The Sierra Club is an environmental organization in the United States. It was founded on May 28, 1892, in San Francisco, California, by the Scottish-American preservationist John Muir, who became its first president; the Sierra Club operates in the United States. Traditionally associated with the progressive movement, the club was one of the first large-scale environmental preservation organizations in the world, engages in lobbying politicians to promote environmentalist policies. Recent focuses of the club include promoting sustainable energy, mitigating global warming, opposing the use of coal; the club is known for its political endorsements, which are sought after by candidates in local elections. The Sierra Club is organized on both a local level; the club is divided into large chapters representing large geographic areas, some of which have tens of thousands of members. These chapters are divided into regional groups, special interest sections and task forces. While much activity is coordinated at a local level, the Club is a unified organization.
In addition to political advocacy, the Sierra Club organizes outdoor recreation activities, has been a notable organization for mountaineering and rock climbing in the United States. Members of the Sierra Club pioneered the Yosemite Decimal System of climbing, were responsible for a substantial amount of the early development of climbing. Much of this activity occurred in the group's namesake Sierra Nevada; the Sierra Club does not set standards for or regulate alpinism, but it organizes wilderness courses and occasional alpine expeditions for members. In California, the club, through its outdoor recreation groups, is considered the state's analogue to other state mountaineering clubs such as Mazamas or the Colorado Mountain Club; the Sierra Club's stated mission is "To explore and protect the wild places of the earth. Each year, five directors are elected to three-year terms, all club members are eligible to vote. A president is elected annually by the Board from among its members; the Executive Director runs the day-to-day operations of the group.
Michael Brune of Rainforest Action Network, has served as the organization's executive director since 2010. Brune succeeded Carl Pope. Pope stepped down amid discontent. Sierra Club members belong to local groups. National and local special-interest sections and task forces address particular issues; the national Sierra Club sets overarching rules. The club is known for engaging in two main activities: promoting and guiding outdoor recreational activities, done throughout the United States but in California, political activism to promote environmental causes. Richard M. Skinner of the Brookings Institution describes the Sierra Club as one of the United States' "leading environmental organizations"; the Sierra Club makes endorsements of individual candidates for elected office, which has substantial weight given the club's reputation and large membership. Journalist Robert Underwood Johnson had worked with John Muir on the successful campaign to create a large Yosemite National Park surrounding the much smaller state park, created in 1864.
This campaign succeeded in 1890. As early as 1889, Johnson had encouraged Muir to form an "association" to help protect the Sierra Nevada, preliminary meetings were held to plan the group. Others involved in the early planning included artist William Keith, Willis Linn Jepson, Willard Drake Johnson, Joseph LeConte and David Starr Jordan. In May 1892, a group of professors from the University of California and Stanford University helped Muir and attorney Warren Olney launch the new organization modeled after the eastern Appalachian Mountain Club; the Sierra Club's charter members elected Muir president, an office he held until his death in 1914. The Club's first goals included establishing Glacier and Mount Rainier national parks, convincing the California legislature to give Yosemite Valley to the U. S. federal government, preserving California's coastal redwoods. Muir escorted President Theodore Roosevelt through Yosemite in 1903, two years the California legislature ceded Yosemite Valley and Mariposa Grove to the federal government.
