atlantic Ocean, the Caribbean Sea, and the Gulf of Mexico. Tropical cyclone formation here varies widely from year to year, ranging from one to over twenty-five per year. Most Atlantic tropical storms and hurricanes form between June 1 and November 30. The Unite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Joint Typhoon Warning Center
The Joint Typhoon Warning Center (JTWC) is a joint United States Navy – United States Air Force command in Pearl Harbor, Hawaii. The JTWC is responsible for the issuing of tropical cyclone warnings in the North-West Pacific Ocean, South Pacific Ocean, and Indian Ocean for all branches of the U.S. Department of Defense and other U.S. government agencies. Their warnings are intended primarily for the protection of U.S. military ships and aircraft, as well as military installations jointly operated with other countries around the world. Its U.S. Navy components are aligned with the Naval Meteorology and Oceanography Command. History The origins of the Joint Typhoon Warning Center (JTWC) can be traced back to June 1945, when the Fleet Weather Center/Typhoon Tracking Center was established on the island of Guam, after multiple typhoons, including Typhoon Cobra of December 1944 and Typhoon Connie in June 1945, had caused a significant loss of men and ships. At this time th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Honiara
Honiara () is the capital and largest city of Solomon Islands, situated on the northwestern coast of Guadalcanal. , it had a population of 92,344 people. The city is served by Honiara International Airport and the seaport of Point Cruz, and lies along the Kukum Highway. In 1983, a Capital districts and territories, capital territory – comprising the 22 square-kilometre metropolitan area of Honiara – was proclaimed, with a self-governing status akin to a Provinces of Solomon Islands, province, although the city also retained an older role as capital of Guadalcanal Province. The airport area to the east of Honiara was the site of a battle between the United States and the Japanese during the Guadalcanal Campaign in World War II, the Battle for Henderson Field of 1942, from which the former emerged victorious. After Honiara became the new administrative centre of the British Solomon Islands Protectorate in 1952 with the addition of many administrative buildings, the town began t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Tropical Cyclone Intensity Scale
Tropical cyclones are ranked on one of five tropical cyclone intensity scales, according to their maximum sustained winds and which tropical cyclone basins they are located in. Only a few classifications are used officially by the meteorological agencies monitoring the tropical cyclones, but other scales also exist, such as accumulated cyclone energy, the Power Dissipation Index, the Integrated Kinetic Energy Index, and the Hurricane Severity Index. Tropical cyclones that develop in the Northern Hemisphere are classified by the warning centres on one of three intensity scales. Tropical cyclones or subtropical cyclones that exist within the North Atlantic Ocean or the North-eastern Pacific Ocean are classified as either tropical depressions or tropical storms. Should a system intensify further and become a hurricane, then it will be classified on the Saffir–Simpson hurricane wind scale, and is based on the estimated maximum sustained winds over a 1-minute period. In the We ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cold-core Low
A cold-core low, also known as an upper level low or cold-core cyclone, is a cyclone aloft which has an associated cold pool of air residing at high altitude within the Earth's troposphere, without a frontal structure. It is a low pressure system that strengthens with height in accordance with the thermal wind relationship. If a weak surface circulation forms in response to such a feature at subtropical latitudes of the eastern north Pacific or north Indian oceans, it is called a subtropical cyclone. Cloud cover and rainfall mainly occurs with these systems during the day. Severe weather, such as tornadoes, can occur near the center of cold-core lows. Cold lows can help spawn cyclones with significant weather impacts, such as polar lows, and Kármán vortices. Cold lows can lead directly to the development of tropical cyclones, owing to their associated cold pool of air aloft or by acting as additional outflow channels to aid in further development. Characteristics Cold ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sea Surface Temperatures
Sea surface temperature (or ocean surface temperature) is the ocean temperature, temperature of ocean water close to the surface. The exact meaning of ''surface'' varies in the literature and in practice. It is usually between and below the sea surface. Sea surface temperatures greatly modify air masses in the Atmosphere of Earth, Earth's atmosphere within a short distance of the shore. The thermohaline circulation has a major impact on average sea surface temperature throughout most of the world's oceans. Warm sea surface temperatures can develop and Tropical cyclogenesis, strengthen cyclones over the ocean. Tropical cyclones can also cause a cool wake. This is due to turbulent mixing of the upper of the ocean. Sea surface temperature changes during the day. This is like the air above it, but to a lesser degree. There is less variation in sea surface temperature on breezy days than on calm days. Coastal sea surface temperatures can cause offshore winds to generate upwelling ... [...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] |
Outflow (meteorology)
Outflow, in meteorology, is air that flows outwards from a storm system. It is associated with ridging, or anticyclone, anticyclonic flow. In the low levels of the troposphere, outflow radiates from thunderstorms in the form of a wedge of rain-cooled air, which is visible as a thin rope-like cloud on weather satellite imagery or a fine line on weather radar imagery. For observers on the ground, a thunderstorm outflow boundary often approaches in otherwise clear skies as a low, thick cloud that brings with it a gust front. Low-level outflow boundaries can disrupt the center of small tropical cyclones. However, outflow aloft is essential for the strengthening of a tropical cyclone. If this outflow is restricted or undercut, the tropical cyclone weakens. If two tropical cyclones are close, the upper-level outflow from the upwind system can limit the development of the other system. Thunderstorms For thunderstorms, outflow tends to indicate the development of a system. Large quan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Convection
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 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 winds, cumulus cloud development, and decreased surface dew points (the temperature below which condensation occurs). Convection plays a crucial role in weather patterns, influencing cloud formation, wind, and the development of thunderstorms, which can be associa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
