Battle of the Little Bighorn
The Battle of the Little Bighorn, known to the Lakota and other Plains Indians as the Battle of the Greasy Grass and commonly referred to as Custer's Last Stand, was an armed engagement between combined forces of the Lakota, Northern Cheyenne, Arapaho tribes and the 7th Cavalry Regiment of the United States Army. The battle, which resulted in the defeat of US forces, was the most significant action of the Great Sioux War of 1876, it took place on June 25–26, 1876, along the Little Bighorn River in the Crow Indian Reservation in southeastern Montana Territory. The fight was an overwhelming victory for the Lakota, Northern Cheyenne, Arapaho, who were led by several major war leaders, including Crazy Horse and Chief Gall, had been inspired by the visions of Sitting Bull; the US 7th Cavalry, a force of 700 men, suffered a major defeat while under the command of Lieutenant Colonel George Armstrong Custer. Five of the 7th Cavalry's twelve companies were annihilated and Custer was killed, as were two of his brothers, a nephew and a brother-in-law.
The total US casualty count included 268 dead and 55 wounded, including four Crow Indian scouts and at least two Arikara Indian scouts. Public response to the Great Sioux War varied in the immediate aftermath of the battle. Custer's widow soon worked to burnish her husband's memory, during the following decades Custer and his troops came to be considered iconic heroic, figures in American history; the battle, Custer's actions in particular, have been studied extensively by historians. Little Bighorn Battlefield National Monument honors those. In 1805, fur trader Francois Antoine Larocque reported joining a Crow camp in the Yellowstone area. On the way he noted that the Crow hunted buffalo on the "Small Horn River"; the US built Fort Raymond in 1807 for trade with the Crow. It was located near the confluence of the Yellowstone and the Bighorn River, about 40 miles north of the future battlefield; the area is first noted in the 1851 Treaty of Fort Laramie. In the latter half of the 19th century, tensions increased between the Native inhabitants of the Great Plains of the US and encroaching settlers.
This resulted in a series of conflicts known as the Sioux Wars, which took place from 1854-90. While some of the indigenous people agreed to relocate to ever-shrinking reservations, a number of them resisted, at times fiercely. On May 7, 1868, the valley of the Little Bighorn became a tract in the eastern part of the new Crow Indian Reservation in the center of the old Crow country. There were numerous skirmishes between the Sioux and Crow tribes so when the Sioux were in the valley in 1876 without the consent of the Crow tribe, the Crow supported the US Army to expel them; the battlefield is known as "Greasy Grass" to the Lakota, Dakota and most other Plains Indians. Among the Plains Tribes, the long-standing ceremonial tradition known as the Sun Dance was the most important religious event of the year, it is a time for prayer and personal sacrifice on behalf of the community, as well as making personal vows. Towards the end of spring in 1876, the Lakota and the Cheyenne held a Sun Dance, attended by a number of "Agency Indians" who had slipped away from their reservations.
During a Sun Dance around June 5, 1876, on Rosebud Creek in Montana, Sitting Bull, the spiritual leader of the Hunkpapa Lakota had a vision of "soldiers falling into his camp like grasshoppers from the sky." At the same time US military officials were conducting a summer campaign to force the Lakota and the Cheyenne back to their reservations, using infantry and cavalry in a so-called "three-pronged approach". Col. John Gibbon's column of six companies of the 7th Infantry and four companies of the 2nd Cavalry marched east from Fort Ellis in western Montana on March 30 to patrol the Yellowstone River. Brig. Gen. George Crook's column of ten companies of the 3rd Cavalry, five companies of the 2nd Cavalry, two companies of the 4th Infantry, three companies of the 9th Infantry moved north from Fort Fetterman in the Wyoming Territory on May 29, marching toward the Powder River area. Brig. Gen. Alfred Terry's column, including twelve companies of the 7th Cavalry under Lt. Col. George Armstrong Custer's immediate command, Companies C and G of the 17th U.