The Sierra Club won its first lobbying victory with the creation of the country's second national park, after Yellowstone in 1872. In the first decade of the 1900s, the Sierra Club became embroiled in the Hetch Hetchy Reservoir controversy that divided preservationists from "resource management" conservationists. In the late 19th century, the city of San Francisco was outgrowing its limited water supply, which depended on intermittent local springs and streams. In 1890, San Francisco mayor James D. Phelan proposed to build a dam and aqueduct on the Tuolumne River, one of the largest southern Sierra rivers, as a way to increase and stabilize the city's water supply. Gifford Pinchot, a progressive supporter of public utilities and head of the US Forest Service, which had jurisdiction over the national parks, supported the creation of the Hetch
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
A Mediterranean climate or dry summer climate is characterized by rainy winters and dry summers, with less than 40 mm of precipitation for at least three summer months. While the climate receives its name from the Mediterranean Basin, these are located on the western coasts of continents, between 30 and 45 degrees north and south of the equator between oceanic climates towards the poles, semi-arid and arid climates towards the equator. In essence, due to the seasonal shift of the subtropical high-pressure belts with the apparent movement of the Sun, a Mediterranean climate is an intermediate type between these other climates, with winters warmer and drier than oceanic climates and summers imitating sunny weather in semi-arid and arid climates; the resulting vegetation of Mediterranean climates are the garrigue or maquis in the Mediterranean Basin, the chaparral in California, the fynbos in South Africa, the mallee in Australia, the matorral in Chile. Areas with this climate are where the so-called "Mediterranean trinity" of agricultural products have traditionally developed: wheat and olive.
Most large, historic cities of the Mediterranean basin lie within Mediterranean climatic zones, including Algiers, Beirut, İzmir, Marseille, Rome and Valencia. Examples of major cities with Mediterranean climates that lie outside of the historic Mediterranean basin include major examples as Adelaide, Cape Town, Dushanbe, Los Angeles, Perth, San Francisco and Victoria. Under the Köppen climate classification, "hot dry-summer" climates and "cool dry-summer" climates are referred to as "Mediterranean". Under the Köppen climate system, the first letter indicates the climate group. Temperate climates or "C" zones have an average temperature above 0 °C, but below 18 °C, in their coolest months; the second letter indicates the precipitation pattern. Köppen has defined a dry summer month as a month with less than 30 mm of precipitation and with less than one-third that of the wettest winter month. Some, use a 40 mm level; the third letter indicates the degree of summer heat: "a" represents an average temperature in the warmest month above 22 °C, while "b" indicates the average temperature in the warmest month below 22 °C.
Under the Köppen classification, dry-summer climates occur on the western sides of continents. Csb zones in the Köppen system include areas not associated with Mediterranean climates but with Oceanic climates, such as much of the Pacific Northwest, much of southern Chile, parts of west-central Argentina, parts of New Zealand. Additional highland areas in the subtropics meet Cs requirements, though they, are not associated with Mediterranean climates, as do a number of oceanic islands such as Madeira, the Juan Fernández Islands, the western part of the Canary Islands, the eastern part of the Azores. Under Trewartha's modified Köppen climate classification, the two major requirements for a Cs climate are revised. Under Trewartha's system, at least eight months must have average temperatures of 10 °C or higher, the average annual precipitation must not exceed 900 mm. Thus, under this system, many Csb zones in the Köppen system become Do, the rare Csc zones become Eo, with only the classic dry-summer to warm winter, low annual rainfall locations included in the Mediterranean type climate.
During summer, regions of Mediterranean climate are influenced by cold ocean currents which keep the weather in the region dry and pleasant. Similar to desert climates, in many Mediterranean climates there is a strong diurnal character to daily temperatures in the warm summer months due to strong heating during the day from sunlight and rapid cooling at night. In winter, Mediterranean climate zones are no longer influenced by the cold ocean currents and therefore warmer water settles near land and causes clouds to form and rainfall becomes much more likely; as a result, areas with this climate receive all of their precipitation during their winter and spring seasons, may go anywhere from 3 to 6 months during the summer without having any significant precipitation. In the lower latitudes, precipitation decreases in both the winter and summer because they are closer to the Horse latitudes, thus bringing smaller amounts of rain. Toward the polar latitudes, total moisture increases; the rainfall tends to be more evenly distributed throughout the year in Southern Europe, while in the Eastern Mediterranean and in Southern California the summer is nearly or dry.
