Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Humboldt Current
The Humboldt Current, also called the Peru Current, is a cold, low-salinity ocean current that flows north along the western coast of South America. It is an eastern boundary current flowing in the direction of the equator, and extends 500–1,000 km (310–620 mi) offshore. The Humboldt Current is named after the Prussian naturalist Alexander von Humboldt. In 1846, von Humboldt reported measurements of the cold-water current in his book Cosmos. The current extends from southern Chile (~45th parallel south) to northern Peru (~4th parallel south) where cold, upwelled, waters intersect warm tropical waters to form the Equatorial Front. Sea surface temperatures off the coast of Peru, around 5th parallel south, reach temperatures as low as 16 °C (61 °F). This is highly uncharacteristic of tropical waters, as most other regions have temperatures measuring above 25 °C (77 °F). Upwelling brings nutrients to the surface, which support phytoplankton and ultimately increase biological productivity. The Humboldt Current is a highly productive ecosystem. It is the most productive eastern boundary current system. It accounts for roughly 18-20% of the total worldwide marine fish catch. The species are mostly pelagic: sardines, anchovies and jack mackerel. The system's high productivity supports other important fishery resources as well as marine mammals (eared seals and cetaceans) and seabirds. Periodically, the upwelling that drives the system's productivity is disrupted by the El Niño-Southern Oscillation (ENSO) event, often with large social and economic impacts. The Humboldt has a considerable cooling influence on the climate of Chile, Peru and Ecuador. It is also largely responsible for the aridity of Atacama Desert in northern Chile and coastal areas of Peru and also of the aridity of southern Ecuador. Marine air is cooled by the current and thus is not conducive to generating precipitation (although clouds and fog are produced).
  • 1.6K
  • 07 Oct 2022
Topic Review
Humid Continental Climate
A humid continental climate is a climatic region defined by Russo-German climatologist Wladimir Köppen in 1900, typified by four distinct seasons and large seasonal temperature differences, with warm to hot (and often humid) summers and cold (sometimes severely cold in the northern areas) winters. Precipitation is usually distributed throughout the year. The definition of this climate regarding temperature is as follows: the mean temperature of the coldest month must be below −3 °C (26.6 °F) and there must be at least four months whose mean temperatures are at or above 10 °C (50 °F). In addition, the location in question must not be semi-arid or arid. The Dfb, Dwb and Dsb subtypes are also known as hemiboreal. Humid continental climates are generally found roughly between latitudes 40° N and 60° N, within the central and northeastern portions of North America, Europe, and Asia. They are much less commonly found in the Southern Hemisphere due to the larger ocean area at that latitude and the consequent greater maritime moderation. In the Northern Hemisphere some of the humid continental climates, typically in Hokkaido, Northern Honshu, Sakhalin island, Scandinavia, Nova Scotia, and Newfoundland are heavily maritime-influenced, with relatively cool summers and winters being just below the freezing mark. More extreme humid continental climates found in northeast China , southern Siberia, the Canadian Prairies, and the Great Lakes region of the American Midwest and Central Canada combine hotter summer maxima and colder winters than the marine-based variety.
  • 6.5K
  • 29 Sep 2022
Topic Review
Humid Subtropical Climate
A humid subtropical climate is a zone of climate characterized by hot, humid summers, and cool to mild winters. These climates normally lie on the southeast side of all continents, generally between latitudes 25° and 35° and are located poleward from adjacent tropical climates. While many subtropical climates tend to be located at or near coastal locations, in some cases they extend inland, most notably in China and the United States , where they exhibit more pronounced seasonal variations and sharper contrasts between summer and winter, as part of a gradient between the more tropical climates of the southern coasts of these countries and the more continental climates of China and the United States ' northern and central regions (localities around the Ohio and Yangtze rivers exhibiting continental influence from the north, compared to climates around the Gulf of Mexico and the South China Sea, which exhibit tropical influence due to their southern coastal positions). The humid subtropical climate classification was officially created under the Trewartha Climate classification. Trewartha attempted to redefine middle latitude climates in the Koppen system since many climatologists argued that his "C" climate zone was too broad. Trewartha attempted to separate the middle latitude in three zones (subarctic, temperate, and subtropical). In this classification, climates are termed humid subtropical when they have at least 8 months with a mean temperature above 10 °C (50 °F). Under the Holdridge life zones classification, the subtropical climates have a biotemperature between the frost or critical temperature line, 16 to 18 °C (61 to 64 °F) (depending on locations in the world) and 24 °C (75 °F), and these climates are humid (or even perhumid or superhumid) when the potential evapotranspiration (PET) ratio (= PET / Precipitation) is less than 1. In the Holdridge classification, the humid subtropical climates coincide more or less with the warmest Cfa and Cwa climates and the less warm humid tropical "Köppen" climates (Aw, Am and Af). In a humid subtropical climate, summers are typically long, hot and humid. Monthly mean summer temperatures are normally between 24 and 27 °C (75 and 81 °F). A deep current of tropical air dominates the humid subtropics at the time of high sun, and daily intense (but brief) convective thundershowers are common. Summer high temperatures are typically in the high 20s to mid-30s °C (80s or 90s °F), while overnight lows in the summer are typically in the lower 20s °C (70s °F). Monthly mean temperatures in winter are often mild, typically averaging 7.5 to 16 °C (45.5 to 60.8 °F). Daytime highs in winter normally are in the 10 to 16 °C (50 to 61 °F) range, while overnight lows are from 2 to 7 °C (36 to 45 °F), though the poleward boundaries of this climate feature colder temperatures. Rainfall often shows a summer peak, especially where monsoons are well developed, as in Southeast Asia and South Asia. Other areas have a more uniform or varying rainfall cycles, but consistently lack any predictably dry summer months. Most summer rainfall occurs during thunderstorms that build up due to the intense surface heating and strong subtropical sun angle. Weak tropical lows that move in from adjacent warm tropical oceans, as well as infrequent tropical storms often contribute to summer seasonal rainfall peaks. Winter rainfall is often associated with large storms in the westerlies that have fronts that reach down into subtropical latitudes. However, many subtropical climates such as southeast Asia and Florida in the United States have very dry winters, with frequent brush fires and water shortages.