S. Infantry, the Gatling gun detachment of the 20th Infantry departed westward from Fort Abraham Lincoln in the Dakota Territory on May 17, they were accompanied by teamsters and packers with 150 wagons and a large contingent of pack mules that reinforced Custer. Companies C, D, I of the 6th U. S. Infantry moved along the Yellowstone River from Fort Buford on the Missouri River to set up a supply depot and joined Terry on May 29 at the mouth of the Powder River, they were joined there by the steamboat Far West, loaded with 200 tons of supplies from Fort Lincoln. The 7th Cavalry had been created just after the American Civil War. Many men were veterans of the war, including most of the leading officers. A significant portion of the regiment had served 4-1/2 years at Fort Riley, during which time it fought one major engagement and numerous skirmishes, experiencing casualties of 36 killed and 27 wounded. Six other troopers had died of 51 in cholera epidemics. In November 1868, while
A county seat is an administrative center, seat of government, or capital city of a county or civil parish. The term is used in Canada, Romania and the United States. County towns have a similar function in the United Kingdom and Republic of Ireland, in Jamaica. In most of the United States, counties are the political subdivisions of a state; the city, town, or populated place that houses county government is known as the seat of its respective county. The county legislature, county courthouse, sheriff's department headquarters, hall of records and correctional facility are located in the county seat though some functions may be located or conducted in other parts of the county if it is geographically large. A county seat is but not always, an incorporated municipality; the exceptions include the county seats of counties that have no incorporated municipalities within their borders, such as Arlington County, Virginia. Ellicott City, the county seat of Howard County, is the largest unincorporated county seat in the United States, followed by Towson, the county seat of Baltimore County, Maryland.
Some county seats may not be incorporated in their own right, but are located within incorporated municipalities. For example, Cape May Court House, New Jersey, though unincorporated, is a section of Middle Township, an incorporated municipality. In some of the colonial states, county seats include or included "Court House" as part of their name. In the Canadian provinces of Prince Edward Island, New Brunswick, Nova Scotia, the term "shire town" is used in place of county seat. County seats in Taiwan are the administrative centers of the counties. There are 13 county seats in Taiwan, which are in the forms of county-administered city, urban township or rural township. Most counties have only one county seat. However, some counties in Alabama, Georgia, Kentucky, Mississippi, New Hampshire, New York, Vermont have two or more county seats located on opposite sides of the county. An example is Harrison County, which lists both Biloxi and Gulfport as county seats; the practice of multiple county seat towns dates from the days.
There have been few efforts to eliminate the two-seat arrangement, since a county seat is a source of pride for the towns involved. There are 36 counties with multiple county seats in 11 states: Coffee County, Alabama St. Clair County, Alabama Arkansas County, Arkansas Carroll County, Arkansas Clay County, Arkansas Craighead County, Arkansas Franklin County, Arkansas Logan County, Arkansas Mississippi County, Arkansas Prairie County, Arkansas Sebastian County, Arkansas Yell County, Arkansas Columbia County, Georgia Lee County, Iowa Campbell County, Kentucky Kenton County, Kentucky Essex County, Massachusetts Middlesex County, Massachusetts Plymouth County, Massachusetts Bolivar County, Mississippi Carroll County, Mississippi Chickasaw County, Mississippi Harrison County, Mississippi Hinds County, Mississippi Jasper County, Mississippi Jones County, Mississippi Panola County, Mississippi Tallahatchie County, Mississippi Yalobusha County, Mississippi Jackson County, Missouri Hillsborough County, New Hampshire Seneca County, New York Bennington County, Vermont In New England, the town, not the county, is the primary division of local government.
Counties in this region have served as dividing lines for the states' judicial systems. Connecticut and Rhode Island have no county level of thus no county seats. In Vermont and Maine the county seats are designated shire towns. County government consists only of a Superior Court and Sheriff, both located in the respective shire town. Bennington County has two shire towns. In Massachusetts, most government functions which would otherwise be performed by county governments in other states are performed by town or city governments; as such, Massachusetts has dissolved many of its county governments, the state government now operates the registries of deeds and sheriff's offices in those counties. In Virginia, a county seat may be an independent city surrounded by, but not part of, the county of which it is the administrative center. Two counties in South Dakota have their county seat and government services centered in a neighboring county, their county-level services are provided by Fall River Tripp County, respectively.
In Louisiana, divided into parishes rather than counties, county seats are referred to as parish seats. Alaska is divided into boroughs rather than counties; the Unorganized Borough, which covers 49 % of Alaska's area, has equivalent. The state with the most counties is Texas, with 254, the state with the fewest counties is Delaware, with 3. County seat war Administrative center County town, administrative centres in Ireland and the UK Chef-lieu, administrative centres in Algeria, Luxembourg, France and Tunisia Municipality, equivalent to county in many c
Chicago the City of Chicago, is the most populous city in Illinois, as well as the third most populous city in the United States. With an estimated population of 2,716,450, it is the most populous city in the Midwest. Chicago is the principal city of the Chicago metropolitan area referred to as Chicagoland, the county seat of Cook County, the second most populous county in the United States; the metropolitan area, at nearly 10 million people, is the third-largest in the United States, the fourth largest in North America and the third largest metropolitan area in the world by land area. Located on the shores of freshwater Lake Michigan, Chicago was incorporated as a city in 1837 near a portage between the Great Lakes and the Mississippi River watershed and grew in the mid-nineteenth century. After the Great Chicago Fire of 1871, which destroyed several square miles and left more than 100,000 homeless, the city made a concerted effort to rebuild; the construction boom accelerated population growth throughout the following decades, by 1900 Chicago was the fifth largest city in the world.
Chicago made noted contributions to urban planning and zoning standards, including new construction styles, the development of the City Beautiful Movement, the steel-framed skyscraper. Chicago is an international hub for finance, commerce, technology, telecommunications, transportation, it is the site of the creation of the first standardized futures contracts at the Chicago Board of Trade, which today is the largest and most diverse derivatives market gobally, generating 20% of all volume in commodities and financial futures. O'Hare International Airport is the one of the busiest airports in the world, the region has the largest number of U. S. highways and greatest amount of railroad freight. In 2012, Chicago was listed as an alpha global city by the Globalization and World Cities Research Network, it ranked seventh in the entire world in the 2017 Global Cities Index; the Chicago area has one of the highest gross domestic products in the world, generating $680 billion in 2017. In addition, the city has one of the world's most diversified and balanced economies, not being dependent on any one industry, with no single industry employing more than 14% of the workforce.
Chicago's 58 million domestic and international visitors in 2018, made it the second most visited city in the nation, behind New York City's approximate 65 million visitors. The city ranked first place in the 2018 Time Out City Life Index, a global quality of life survey of 15,000 people in 32 cities. Landmarks in the city include Millennium Park, Navy Pier, the Magnificent Mile, the Art Institute of Chicago, Museum Campus, the Willis Tower, Grant Park, the Museum of Science and Industry, Lincoln Park Zoo. Chicago's culture includes the visual arts, film, comedy and music jazz, soul, hip-hop and electronic dance music including house music. Of the area's many colleges and universities, the University of Chicago, Northwestern University, the University of Illinois at Chicago are classified as "highest research" doctoral universities. Chicago has professional sports teams in each of the major professional leagues, including two Major League Baseball teams; the name "Chicago" is derived from a French rendering of the indigenous Miami-Illinois word shikaakwa for a wild relative of the onion, known to botanists as Allium tricoccum and known more as ramps.
The first known reference to the site of the current city of Chicago as "Checagou" was by Robert de LaSalle around 1679 in a memoir. Henri Joutel, in his journal of 1688, noted that the eponymous wild "garlic" grew abundantly in the area. According to his diary of late September 1687:...when we arrived at the said place called "Chicagou" which, according to what we were able to learn of it, has taken this name because of the quantity of garlic which grows in the forests in this region. The city has had several nicknames throughout its history such as the Windy City, Chi-Town, Second City, the City of the Big Shoulders, which refers to the city's numerous skyscrapers and high-rises. In the mid-18th century, the area was inhabited by a Native American tribe known as the Potawatomi, who had taken the place of the Miami and Sauk and Fox peoples; the first known non-indigenous permanent settler in Chicago was Jean Baptiste Point du Sable. Du Sable arrived in the 1780s, he is known as the "Founder of Chicago".
In 1795, following the Northwest Indian War, an area, to be part of Chicago was turned over to the United States for a military post by native tribes in accordance with the Treaty of Greenville. In 1803, the United States Army built Fort Dearborn, destroyed in 1812 in the Battle of Fort Dearborn and rebuilt; the Ottawa and Potawatomi tribes had ceded additional land to the United States in the 1816 Treaty of St. Louis; the Potawatomi were forcibly removed from their land after the Treaty of Chicago in 1833. On August 12, 1833, the Town of Chicago was organized with a population of about 200. Within seven years it grew to more than 4,000 people. On June 15, 1835, the first public land sales began with Edmund Dick Taylor as U. S. Receiver of Public Monies; the City of Chicago was incorporated on Saturday, March 4, 1837, for several decades was the world's fastest-growing city. As the site of the Chicago Portage, the city became an important transportation hub between the eastern and western United States.
Chicago's first railway and Chicago Union Railroad, the Illi
A ZIP Code is a postal code used by the United States Postal Service in a system it introduced in 1963. The term ZIP is an acronym for Zone Improvement Plan; the basic format consists of five digits. An extended ZIP+4 code was introduced in 1983 which includes the five digits of the ZIP Code, followed by a hyphen and four additional digits that reference a more specific location; the term ZIP Code was registered as a servicemark by the U. S. Postal Service, but its registration has since expired; the early history and context of postal codes began with postal district/zone numbers. The United States Post Office Department implemented postal zones for numerous large cities in 1943. For example: The "16" was the number of the postal zone in the specific city. By the early 1960s, a more organized system was needed, non-mandatory five-digit ZIP Codes were introduced nationwide on July 1, 1963; the USPOD issued its Publication 59: Abbreviations for Use with ZIP Code on October 1, 1963, with the list of two-letter state abbreviations which are written with both letters capitalized.
An earlier list in June had proposed capitalized abbreviations ranging from two to five letters. According to Publication 59, the two-letter standard was "based on a maximum 23-position line, because this has been found to be the most universally acceptable line capacity basis for major addressing systems", which would be exceeded by a long city name combined with a multi-letter state abbreviation, such as "Sacramento, Calif." along with the ZIP Code. The abbreviations have remained unchanged, with the exception of Nebraska, changed from NB to NE in 1969 at the request of the Canadian postal administration, to avoid confusion with the Canadian province of New Brunswick. Robert Moon is considered the father of the ZIP Code; the post office only credits Moon with the first three digits of the ZIP Code, which describe the sectional center facility or "sec center." An SCF is a central mail processing facility with those three digits. The fourth and fifth digits, which give a more precise locale within the SCF, were proposed by Henry Bentley Hahn Sr.
The SCF sorts mail to all post offices with those first three digits in their ZIP Codes. The mail is sorted according to the final two digits of the ZIP Code and sent to the corresponding post offices in the early morning. Sectional centers do not deliver mail and are not open to the public, most of their employees work the night shift. Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight. In the case of large cities, the last two digits coincide with the older postal zone number thus: In 1967, these became mandatory for second- and third-class bulk mailers, the system was soon adopted generally; the United States Post Office used a cartoon character, which it called Mr. ZIP, to promote the use of the ZIP Code, he was depicted with a legend such as "USE ZIP CODE" in the selvage of panes of postage stamps or on the covers of booklet panes of stamps. In 1971 Elmira Star-Gazette reporter Dick Baumbach found out the White House was not using a ZIP Code on its envelopes.
Herb Klein, special assistant to President Nixon, responded by saying the next printing of envelopes would include the ZIP Code. In 1983, the U. S. Postal Service introduced an expanded ZIP Code system that it called ZIP+4 called "plus-four codes", "add-on codes", or "add-ons". A ZIP+4 Code uses the basic five-digit code plus four additional digits to identify a geographic segment within the five-digit delivery area, such as a city block, a group of apartments, an individual high-volume receiver of mail, a post office box, or any other unit that could use an extra identifier to aid in efficient mail sorting and delivery. However, initial attempts to promote universal use of the new format met with public resistance and today the plus-four code is not required. In general, mail is read by a multiline optical character reader that instantly determines the correct ZIP+4 Code from the address—along with the more specific delivery point—and sprays an Intelligent Mail barcode on the face of the mail piece that corresponds to 11 digits—nine for the ZIP+4 Code and two for the delivery point.
For Post Office Boxes, the general rule is. The add-on code is one of the following: the last four digits of the box number, zero plus the last three digits of the box number, or, if the box number consists of fewer than four digits, enough zeros are attached to the front of the box number to produce a four-digit number. However, there is no uniform rule, so the ZIP+4 Code must be looked up individually for each box; the ZIP Code is translated into an Intelligent Mail barcode, printed on the mailpiece to make it easier for automated machines to sort. A barcode can be printed by the sender, it is better to let the post office put one on. In general, the post office uses OCR technology, though in some cases a human might have to read and enter the address. Customers who send bulk mail can get a discount on postage if they have printed the barcode themselves and have presorted the mai
An airline is a company that provides air transport services for traveling passengers and freight. Airlines utilize aircraft to supply these services and may form partnerships or alliances with other airlines for codeshare agreements. Airline companies are recognized with an air operating certificate or license issued by a governmental aviation body. Airlines vary in size, from small domestic airlines to full-service international airlines with double decker airplanes. Airline services can be categorized as being intercontinental, regional, or international, may be operated as scheduled services or charters; the largest airline is American Airlines Group. DELAG, Deutsche Luftschiffahrts-Aktiengesellschaft I was the world's first airline, it was founded on November 16, 1909, with government assistance, operated airships manufactured by The Zeppelin Corporation. Its headquarters were in Frankfurt; the first fixed wing scheduled airline was started on January 1, 1914, from St. Petersburg, Florida, to Tampa, Florida.
The four oldest non-dirigible airlines that still exist are Netherlands' KLM, Colombia's Avianca, Australia's Qantas, the Czech Republic's Czech Airlines. The earliest fixed wing airline in Europe was Aircraft Transport and Travel, formed by George Holt Thomas in 1916. Using a fleet of former military Airco DH.4A biplanes, modified to carry two passengers in the fuselage, it operated relief flights between Folkestone and Ghent. On 15 July 1919, the company flew a proving flight across the English Channel, despite a lack of support from the British government. Flown by Lt. H Shaw in an Airco DH.9 between RAF Hendon and Paris – Le Bourget Airport, the flight took 2 hours and 30 minutes at £21 per passenger. On 25 August 1919, the company used DH.16s to pioneer a regular service from Hounslow Heath Aerodrome to Le Bourget, the first regular international service in the world. The airline soon gained a reputation for reliability, despite problems with bad weather, began to attract European competition.
In November 1919, it won the first British civil airmail contract. Six Royal Air Force Airco DH.9A aircraft were lent to the company, to operate the airmail service between Hawkinge and Cologne. In 1920, they were returned to the Royal Air Force. Other British competitors were quick to follow – Handley Page Transport was established in 1919 and used the company's converted wartime Type O/400 bombers with a capacity for 12 passengers, to run a London-Paris passenger service; the first French airline was Société des lignes Latécoère known as Aéropostale, which started its first service in late 1918 to Spain. The Société Générale des Transports Aériens was created in late 1919, by the Farman brothers and the Farman F.60 Goliath plane flew scheduled services from Toussus-le-Noble to Kenley, near Croydon, England. Another early French airline was the Compagnie des Messageries Aériennes, established in 1919 by Louis-Charles Breguet, offering a mail and freight service between Le Bourget Airport and Lesquin Airport, Lille.
The first German airline to use heavier than air aircraft was Deutsche Luft-Reederei established in 1917 which started operating in February 1919. In its first year, the D. L. R. Operated scheduled flights on routes with a combined length of nearly 1000 miles. By 1921 the D. L. R. Network was more than 3000 km long, included destinations in the Netherlands and the Baltic Republics. Another important German airline was Junkers Luftverkehr, which began operations in 1921, it was a division of the aircraft manufacturer Junkers, which became a separate company in 1924. It operated joint-venture airlines in Austria, Estonia, Hungary, Norway, Poland and Switzerland; the Dutch airline KLM made its first flight in 1920, is the oldest continuously operating airline in the world. Established by aviator Albert Plesman, it was awarded a "Royal" predicate from Queen Wilhelmina, its first flight was from Croydon Airport, London to Amsterdam, using a leased Aircraft Transport and Travel DH-16, carrying two British journalists and a number of newspapers.
In 1921, KLM started scheduled services. In Finland, the charter establishing Aero O/Y was signed in the city of Helsinki on September 12, 1923. Junkers F.13 D-335 became the first aircraft of the company, when Aero took delivery of it on March 14, 1924. The first flight was between Helsinki and Tallinn, capital of Estonia, it took place on March 20, 1924, one week later. In the Soviet Union, the Chief Administration of the Civil Air Fleet was established in 1921. One of its first acts was to help found Deutsch-Russische Luftverkehrs A. G. a German-Russian joint venture to provide air transport from Russia to the West. Domestic air service began around the same time, when Dobrolyot started operations on 15 July 1923 between Moscow and Nizhni Novgorod. Since 1932 all operations had been carried under the name Aeroflot. Early European airlines tended to favor comfort – the passenger cabins were spacious with luxurious interiors – over speed and efficiency; the basic navigational capabilities of pilots at the time meant that delays due to the weather were commonplace.
By the early 1920s, small airlines were struggling to compete, there was a movement towards increased rationalization and consolidation. In 1924, Imperial Airways was formed from the merger of Instone Air Line Company, British Marine Air Navigation, Daimler Airway and Handley Page Transport Co Ltd. to allow British airlines to compete with stiff competition from French and German airlines that were enjoying heavy government subsidies. The ai
1890 United States Census
The Eleventh United States Census was taken beginning June 2, 1890. It determined the resident population of the United States to be 62,979,766—an increase of 25.5 percent over the 50,189,209 persons enumerated during the 1880 census. The data was tabulated by machine for the first time; the data reported that the distribution of the population had resulted in the disappearance of the American frontier. Most of the 1890 census materials were destroyed in a 1921 fire and fragments of the US census population schedule exist only for the states of Alabama, Illinois, New Jersey, New York, North Carolina, South Dakota, Texas, the District of Columbia; this was the first census in which a majority of states recorded populations of over one million, as well as the first in which multiple cities – New York as of 1880, Philadelphia – recorded populations of over one million. The census saw Chicago rank as the nation's second-most populous city, a position it would hold until 1990, in which Los Angeles would supplant it.
The 1890 census collected the following information: The 1890 census was the first to be compiled using methods invented by Herman Hollerith and was overseen by Superintendents Robert P. Porter and Carroll D. Wright. Data was entered on a machine readable medium, punched cards, tabulated by machine; the net effect of the many changes from the 1880 census: the larger population, the number of data items to be collected, the Census Bureau headcount, the volume of scheduled publications, the use of Hollerith's electromechanical tabulators, was to reduce the time required to process the census from eight years for the 1880 census to six years for the 1890 census. The total population of 62,947,714, the family, or rough, was announced after only six weeks of processing; the public reaction to this tabulation was disbelief, as it was believed that the "right answer" was at least 75,000,000. The United States census of 1890 showed a total of 248,253 Native Americans living in the United States, down from 400,764 Native Americans identified in the census of 1850.
The 1890 census announced that the frontier region of the United States no longer existed, that the Census Bureau would no longer track the westward migration of the U. S. population. Up to and including the 1880 census, the country had a frontier of settlement. By 1890, isolated bodies of settlement had broken into the unsettled area to the extent that there was hardly a frontier line; this prompted Frederick Jackson Turner to develop his Frontier Thesis. The original data for the 1890 Census is no longer available. All the population schedules were damaged in a fire in the basement of the Commerce Building in Washington, D. C. in 1921. Some 25 % of the materials were presumed another 50 % damaged by smoke and water; the damage to the records led to an outcry for a permanent National Archives. In December 1932, following standard federal record-keeping procedures, the Chief Clerk of the Bureau of the Census sent the Librarian of Congress a list of papers to be destroyed, including the original 1890 census schedules.
The Librarian was asked by the Bureau to identify any records which should be retained for historical purposes, but the Librarian did not accept the census records. Congress authorized destruction of that list of records on February 21, 1933, the surviving original 1890 census records were destroyed by government order by 1934 or 1935; the other censuses for which some information has been lost are the 1810 enumerations. Few sets of microdata from the 1890 census survive, but aggregate data for small areas, together with compatible cartographic boundary files, can be downloaded from the National Historical Geographic Information System. Mayo-Smith, Richmond, "The Eleventh Census of the United States". In: The Economic Journal, Vol. 1, p. 43 - 58 1891 U. S Census Report Contains 1890 Census results Historical US Census data from the U. S. Census Bureau website Hollerith 1890 Census Tabulator by Columbia University "The Fate of the 1890 Population Census" from the National Archives website
In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravity. The main forms of precipitation include drizzle, sleet, snow and hail. Precipitation occurs when a portion of the atmosphere becomes saturated with water vapor, so that the water condenses and "precipitates", thus and mist are not precipitation but suspensions, because the water vapor does not condense sufficiently to precipitate. Two processes acting together, can lead to air becoming saturated: cooling the air or adding water vapor to the air. Precipitation forms as smaller droplets coalesce via collision with other rain drops or ice crystals within a cloud. Short, intense periods of rain in scattered locations are called "showers."Moisture, lifted or otherwise forced to rise over a layer of sub-freezing air at the surface may be condensed into clouds and rain. This process is active when freezing rain occurs. A stationary front is present near the area of freezing rain and serves as the foci for forcing and rising air.