In places where evapotranspiration is higher, steppe climates tend to prevail, but still follow the weather pattern of the Mediterranean climate. The majority of the regions with Mediterranean climates have mild winters and warm summers; however winter and summer temperatures can vary between different regions with a Mediterranean climate. For instance, in the case of winters and Los Angeles experience mild temperatures in the winter, with frost and snowfall unknown, whereas Tashkent has colder winters with annual frosts and snowfall. Or to consider summer, Athens experiences rather high temperatures in that season. In contrast, San Francisco has cool summers with daily highs around 21 °C due to
In topography, prominence measures the height of a mountain or hill's summit relative to the lowest contour line encircling it but containing no higher summit within it. It is a measure of the independence of a summit. A peak's key col is a unique point on this contour line and the parent peak is some higher mountain, selected according to various objective criteria. There are at least two definitions of prominence: The prominence of a peak is the minimum height necessary to descend to get from the summit to any higher terrain, which can be calculated for a given peak in the following way: for every path connecting the peak to higher terrain, find the lowest point on the path. See Figure 1; the prominence of a peak is the height of the peak’s summit above the lowest contour line encircling it but containing no higher summit within it. This allows the prominence of points like Everest to be calculated, as long as a lowest point can be defined; the following mental exercise may illustrate the meaning of topographic prominence.
Imagine a peak and imagine that an imaginary sea level rises to the peak. Now lower the imaginary sea level and an imaginary island appears beneath your feet; the island will merge with other islands that emerge. The island will touch an island with a higher peak than the initial island The summit of that island is the parent peak of the summit, the point at which the two islands touch is the key col of the summit, the elevation rise from the key col to the summit is the topographic prominence of the summit; the parent peak may be either far from the subject peak. The summit of Mount Everest is the parent peak of Aconcagua at a distance of 17,755 km, as well as the parent of the South Summit of Mount Everest at a distance of 360 m; the key col may be close to the subject peak or far from it. The key col for Aconcagua, if sea level is disregarded, is the Bering Strait at a distance of 13,655 km; the key col for the South Summit of Mount Everest is about 100 m distant. Prominence is interesting to many mountaineers because it is an objective measurement, correlated with the subjective significance of a summit.
Peaks with low prominence are either subsidiary tops of some higher summit or insignificant independent summits. Peaks with high prominence tend to be the highest points around and are to have extraordinary views. Only summits with a sufficient degree of prominence are regarded as independent mountains. For example, the world's second-highest mountain is K2. While Mount Everest's South Summit is taller than K2, it is not considered an independent mountain because it is a sub-summit of the main summit. Many lists of mountains take topographic prominence as cutoff. John and Anne Nuttall's The Mountains of England and Wales uses a cutoff of 15 m, Alan Dawson's list of Marilyns uses 150 m.. In the contiguous United States, the famous list of "fourteeners" uses a cutoff of 300 ft / 91 m. In the U. S. 2000 ft of prominence has become an informal threshold that signifies that a peak has major stature. Lists with a high topographic prominence cutoff tend to favor isolated peaks or those that are the highest point of their massif.
While the use of prominence as a cutoff to form a list of peaks ranked by elevation is standard and is the most common use of the concept, it is possible to use prominence as a mountain measure in itself. This generates lists of peaks ranked by prominence, which are qualitatively different from lists ranked by elevation; such lists tend to emphasize isolated high peaks, such as range or island high points and stratovolcanoes. One advantage of a prominence-ranked list is that it needs no cutoff since a peak with high prominence is automatically an independent peak, it is common to define a peak's parent as a particular peak in the higher terrain connected to the peak by the key col. If there are many higher peaks there are various ways of defining which one is the parent, not based on geological or geomorphological factors; the "parent" relationship defines a hierarchy. For example, in Figure 1, the middle peak is a subpeak of the right peak, in turn a subpeak of the left peak, the highest point on its landmass.