  • 4.7K
  • 01 Dec 2022
Topic Review
Humidification and Dehumidification Desalination
Humidification–dehumidification desalination (HDH) is described as a novel volume reduction method that employs a carrier gas for the thermal desalination of water. Currently used for small scale desalination, the advantages provided by the HDH method are too great to be ignored. The benefits of the process include the use of low-grade energy and simple design and construction.
  • 1.8K
  • 14 Jan 2022
Topic Review Video
Humipedon
The soil covers our entire planet and corresponds to the most superficial part of the earth's crust. Exposed to the attack of atmospheric agents and living organisms, the soil is organized in layers recognizable to the naked eye, more organic towards the atmosphere or water (if submerged), more mineral towards the rocky part of the bottom. To facilitate its study, specialists divided the soil into three sections: richer in organisms part -> 1. Humipedon; bottom still in contact with the unaltered rock section -> 3. Lithopedon; in-between, central, mineral part -> 2. Copedon. The present encyclopedia entry describes the variability of the humipedons of planet Earth. They have been subdivided in ecological groups and classified into different humus systems. The aim is to display them and diffuse their knowledge.
  • 1.1K
  • 30 Jul 2022
Topic Review
Hunga Tonga
Template:Infobox Island Hunga Tonga-Hunga Haʻapai is a volcanic island located about 30 kilometres (19 miles) south-southeast of Fonuafoʻou island in Tonga. The volcano is part of the highly active Tonga-Kermadec Islands volcanic arc, a subduction zone extending from New Zealand north-northeast to Fiji. It lies about 100 kilometres (62 mi) above a very active seismic zone. The island arc is formed at the convergent boundary where the Pacific Plate subducts under the Indo-Australian Plate.
  • 1.6K
  • 24 Oct 2022
Topic Review
Hurdles in Struggle against Nanoplastic Pollution
Plastics are considered one of the most serious environmental global concerns as they are ubiquitous and contribute to the build-up of pollution. Nanoplastics are also an emerging environmental concern as little is known about their generation, degradation, transformation, ageing, and transportation. Owing to their small size, nanoplastics can be trapped by filter-feeding organisms and can enter the food chain at an early stage. 
  • 521
  • 29 Oct 2021
Topic Review
Hurricane Preparedness
Cyclone mitigation encompasses the actions and planning taken before a tropical cyclone strikes to mitigate damage and injury from the storm. Knowledge of tropical cyclone impacts on an area help plan for future possibilities. Preparedness may involve preparations made by individuals as well as centralized efforts by governments or other organizations. Tracking storms during the tropical cyclone season helps individuals know current threats. Regional Specialized Meteorological Centers and Tropical Cyclone Warning Centers provide current information and forecasts to help individuals make the best decision possible.
  • 340
  • 28 Oct 2022
Topic Review
Hybrid Artificial Intelligence in Groundwater
As one of the world’s most valuable and vital water sources, groundwater is integral to many facets of human life, including food production, economic growth, and safe drinking water. Developing precise soft computing methods for groundwater management, which includes quality and quantity, is crucial for improving water resources planning and management. Significant progress has been made in groundwater management using hybrid machine learning (ML) models as artificial intelligence (AI). 
  • 485
  • 12 May 2023
Topic Review
Hybrid Solar Dryers
Hybrid solar dryers, by definition, designed and constructed using direct solar energy and a heat exchanger. The products are dried under direct solar radiation and/or backup energy or stored heat when sunlight is not available. These types of dryers are used in single and mixed modes of drying. Several studies have been developed to test different techniques to improve solar dryers, considering the possible use of thermal storage materials, the deep bed drying method, improved solar collector designs and energy hybridization. They can be divided several ways, depending on their construction.
  • 462
  • 17 Jan 2024
  • Page
  • of
  • 271
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback