South Bay, Los Angeles
The South Bay is a region of the Los Angeles metropolitan area, located in the southwest corner of Los Angeles County. The name stems from its geographic location stretching along the southern shore of Santa Monica Bay; the South Bay contains fifteen cities plus portions of the City of Los Angeles and unincorporated portions of the county. The area is bounded by the Pacific Ocean on the south and west and by the City of Los Angeles on the north and east; the South Bay includes: The Beach Cities El Segundo Manhattan Beach Hermosa Beach Redondo Beach Torrance The Palos Verdes Peninsula Palos Verdes Estates Rolling Hills Rolling Hills Estates Rancho Palos Verdes The southernmost neighborhoods of the City of Los Angeles Harbor City Harbor Gateway San Pedro Wilmington Inland cities of the South Bay Inglewood Hawthorne Gardena Lawndale Lomita Carson And unincorporated areas of L. A. County including: Lennox Del Aire And other small unincorporated "county strip" areas of Los Angeles County; the region is bordered on the north by LAX, on the northeast by the South Los Angeles region, on the east by the Gateway Cities, on the southeast by Long Beach.
The Harbor, San Diego and Century Freeways provide the region with its principal transportation links. The Los Angeles MTA's Blue Line is a light rail line running between Downtown Los Angeles and Downtown Long Beach, it is the first of the MTA's modern rail lines since the 1961 demise of the Pacific Electric Railway's Red Car system. The Green Line, a freeway-median light rail line serves the South Bay, it runs between Redondo Beach and Norwalk in the median of the Century Freeway, providing indirect access to Los Angeles International Airport via a shuttle bus and future automated people mover. Several ports and harbors in the South Bay provide access to Santa Catalina Island, a popular resort. In addition, Los Angeles International Airport borders El Segundo to the north in the neighborhood of Westchester, Los Angeles; the South Bay is one of the most culturally and ethnically diverse areas in the United States, with a even distribution of the population across African, Asian/Pacific Islander, European and Latino ancestry.
However, the racial and economic makeup varies across the region. El Segundo, Hermosa Beach, Redondo Beach and Torrance have a mixture of middle-to-upper class residents, of which are White American and Asian American; the Palos Verdes Peninsula and Manhattan Beach are two of the wealthiest communities in the United States, with some of the most expensive real estate in the United States. The city of Carson has large populations of African Americans. Hawthorne, Inglewood and Lawndale are diverse communities with pluralities of blacks and White Americans. Gardena is home to one of America's oldest Japanese communities. In addition, San Pedro has a large community of Croatian immigrants; the Port of Los Angeles, sprawling across the shorelines of San Pedro and Wilmington, is the busiest in the United States. When combined with the Port of Long Beach, it is the fifth-busiest in the world. Traditionally, most of the populations of Wilmington and San Pedro have worked for the port in some capacity, it is the primary driver of the Southern California economy: industrial growth in the Inland Empire is entirely attributable to increased port traffic since the 1980s.
The massive increase in cargo volume has created significant air pollution in neighboring communities. The South Bay is the traditional home of Southern California's aerospace industry. While shrunken from its Cold War peak, it still represents a major economic force, employing thousands in high-skill, high-wage engineering positions and generating enormous amounts of tax revenue. Northrop Grumman has a major facility in El Segundo where the F/A-18 Hornet fuselage is manufactured, as well as the headquarters of the Space Technology division in Redondo Beach and a facility at the Hawthorne Municipal Airport. Alcoa Fastening Systems, a subsidiary of Alcoa Inc. which produces aerospace fasteners, has their corporate headquarters located in Torrance with manufacturing facilities in both Torrance and Carson. Boeing and Lockheed Martin maintain extensive production facilities throughout the South Bay, Raytheon's Space and Airborne Systems business unit is based in El Segundo; the Los Angeles Air Force Base, in El Segundo, is the locus of much of this aerospace research activity, as it is the primary development facility for military satellites and other space programs.
DirecTV, a former subsidiary of Hughes Aircraft, is headquartered in El Segundo for this reason. SpaceX headquartered in the South Bay, is located in Hawthorne. Petroleum refining is another important component of the South Bay's economy. Major South Bay refiners include Tesoro, Phillips 66, PBF Energy and Valero; these refiners supply the lion's share of petroleum products for Southern California, as well as for Nevada and Arizona. As the Los Angeles region's oil fields are exhausted, most of the crude oil that feeds the refineries is brought in from terminals at the port. Local politicians and activists have long denounced the refineries for the amount of air pollution they generate, but in recent years these protests have been muted as the Port of Los Angeles has become the region's dominant polluter; the controversial practice of residue flaring returned to the forefront during the Sep
National Audubon Society
The National Audubon Society is a non-profit environmental organization dedicated to conservation. Located in the United States and incorporated in 1905, Audubon is one of the oldest of such organizations in the world and uses science and grassroots advocacy to advance its conservation mission, it is named in honor of John James Audubon, a Franco-American ornithologist and naturalist who painted and described the birds of North America in his famous book Birds of America published in sections between 1827 and 1838. The society has nearly 500 local chapters, each of, an independent 501 non-profit organization voluntarily affiliated with the National Audubon Society, which organize birdwatching field trips and conservation-related activities, it coordinates the Christmas Bird Count held each December in the U. S. a model of citizen science, in partnership with Cornell Lab of Ornithology, the Great Backyard Bird Count each February. Together with Cornell, Audubon created eBird, an online database for bird observation.
The National Audubon Society has many global partners to help birds that migrate beyond the U. S.'s borders, including BirdLife International based in Great Britain, Bird Studies Canada, many partners in Latin America and in the Caribbean. Audubon's International Alliances Program brings together people throughout the Western Hemisphere to work together to implement conservation solutions at Important Birds Areas; the society's main offices are in New York City and Washington, D. C. and it has state offices in about 24 states. It owns and operates a number of nature centers open to the public, located in urban settings, including New York City, Phoenix and Los Angeles, as well as at bird refuges and other natural areas. Audubon Centers help to forge lifelong connections between people and nature, developing stewards for conservation among young and diverse communities. In 1886, Forest and Stream editor George Bird Grinnell was appalled by the negligent mass slaughter of birds that he saw taking place.
As a boy, Grinnell had avidly read Ornithological Biography, a work by the bird painter John James Audubon. So when Grinnell decided to create an organization devoted to the protection of wild birds and their eggs, he did not have to go far for its namesake. Within a year of its foundation, the early Audubon Society claimed 39,000 members, it attained a membership of 48,862. Each member signed a pledge to "not molest birds." Prominent members included jurist Oliver Wendell Holmes, Jr. abolitionist minister Henry Ward Beecher, poet John Greenleaf Whittier. This society was discontinued, but the name and plan survived. Organizations for the protection of birds were not a wholly new idea. Before Grinnell's Audubon Society was organized, the American Ornithologists' Union, founded in 1883, was aware of the dangers facing many birds in the United States. There were, influential ornithologists who defended the collection of birds. In 1902, Charles B. Cory, the president-elect of the AOU refused to attend a meeting of the District of Columbia Audubon Society stating that "I do not protect birds.
I kill them."In 1895, the first Audubon Society was created. Cousins and Boston socialites Harriet Hemenway and Minna B. Hall, disturbed by the destruction left by plume hunters, organized a series of afternoon teas with other wealthy local women, encouraging them to avoid feathered garments, they sent literature asking these women to, in Hall's words, "join a society for the protection of birds the egret." That same year, they founded the Massachusetts Audubon Society. Over 900 women came together with Hemenway and Hall, across the country, many others were doing the same; these boycotts were successful, the efforts of the early society members helped bring about the end of the plume trade and assisted in the introduction of early conservation legislation such as the Migratory Bird Treaty Act. In 1896, Pennsylvania created their Audubon Society, during the next few years, bird lovers in many other states followed suit. St. Louis Audubon Society was established in 1916 as the St Louis Bird Club.