In that example, there is no controversy over the hierarchy. These different definitions follow. A special case occurs for the highest point on an oceanic continent; some sources define no parent in this case. Called prominence island parentage, this is defined as follows. In figure 2 the key col of peak A is at the meeting place of two closed contours, one encircling A and the other containing at least one higher peak; the encirclement parent of A is the highest peak, inside this other contour. In terms of the
Köppen climate classification
The Köppen climate classification is one of the most used climate classification systems. It was first published by the Russian climatologist Wladimir Köppen in 1884, with several modifications by Köppen, notably in 1918 and 1936; the climatologist Rudolf Geiger introduced some changes to the classification system, thus sometimes called the Köppen–Geiger climate classification system. The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns; the five main groups are A, B, C, D, E. Each group and subgroup is represented by a letter. All climates are assigned a main group. All climates except for those in the E group are assigned a seasonal precipitation subgroup. For example, Af indicates a tropical rainforest climate; the system assigns a temperature subgroup for all groups other than those in the A group, indicated by the third letter for climates in B, C, D, the second letter for climates in E.
For example, Cfb indicates an oceanic climate with warm summers as indicated by the ending b. Climates are classified based on specific criteria unique to each climate type. Köppen designed the system based on his experience as a botanist, so the main climate groups are based on the different variety of vegetation that grows in climates belonging to each group. In addition to identifying climates, the system can be used to analyze ecosystem conditions and identify the main types of vegetation within climates. Due to its link with the plant life of a region, the system is useful in predicting future changes in plant life within a region; the Köppen climate classification system has been further modified, within the Trewartha climate classification system in the middle 1960s. The Trewartha system sought to create a more refined middle latitude climate zone, one of the criticisms of the Köppen system; the Köppen climate classification scheme divides climates into five main climate groups: A, B, C, D, E.
The second letter indicates the seasonal precipitation type, while the third letter indicates the level of heat. Summers are defined as the 6 month period, warmer either from April–September and/or October–March while winter is the 6 month period, cooler. Group A: Tropical climates This type of climate has every month of the year with an average temperature of 18 °C or higher, with significant precipitation. Af = Tropical rainforest climate. Am = Tropical monsoon climate. Aw or As = Tropical wet and dry or savanna climate. Group B: Dry climates This type of climate is defined by little precipitation. Multiply the average annual temperature in Celsius by 20 add 280 if 70% or more of the total precipitation is in the spring and summer months, or 140 if 30%–70% of the total precipitation is received during the spring and summer, or 0 if less than 30% of the total precipitation is received during the spring and summer. If the annual precipitation is less than 50% of this threshold, the classification is BW.
A third letter can be included to indicate temperature. H signified low-latitude climate while k signified middle-latitude climate, but the more common practice today in the United States, is to use h to mean the coldest month has an average temperature above 0 °C, with k denoting that at least one month's averages below 0 °C; the n is used to denote a climate characterized by frequent fog. BWh = Hot desert climate BWk = Cold desert climate BSh = Hot semi-arid climate BSk = Cold semi-arid climateGroup C: Temperate climates This type of climate has the coldest month averaging between 0 °C and 18 °C and at least one month averaging above 10 °C. Cfa = Humid subtropical climate. No significant precipitation difference between seasons. No dry months in the summer. Cfb = Temperate oceanic climate. No significant precipitation difference between seasons. Cfc = Subpolar oceanic climate. No significant precipitation difference between seasons. Cwa = Monsoon-influenced humid subtropical climate.
Spanish or Castilian is a Romance language that originated in the Castile region of Spain and today has hundreds of millions of native speakers in the Americas and Spain. It is the world's second-most spoken native language, after Mandarin Chinese. Spanish is a part of the Ibero-Romance group of languages, which evolved from several dialects of Vulgar Latin in Iberia after the collapse of the Western Roman Empire in the 5th century; the oldest Latin texts with traces of Spanish come from mid-northern Iberia in the 9th century, the first systematic written use of the language happened in Toledo capital of the Kingdom of Castile, in the 13th century. Beginning in 1492, the Spanish language was taken to the viceroyalties of the Spanish Empire, most notably to the newly-discovered Americas, as well as territories in Africa and the Philippines. Around 75% of modern Spanish vocabulary is derived from Latin and, through Latin, Ancient Greek. Spanish vocabulary has been in contact with Arabic from an early date, having developed during the Al-Andalus era in the Iberian Peninsula.
