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Snow
Snow consists of individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout its life cycle, starting when, under suitable conditions, the ice crystals form in the atmosphere, increase to millimeter size, precipitate and accumulate on surfaces, then metamorphose in place, and ultimately melt, slide, or sublimate away. Snowstorms organize and develop by feeding on sources of atmospheric moisture and cold air. Snowflakes nucleate around particles in the atmosphere by attracting supercooled water droplets, which freeze in hexagonal-shaped crystals. Snowflakes take on a variety of shapes, basic among these are platelets, needles, columns, and rime. As snow accumulates into a snowpack, it may blow into drifts. Over time, accumulated snow metamorphoses, by sintering, sublimation, and freeze-thaw. Where the clima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extratropical Cyclone
Extratropical cyclones, sometimes called mid-latitude cyclones or wave cyclones, are low-pressure areas which, along with the anticyclones of high-pressure areas, drive the weather over much of the Earth. Extratropical cyclones are capable of producing anything from cloudiness and mild rain, showers to severe hail, thunderstorms, blizzards, and tornadoes. These types of cyclones are defined as Synoptic scale meteorology, large scale (synoptic) Low-pressure area, low pressure weather systems that occur in the middle latitudes of the Earth. In contrast with tropical cyclones, extratropical cyclones produce rapid changes in temperature and dew point along broad lines, called weather fronts, about the center of the cyclone. Terminology The term "cyclone" applies to numerous types of low pressure areas, one of which is the extratropical cyclone. The descriptor ''extratropical'' signifies that this type of cyclone generally occurs outside the tropics and in the middle latitudes of Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowflake
A snowflake is a single ice crystal that is large enough to fall through the Earth's atmosphere as snow.Knight, C.; Knight, N. (1973). Snow crystals. Scientific American, vol. 228, no. 1, pp. 100–107.Hobbs, P.V. 1974. Ice Physics. Oxford: Clarendon Press. Snow appears white in color despite being made of clear ice. This is because the many small crystal facets of the snowflakes scatter the sunlight between them. Each flake begins by forming around a tiny particle, called its nucleus, accumulating water droplets, which freeze and slowly form a crystal. Complex shapes emerge as the flake moves through differing temperature and humidity zones in the atmosphere, and possibly combines with other snowflakes. Because of this, snowflakes tend to look very different from one another. However, they may be categorized in eight broad classifications and at least 80 individual variants. The main constituent shapes for ice crystals, from which combinations may occur, are ''needle'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moisture
Moisture is the presence of a liquid, especially water, often in trace amounts. Moisture is defined as water in the adsorbed or absorbed phase. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapor present in the air. The soil also includes moisture. Moisture control in products Control of moisture in products can be a vital part of the process of the product. There is a substantial amount of moisture in what seems to be dry matter. Ranging in products from cornflake cereals to laundry detergent, washing powders, moisture can play an important role in the final quality of the product. There are two main aspects of concern in moisture control in products: allowing too much moisture or too little of it. For example, adding some water to cornflake cereal, which is sold by weight, reduces costs and prevents it from tasting too dry, but adding too much water can affect th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cloud
In meteorology, a cloud is an aerosol consisting of a visible mass of miniature liquid droplets, frozen crystals, or other particles, suspended in the atmosphere of a planetary body or similar space. Water or various other chemicals may compose the droplets and crystals. On Earth, clouds are formed as a result of saturation of the air when it is cooled to its dew point, or when it gains sufficient moisture (usually in the form of water vapor) from an adjacent source to raise the dew point to the ambient temperature. Clouds are seen in the Earth's homosphere, which includes the troposphere, stratosphere, and mesosphere. Nephology is the science of clouds, which is undertaken in the cloud physics branch of meteorology. The World Meteorological Organization uses two methods of naming clouds in their respective layers of the homosphere, Latin and common name. Genus types in the troposphere, the atmospheric layer closest to Earth's surface, have Latin names because of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Countries Receiving Snowfall
A country is a distinct part of the Earth, world, such as a state (polity), state, nation, or other polity, political entity. When referring to a specific polity, the term "country" may refer to a sovereign state, List of states with limited recognition, state with limited recognition, Country (other)#Administrative divisions, constituent country, or dependent territory. Most sovereign states, but not all countries, are members of the United Nations. There is no universal agreement on List of sovereign states, the number of "countries" in the world, since several states have disputed sovereignty status or limited recognition, and a number of non-sovereign entities are commonly considered countries. The definition and usage of the word "country" are flexible and have changed over time. ''The Economist'' wrote in 2010 that "any attempt to find a clear definition of a country soon runs into a thicket of exceptions and anomalies." Areas much smaller than a political entit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecosystem
An ecosystem (or ecological system) is a system formed by Organism, organisms in interaction with their Biophysical environment, environment. The Biotic material, biotic and abiotic components are linked together through nutrient cycles and energy flows. Ecosystems are controlled by external and internal Environmental factor, factors. External factors—including climate—control the ecosystem's structure, but are not influenced by it. By contrast, internal factors control and are controlled by ecosystem processes; these include decomposition, the types of species present, root competition, shading, disturbance, and succession. While external factors generally determine which Resource (biology), resource inputs an ecosystem has, their availability within the ecosystem is controlled by internal factors. Ecosystems are wikt:dynamic, dynamic, subject to periodic disturbances and always in the process of recovering from past disturbances. The tendency of an ecosystem to remain clo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Warfare
War is an armed conflict between the armed forces of State (polity), states, or between governmental forces and armed groups that are organized under a certain command structure and have the capacity to sustain military operations, or between such organized groups. It is generally characterized by widespread violence, destruction, and mortality, using Regular army, regular or Irregular military, irregular Military, military forces. ''Warfare'' refers to the common activities and characteristics of types of war, or of wars in general. Total war is warfare that is not restricted to purely legitimate military targets, and can result in massive Civilian casualty, civilian or other non-combatant suffering and Casualty (person), casualties. Etymology The English word ''war'' derives from the 11th-century Old English words and , from Old French ( as in modern French), in turn from the Frankish language, Frankish , ultimately deriving from the Proto-Germanic language, Proto-Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowmobile
A snowmobile, also known as a snowmachine (chiefly Alaskan), motor sled (chiefly Canadian), motor sledge, skimobile, snow scooter, or simply a sled is a motorized vehicle designed for winter travel and recreation on snow. Their engines normally drive a continuous track at the rear, while skis at the front provide directional control. The earliest snowmobiles were powered by readily available industrial four-stroke, air-cooled engines. These would quickly be replaced by lighter and more powerful two-stroke gasoline internal combustion engines and since the mid-2000s four-stroke engines had re-entered the market. The challenges of cross-country transportation in the winter led to the invention of an all-terrain vehicle specifically designed for travel across deep snow where other vehicles foundered. , the snowmobile market has been shared between the four large North American makers (Bombardier Recreational Products (BRP), Arctic Cat, Yamaha, and Polaris) and some specialized m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowboarding
Snowboarding is a recreational and competitive activity that involves descending a snow-covered surface while standing on a snowboard that is almost always attached to a rider's feet. It features in the Winter Olympic Games and Winter Paralympic Games. Snowboarding was developed in the United States, inspired by skateboarding, sledding, surfing, and skiing. It became popular around the world and was introduced as a Winter Olympic Sport at Nagano in 1998 and featured in the Winter Paralympics at Sochi in 2014. , its popularity (as measured by equipment sales) in the United States peaked in 2007 and has been in a decline since. History The first snowboards were developed in 1965 when Sherm Poppen, an engineer in Muskegon, Michigan, invented a toy for his daughters by fastening two skis together and attaching a rope to one end so he would have some control as they stood on the board and glided downhill. Dubbed the "snurfer" (combining snow and surfer) by his wife Nancy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skiing
Skiing is the use of skis to glide on snow for basic transport, a recreational activity, or a competitive winter sport. Many types of competitive skiing events are recognized by the International Olympic Committee (IOC), and the International Ski and Snowboard Federation (FIS). History Skiing has a history of almost five millennia. Although modern skiing has evolved from beginnings in Scandinavia, it may have been practiced more than 100 centuries ago in the Altai Mountains, according to an interpretation of ancient paintings. However, this continues to be debated. The word "ski" comes from the Old Norse word "skíð" which means to "split piece of wood or firewood". Asymmetrical skis were used in northern Finland and Sweden until at least the late 19th century. On one foot, the skier wore a long straight non-arching ski for sliding, and a shorter ski was worn on the other foot for kicking. The underside of the short ski was either plain or covered with animal skin to aid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