In 1944, the Bird Club became the first local Audubon chapter in the United States. The national committee of Audubon societies was organized at a meeting held in Washington, D. C. in 1902. 1905 saw the organization of the National Association of Audubon Societies for the Protection of Wild Birds and Animals. During this time, Albert Willcox provided financial support, more than $331,072 in 1905 and 1906. At the end of 1906, the Association had an interest-bearing endowment fund of more than $336,000 and an income from other sources of $9,000. Birds in the United States were threatened by market hunting as well as for the fashion industry. Pressure from shooting enthusiasts was intense. For example, great auks, whose habit of crowding together on rocks and beaches made them easy to hunt, had been driven to extinction early in the century. During one week in the spring of 1897, nature author Florence Merriam claimed to have seen 2,600 robins for sale in one market stall in Washington alone. By the start of the 20th century, the sale of bird flesh had never been greater.
The second great threat to the bird population was the desire for their plumage. In the late 1890s, the American Ornithologists' Union estimated that five million birds were killed annually for the fashion market. In the final quarter of the 19th century and whole birds, decorated the hair and dresses of women. Poachers killed game warden Guy Br
United States Geological Survey
The United States Geological Survey is a scientific agency of the United States government. The scientists of the USGS study the landscape of the United States, its natural resources, the natural hazards that threaten it; the organization has four major science disciplines, concerning biology, geography and hydrology. The USGS is a fact-finding research organization with no regulatory responsibility; the USGS is a bureau of the United States Department of the Interior. The USGS employs 8,670 people and is headquartered in Reston, Virginia; the USGS has major offices near Lakewood, Colorado, at the Denver Federal Center, Menlo Park, California. The current motto of the USGS, in use since August 1997, is "science for a changing world." The agency's previous slogan, adopted on the occasion of its hundredth anniversary, was "Earth Science in the Public Service." Since 2012, the USGS science focus is directed at six topical "Mission Areas", namely Climate and Land Use Change, Core Science Systems, Ecosystems and Minerals and Environmental Health, Natural Hazards, Water.
In December 2012, the USGS split the Energy and Minerals and Environmental Health Mission Area resulting in seven topical Mission Areas, with the two new areas being: Energy and Minerals and Environmental Health. Administratively, it is divided into six Regional Units. Other specific programs include: Earthquake Hazards Program monitors earthquake activity worldwide; the National Earthquake Information Center in Golden, Colorado on the campus of the Colorado School of Mines detects the location and magnitude of global earthquakes. The USGS runs or supports several regional monitoring networks in the United States under the umbrella of the Advanced National Seismic System; the USGS informs authorities, emergency responders, the media, the public, both domestic and worldwide, about significant earthquakes. It maintains long-term archives of earthquake data for scientific and engineering research, it conducts and supports research on long-term seismic hazards. USGS has released the UCERF California earthquake forecast.
As of 2005, the agency is working to create a National Volcano Early Warning System by improving the instrumentation monitoring the 169 volcanoes in U. S. territory and by establishing methods for measuring the relative threats posed at each site. The USGS National Geomagnetism Program monitors the magnetic field at magnetic observatories and distributes magnetometer data in real time; the USGS collaborates with Canadian and Mexican government scientists, along with the Commission for Environmental Cooperation, to produce the North American Environmental Atlas, used to depict and track environmental issues for a continental perspective. The USGS operates the streamgaging network for the United States, with over 7400 streamgages. Real-time streamflow data are available online. National Climate Change and Wildlife Science Center implements partner-driven science to improve understanding of past and present land use change, develops relevant climate and land use forecasts, identifies lands and communities that are most vulnerable to adverse impacts of change from the local to global scale.
Since 1962, the Astrogeology Research Program has been involved in global and planetary exploration and mapping. In collaboration with Stanford University, the USGS operates the USGS-Stanford Ion Microprobe Laboratory, a world-class analytical facility for U--Pb geochronology and trace element analyses of minerals and other earth materials. USGS operates a number of water related programs, notably the National Streamflow Information Program and National Water-Quality Assessment Program. USGS Water data is publicly available from their National Water Information System database; the USGS operates the National Wildlife Health Center, whose mission is "to serve the nation and its natural resources by providing sound science and technical support, to disseminate information to promote science-based decisions affecting wildlife and ecosystem health. The NWHC provides information, technical assistance, research and leadership on national and international wildlife health issues." It is the agency responsible for surveillance of H5N1 avian influenza outbreaks in the United States.
The USGS runs 17 biological research centers in the United States, including the Patuxent Wildlife Research Center. The USGS is investigating collaboration with the social networking site Twitter to allow for more rapid construction of ShakeMaps; the USGS produces several national series of topographic maps which vary in scale and extent, with some wide gaps in coverage, notably the complete absence of 1:50,000 scale topographic maps or their equivalent. The largest and best-known topographic series is the 7.5-minute, 1:24,000 scale, quadrangle, a non-metric scale unique to the United States. Each of these maps covers an area bounded by two lines of latitude and two lines of longitude spaced 7.5 minutes apart. Nearly 57,000 individual maps in this series cover the 48 contiguous states, Hawaii, U. S. territories, areas of Alaska near Anchorage and Prudhoe Bay. The area covered by each map varies with the latitude of its represented location due to convergence of the meridians. At lower latitudes, near 30° north, a 7.5-minute quadrangle contains an area of about 64 square miles.
At 49° north latitude, 49 square miles are contained within a quadrangle of that size. As a unique non-metric map scale, the 1:24,000 scale requires a separate and specialized romer scale for pl
Transpiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism; the remaining 97–99.5% is lost by transpiration and guttation. Leaf surfaces are dotted with pores called stomata, in most plants they are more numerous on the undersides of the foliage; the stomata are bordered by guard cells and their stomatal accessory cells that open and close the pore. Transpiration occurs through the stomatal apertures, can be thought of as a necessary "cost" associated with the opening of the stomata to allow the diffusion of carbon dioxide gas from the air for photosynthesis. Transpiration cools plants, changes osmotic pressure of cells, enables mass flow of mineral nutrients and water from roots to shoots. Two major factors influence the rate of water flow from the soil to the roots: the hydraulic conductivity of the soil and the magnitude of the pressure gradient through the soil.
Both of these factors influence the rate of bulk flow of water moving from the roots to the stomatal pores in the leaves via the xylem. Mass flow of liquid water from the roots to the leaves is driven in part by capillary action, but driven by water potential differences. If the water potential in the ambient air is lower than the water potential in the leaf airspace of the stomatal pore, water vapor will travel down the gradient and move from the leaf airspace to the atmosphere; this movement lowers the water potential in the leaf airspace and causes evaporation of liquid water from the mesophyll cell walls. This evaporation increases the tension on the water menisci in the cell walls and decrease their radius and thus the tension, exerted on the water in the cells; because of the cohesive properties of water, the tension travels through the leaf cells to the leaf and stem xylem where a momentary negative pressure is created as water is pulled up the xylem from the roots. In taller plants and trees, the force of gravity can only be overcome by the decrease in hydrostatic pressure in the upper parts of the plants due to the diffusion of water out of stomata into the atmosphere.
Water is absorbed at the roots by osmosis, any dissolved mineral nutrients travel with it through the xylem. The cohesion-tension theory explains. Water molecules stick together, or exhibit cohesion; as a water molecule evaporates from the surface of the leaf, it pulls on the adjacent water molecule, creating a continuous flow of water through the plant. Plants regulate the rate of transpiration by controlling the size of the stomatal apertures; the rate of transpiration is influenced by the evaporative demand of the atmosphere surrounding the leaf such as boundary layer conductance, temperature and incident sunlight. Soil water supply and soil temperature can influence stomatal opening, thus transpiration rate; the amount of water lost by a plant depends on its size and the amount of water absorbed at the roots. Transpiration accounts for most of the water loss by a plant by the leaves and young stems. Transpiration serves to evaporatively cool plants, as the evaporating water carries away heat energy due to its large latent heat of vaporization of 2260 kJ per litre.
During a growing season, a leaf will transpire many times more water than its own weight. An acre of corn gives off about 3,000–4,000 gallons of water each day, a large oak tree can transpire 40,000 gallons per year; the transpiration ratio is the ratio of the mass of water transpired to the mass of dry matter produced. Transpiration rates of plants can be measured by a number of techniques, including potometers, porometers, photosynthesis systems and thermometric sap flow sensors. Isotope measurements indicate. Recent evidence from a global study of water stable isotopes shows that transpired water is isotopically different from groundwater and streams; this suggests that soil water is not as well mixed as assumed. Desert plants have specially adapted structures, such as thick cuticles, reduced leaf areas, sunken stomata and hairs to reduce transpiration and conserve water. Many cacti conduct photosynthesis in succulent stems, rather than leaves, so the surface area of the shoot is low. Many desert plants have a special type of photosynthesis, termed crassulacean acid metabolism or CAM photosynthesis, in which the stomata are closed during the day and open at night when transpiration will be lower.
To maintain the pressure gradient necessary for a plant to remain healthy they must continuously uptake water with their roots. They need to be able to meet the demands of water lost due to transpiration. If a plant is incapable of bringing in enough water to remain in equilibrium with transpiration an event known as cavitation occurs. Cavitation is when the plant cannot supply its xylem with adequate water so instead of being filled with water the xylem begins to be filled with water vapor; these particles of water vapor form blockages within the xylem of the plant. This prevents the plant from being able to transport water throughout its vascular system. There is no apparent pattern of. If not taken care of, cavitation can cause a plant to reach its permanent wilting point, die. Therefore, the plant must have a method by which to remove this cavitation blockage, or it must create
A landscape is the visible features of an area of land, its landforms, how they integrate with natural or man-made features. A landscape includes the physical elements of geophysically defined landforms such as mountains, water bodies such as rivers, lakes and the sea, living elements of land cover including indigenous vegetation, human elements including different forms of land use and structures, transitory elements such as lighting and weather conditions. Combining both their physical origins and the cultural overlay of human presence created over millennia, landscapes reflect a living synthesis of people and place, vital to local and national identity; the character of a landscape helps define the self-image of the people who inhabit it and a sense of place that differentiates one region from other regions. It is the dynamic backdrop to people's lives. Landscape can be as varied as a landscape park or wilderness; the Earth has a vast range of landscapes, including the icy landscapes of polar regions, mountainous landscapes, vast arid desert landscapes and coastal landscapes, densely forested or wooded landscapes including past boreal forests and tropical rainforests, agricultural landscapes of temperate and tropical regions.
The activity of modifying the visible features of an area of land is referred to as landscaping. There are several definitions of. In common usage however, a landscape refers either to all the visible features of an area of land considered in terms of aesthetic appeal, or to a pictorial representation of an area of countryside within the genre of landscape painting; when people deliberately improve the aesthetic appearance of a piece of land—by changing contours and vegetation, etc.—it is said to have been landscaped, though the result may not constitute a landscape according to some definitions. The word landscape arrived in England—and therefore into the English language—after the fifth century, following the arrival of the Anglo-Saxons; the term landscape emerged around the turn of the sixteenth century to denote a painting whose primary subject matter was natural scenery. Land may be taken in its sense of something; the suffix ‑scape is equivalent to the more common English suffix ‑ship. The roots of ‑ ship are etymologically akin to Old English scyppan, meaning to shape.
The suffix ‑schaft is related to the verb schaffen, so that ‑ship and shape are etymologically linked. The modern form of the word, with its connotations of scenery, appeared in the late sixteenth century when the term landschap was introduced by Dutch painters who used it to refer to paintings of inland natural or rural scenery; the word landscape, first recorded in 1598, was borrowed from a Dutch painters' term. The popular conception of the landscape, reflected in dictionaries conveys both a particular and a general meaning, the particular referring to an area of the Earth's surface and the general being that which can be seen by an observer. An example of this second usage can be found as early as 1662 in the Book of Common Prayer: Could we but climb where Moses stood, And view the landscape over.. There are several words that are associated with the word landscape: Scenery: The natural features of a landscape considered in terms of their appearance, esp. when picturesque: spectacular views of mountain scenery.
Setting: In works of narrative, it includes the historical moment in time and geographic location in which a story takes place, helps initiate the main backdrop and mood for a story. Picturesque: The word means "in the manner of a picture. Gilpin’s Essay on Prints defined picturesque as "a term expressive of that peculiar kind of beauty, agreeable in a picture". A view: "A sight or prospect of some landscape or extended scene. Wilderness: An uncultivated and inhospitable region. See Natural landscape. Cityscape: The urban equivalent of a landscape. In the visual arts a cityscape is an artistic representation, such as a painting, print or photograph, of the physical aspects of a city or urban area. Seascape: A photograph, painting, or other work of art which depicts the sea, in other words an example of marine art. Geomorphology is the scientific study of the origin and evolution of topographic and bathymetric features created by physical or chemical processes operating at or near Earth's surface.
Geomorphologists seek to understand why landscapes look the way they do, to understand landform history and dynamics and to predict changes through a combination of field observations, physical experiments and numerical modeling. Geomorphology is practiced within physical geography, geodesy, engineering geology and geotechnical engineering; this broad base of interests contributes to many research interests within the field. The surface of Earth is modified by a combination of surface processes that sculpt landscapes, geologic processes that cause tectonic uplift and subsidence, shape the coastal geography. Surface processes comprise the action of water, ice and living things on the surface of the Earth, along with chemical reactions that form soils and alter material properties
In ecology, a habitat is the type of natural environment in which a particular species of organism lives. It is characterized by both biological features. A species' habitat is those places where it can find food, shelter and mates for reproduction; the physical factors are for example soil, range of temperature, light intensity as well as biotic factors such as the availability of food and the presence or absence of predators. Every organism has certain habitat needs for the conditions in which it will thrive, but some are tolerant of wide variations while others are specific in their requirements. A habitat is not a geographical area, it can be the interior of a stem, a rotten log, a rock or a clump of moss, for a parasitic organism it is the body of its host, part of the host's body such as the digestive tract, or a single cell within the host's body. Habitat types include polar, temperate and tropical; the terrestrial vegetation type may be forest, grassland, semi-arid or desert. Fresh water habitats include marshes, rivers and ponds, marine habitats include salt marshes, the coast, the intertidal zone, reefs, the open sea, the sea bed, deep water and submarine vents.
Habitats change over time. This may be due to a violent event such as the eruption of a volcano, an earthquake, a tsunami, a wildfire or a change in oceanic currents. Other changes come as a direct result of human activities; the introduction of alien species can have a devastating effect on native wildlife, through increased predation, through competition for resources or through the introduction of pests and diseases to which the native species have no immunity. The word "habitat" has been in use since about 1755 and derives from the Latin habitāre, to inhabit, from habēre, to have or to hold. Habitat can be defined as the natural environment of an organism, the type of place in which it is natural for it to live and grow, it is similar in meaning to a biotope. The chief environmental factors affecting the distribution of living organisms are temperature, climate, soil type and light intensity, the presence or absence of all the requirements that the organism needs to sustain it. Speaking, animal communities are reliant on specific types of plant communities.
Some plants and animals are generalists, their habitat requirements are met in a wide range of locations. The small white butterfly for example is found on all the continents of the world apart from Antarctica, its larvae feed on a wide range of Brassicas and various other plant species, it thrives in any open location with diverse plant associations. The large blue butterfly is much more specific in its requirements. Disturbance is important in the creation of biodiverse habitats. In the absence of disturbance, a climax vegetation cover develops that prevents the establishment of other species. Wildflower meadows are sometimes created by conservationists but most of the flowering plants used are either annuals or biennials and disappear after a few years in the absence of patches of bare ground on which their seedlings can grow. Lightning strikes and toppled trees in tropical forests allow species richness to be maintained as pioneering species move in to fill the gaps created. Coastal habitats can become dominated by kelp until the seabed is disturbed by a storm and the algae swept away, or shifting sediment exposes new areas for colonisation.
Another cause of disturbance is when an area may be overwhelmed by an invasive introduced species, not kept under control by natural enemies in its new habitat. Terrestrial habitat types include forests, grasslands and deserts. Within these broad biomes are more specific habitats with varying climate types, temperature regimes, soils and vegetation types. Many of these habitats grade into each other and each one has its own typical communities of plants and animals. A habitat may suit a particular species well, but its presence or absence at any particular location depends to some extent on chance, on its dispersal abilities and its efficiency as a coloniser. Freshwater habitats include rivers, lakes, ponds and bogs. Although some organisms are found across most of these habitats, the majority have more specific requirements; the water velocity, its temperature and oxygen saturation are important factors, but in river systems, there are fast and slow sections, pools and backwaters which provide a range of habitats.