With around 8% of its vocabulary being Arabic in origin, this language is the second most important influence after Latin. It has been influenced by Basque, Celtiberian, by neighboring Ibero-Romance languages. Additionally, it has absorbed vocabulary from other languages the Romance languages—French, Portuguese, Catalan and Sardinian—as well as from Quechua and other indigenous languages of the Americas. Spanish is one of the six official languages of the United Nations, it is used as an official language by the European Union, the Organization of American States, the Union of South American Nations, the Community of Latin American and Caribbean States, the African Union and many other international organizations. Despite its large number of speakers, the Spanish language does not feature prominently in scientific writing, with the exception of the humanities, it is estimated that more than 437 million people speak Spanish as a native language, which qualifies it as second on the lists of languages by number of native speakers.
Instituto Cervantes claims that there are an estimated 477 million Spanish speakers with native competence and 572 million Spanish speakers as a first or second language—including speakers with limited competence—and more than 21 million students of Spanish as a foreign language. Spanish is the official or national language in Spain, Equatorial Guinea, 19 countries in the Americas. Speakers in the Americas total some 418 million, it is an optional language in the Philippines as it was a Spanish colony from 1569 to 1899. In the European Union, Spanish is the mother tongue of 8% of the population, with an additional 7% speaking it as a second language. Spanish is the most popular second language learned in the United States. In 2011 it was estimated by the American Community Survey that of the 55 million Hispanic United States residents who are five years of age and over, 38 million speak Spanish at home. According to a 2011 paper by U. S. Census Bureau Demographers Jennifer Ortman and Hyon B. Shin, the number of Spanish speakers is projected to rise through 2020 to anywhere between 39 million and 43 million, depending on the assumption one makes about immigration.
Most of these Spanish speakers will be Hispanic, with Ortman and Shin projecting between 37.5 million and 41 million Hispanic Spanish speakers by 2020. In Spain and in some other parts of the Spanish-speaking world, Spanish is called not only español but castellano, the language from the kingdom of Castile, contrasting it with other languages spoken in Spain such as Galician, Asturian, Catalan and Occitan; the Spanish Constitution of 1978 uses the term castellano to define the official language of the whole Spanish State in contrast to las demás lenguas españolas. Article III reads as follows: El castellano es la lengua española oficial del Estado.... Las demás lenguas españolas serán también oficiales en las respectivas Comunidades Autónomas... Castilian is the official Spanish language of the State.... The other Spanish languages shall be official in their respective Autonomous Communities... The Spanish Royal Academy, on the other hand uses the term español in its publications, but from 1713 to 1923 called the language castellano.
The Diccionario panhispánico de dudas states that, although the Spanish Royal Academy prefers to use the term español in its publications when referring to the Spanish language, both terms—español and castellano—are regarded as synonymous and valid. Two etymologies for español have been suggested; the Spanish Royal Academy Dictionary derives the term from the Provençal word espaignol, that in turn from the Medieval Latin word Hispaniolus,'from—or pertaining to—Hispania'. Other authorities attribute it to a supposed mediaeval Latin *hispaniōne, with the same meaning; the Spanish language evolved from Vulgar Latin, brought to the Iberian Peninsula by the Romans during the Second Punic War, beginning in 210 BC. Several pre-Roman languages —unrelated to Latin, some of them unrelated to Indo-European—were spoken in the Iberian Peninsula; these languages included Basque, Iberian and Gallaecian. The first documents to show traces of what is today regarded as the precursor of modern Spanish are from the 9th century.
Throughout the Middle Ages and into the modern era, the most important influences on the Spanish lexicon came from neighboring Romance languages—Mozarabic (Anda