Provided necessary and sufficient atmospheric moisture content, the moisture within the rising air will condense into clouds, namely stratus and cumulonimbus. The cloud droplets will grow large enough to form raindrops and descend toward the Earth where they will freeze on contact with exposed objects. Where warm water bodies are present, for example due to water evaporation from lakes, lake-effect snowfall becomes a concern downwind of the warm lakes within the cold cyclonic flow around the backside of extratropical cyclones. Lake-effect snowfall can be locally heavy. Thundersnow is possible within lake effect precipitation bands. In mountainous areas, heavy precipitation is possible where upslope flow is maximized within windward sides of the terrain at elevation. On the leeward side of mountains, desert climates can exist due to the dry air caused by compressional heating. Most precipitation is caused by convection; the movement of the monsoon trough, or intertropical convergence zone, brings rainy seasons to savannah climes.
Precipitation is a major component of the water cycle, is responsible for depositing the fresh water on the planet. 505,000 cubic kilometres of water falls as precipitation each year. Given the Earth's surface area, that means the globally averaged annual precipitation is 990 millimetres, but over land it is only 715 millimetres. Climate classification systems such as the Köppen climate classification system use average annual rainfall to help differentiate between differing climate regimes. Precipitation may occur on other celestial bodies, e.g. when it gets cold, Mars has precipitation which most takes the form of frost, rather than rain or snow. Precipitation is a major component of the water cycle, is responsible for depositing most of the fresh water on the planet. 505,000 km3 of water falls as precipitation each year, 398,000 km3 of it over the oceans. Given the Earth's surface area, that means the globally averaged annual precipitation is 990 millimetres. Mechanisms of producing precipitation include convective and orographic rainfall.
Convective processes involve strong vertical motions that can cause the overturning of the atmosphere in that location within an hour and cause heavy precipitation, while stratiform processes involve weaker upward motions and less intense precipitation. Precipitation can be divided into three categories, based on whether it falls as liquid water, liquid water that freezes on contact with the surface, or ice. Mixtures of different types of precipitation, including types in different categories, can fall simultaneously. Liquid forms of precipitation include drizzle. Rain or drizzle that freezes on contact within a subfreezing air mass is called "freezing rain" or "freezing drizzle". Frozen forms of precipitation include snow, ice needles, ice pellets and graupel; the dew point is the temperature to which a parcel must be cooled in order to become saturated, condenses to water. Water vapor begins to condense on condensation nuclei such as dust and salt in order to form clouds. An elevated portion of a frontal zone forces broad areas of lift, which form clouds decks such as altostratus or cirrostratus.
Stratus is a stable cloud deck which tends to form when a cool, stable air mass is trapped underneath a warm air mass. It can form due to the lifting of advection fog during breezy conditions. There are four main mechanisms for cooling the air to its dew point: adiabatic cooling, conductive cooling, radiational cooling, evaporative cooling. Adiabatic cooling occurs when air expands; the air can rise due to convection, large-scale atmospheric motions, or a physical barrier such as a mountain. Conductive cooling occurs when the air comes into contact with a colder surface by being blown from one surface to another, for example from a liquid water surface to colder land. Radiational cooling occurs due to the emission of infrared radiation, either by the air or by the surface underneath. Evaporative cooling occurs when moisture is added to the air through evaporation, which forces the air temperature to cool to its wet-bulb temperature, or until it reaches saturation; the main ways water vapor is added to the air are: wind convergence into areas of upward motion, precipitation or virga falling from above, daytime heating evaporating water from the surface of oceans, water bodies or wet lan