Aquatic plants can be floating, semi-submerged, submerged or grow in permanently or temporarily saturated soils besides bodies of water. Marginal plants provide important habitat for both invertebrates and vertebrates, submerged plants provide oxygenation of the water, absorb nutrients and play a part in the reduction of pollution. Marine habitats include brackish water, bays, the open sea, the intertidal zone, the sea bed and deep / shallow water zones. Further variations include rock pools, sand banks, brackish lagoons and pebbly beaches, seagrass beds, all supporting their own flora and fauna; the benth
Evaporation is a type of vaporization that occurs on the surface of a liquid as it changes into the gas phase. The surrounding gas must not be saturated with the evaporating substance; when the molecules of the liquid collide, they transfer energy to each other based on how they collide with each other. When a molecule near the surface absorbs enough energy to overcome the vapor pressure, it will escape and enter the surrounding air as a gas; when evaporation occurs, the energy removed from the vaporized liquid will reduce the temperature of the liquid, resulting in evaporative cooling. On average, only a fraction of the molecules in a liquid have enough heat energy to escape from the liquid; the evaporation will continue until an equilibrium is reached when the evaporation of the liquid is equal to its condensation. In an enclosed environment, a liquid will evaporate. Evaporation is an essential part of the water cycle; the sun drives evaporation of water from oceans, moisture in the soil, other sources of water.
In hydrology and transpiration are collectively termed evapotranspiration. Evaporation of water occurs when the surface of the liquid is exposed, allowing molecules to escape and form water vapor. With sufficient energy, the liquid will turn into vapor. For molecules of a liquid to evaporate, they must be located near the surface, they have to be moving in the proper direction, have sufficient kinetic energy to overcome liquid-phase intermolecular forces; when only a small proportion of the molecules meet these criteria, the rate of evaporation is low. Since the kinetic energy of a molecule is proportional to its temperature, evaporation proceeds more at higher temperatures; as the faster-moving molecules escape, the remaining molecules have lower average kinetic energy, the temperature of the liquid decreases. This phenomenon is called evaporative cooling; this is. Evaporation tends to proceed more with higher flow rates between the gaseous and liquid phase and in liquids with higher vapor pressure.
For example, laundry on a clothes line will dry more on a windy day than on a still day. Three key parts to evaporation are heat, atmospheric pressure, air movement. On a molecular level, there is no strict boundary between the vapor state. Instead, there is a Knudsen layer; because this layer is only a few molecules thick, at a macroscopic scale a clear phase transition interface cannot be seen. Liquids that do not evaporate visibly at a given temperature in a given gas have molecules that do not tend to transfer energy to each other in a pattern sufficient to give a molecule the heat energy necessary to turn into vapor. However, these liquids are evaporating, it is just that the process is much slower and thus less visible. If evaporation takes place in an enclosed area, the escaping molecules accumulate as a vapor above the liquid. Many of the molecules return to the liquid, with returning molecules becoming more frequent as the density and pressure of the vapor increases; when the process of escape and return reaches an equilibrium, the vapor is said to be "saturated", no further change in either vapor pressure and density or liquid temperature will occur.
For a system consisting of vapor and liquid of a pure substance, this equilibrium state is directly related to the vapor pressure of the substance, as given by the Clausius–Clapeyron relation: ln = − Δ H v a p R where P1, P2 are the vapor pressures at temperatures T1, T2 ΔHvap is the enthalpy of vaporization, R is the universal gas constant. The rate of evaporation in an open system is related to the vapor pressure found in a closed system. If a liquid is heated, when the vapor pressure reaches the ambient pressure the liquid will boil; the ability for a molecule of a liquid to evaporate is based on the amount of kinetic energy an individual particle may possess. At lower temperatures, individual molecules of a liquid can evaporate if they have more than the minimum amount of kinetic energy required for vaporization. Note: Air used here is a common example. Concentration of the substance evaporating in the air If the air has a high concentration of the substance evaporating the given substance will evaporate more slowly.
Concentration of other substances in the air If the air is saturated with other substances, it can have a lower capacity for the substance evaporating. Flow rate of air This is in part related to the concentration points above. If "fresh" air is moving over the substance all the time the concentration of the substance in the air is less to go up with time, thus encouraging faster evaporation; this is the result of the boundary layer at the evaporation surface decreasing with flow velocity, decreasing the diffusion distance in the stagnant layer. The amount of minerals