A semi-arid climate or steppe climate is the climate of a region that receives precipitation below potential evapotranspiration, but not as low as a desert climate. There are different kinds of semi-arid climates, depending on variables such as temperature, they give rise to different biomes. A more precise definition is given by the Köppen climate classification, which treats steppe climates as intermediates between desert climates and humid climates in ecological characteristics and agricultural potential. Semi-arid climates tend to support short or scrubby vegetation and are dominated by either grasses or shrubs. To determine if a location has a semi-arid climate, the precipitation threshold must first be determined. Finding the precipitation threshold involves first multiplying the average annual temperature in °C by 20 adding 280 if 70% or more of the total precipitation is in the high-sun half of the year, or 140 if 30%–70% of the total precipitation is received during the applicable period, or 0 if less than 30% of the total precipitation is so received.
If the area's annual precipitation is less than the threshold but more than half the threshold, it is classified as a BS. Furthermore, to delineate "hot semi-arid climates" from "cold semi-arid climates", there are three used isotherms: Either a mean annual temperature of 18°C, or a mean temperature of 0°C or −3°C in the coldest month, so that a location with a "BS" type climate with the appropriate temperature above whichever isotherm is being used is classified as "hot semi-arid", a location with the appropriate temperature below the given isotherm is classified as "cold semi-arid". Hot semi-arid climates tend to be located in the 20s and 30s latitudes of the in proximity to regions with a tropical savanna or a humid subtropical climate; these climates tend to have hot, sometimes hot and warm to cool winters, with some to minimal precipitation. Hot semi-arid climates are most found around the fringes of subtropical deserts. Hot semi-arid climates are most found in Africa and South Asia. In Australia, a large portion of the Outback surrounding the central desert regions lies within the hot semi-arid climate region.
In South Asia, both India and sections of Pakistan experiences the seasonal effects of monsoons and feature short but well-defined wet seasons, but is not sufficiently wet overall to qualify as a tropical savanna climate. Hot semi-arid climates can be found in Europe, parts of North America, such as in Mexico, areas of the Southwestern United States, sections of South America such as the sertão, the Gran Chaco, on the poleward side of the arid deserts, where they feature a Mediterranean precipitation pattern, with rainless summers and wetter winters. Cold semi-arid climates tend to be located in elevated portions of temperate zones bordering a humid continental climate or a Mediterranean climate, they are found in continental interiors some distance from large bodies of water. Cold semi-arid climates feature warm to hot dry summers, though their summers are not quite as hot as those of hot semi-arid climates. Unlike hot semi-arid climates, areas with cold semi-arid climates tend to have cold winters.
These areas see some snowfall during the winter, though snowfall is much lower than at locations at similar latitudes with more humid climates. Areas featuring cold semi-arid climates tend to have higher elevations than areas with hot semi-arid climates, tend to feature major temperature swings between day and night, sometimes by as much as 20 °C or more in that time frame; these large diurnal temperature variations are seen in hot semi-arid climates. Cold semi-arid climates at higher latitudes tend to have dry winters and wetter summers, while cold semi-arid climates at lower latitudes tend to have precipitation patterns more akin to subtropical climates, with dry summers wet winters, wetter springs and autumns. Cold semi-arid climates are most found in Asia and North America. However, they can be found in Northern Africa, South Africa, sections of South America and sections of interior southern Australia and New Zealand. In climate classification, three isotherms means that delineate between hot and cold semi-arid climates — the 18°C average annual temperature or that of the coldest month, the warm side of the isotherm of choice defining a BSh climate from the BSk on the cooler side.
As a result of this, some areas can have climates that are classified as hot or cold semi-arid depending on the isotherm used. One such location is San Diego, which has cool summers for the latitude due to prevailing winds off the ocean but mild winters. Continental climate Dust Bowl Goyder's Line Köppen climate classification Palliser's Triangle Ustic Wave height
Relative humidity is the ratio of the partial pressure of water vapor to the equilibrium vapor pressure of water at a given temperature. Relative humidity depends on the pressure of the system of interest; the same amount of water vapor results in higher relative humidity in cool air than warm air. A related parameter is that of dewpoint; the relative humidity of an air–water mixture is defined as the ratio of the partial pressure of water vapor in the mixture to the equilibrium vapor pressure of water over a flat surface of pure water at a given temperature: ϕ = p H 2 O p H 2 O ∗. Relative humidity is expressed as a percentage. At 100 % relative humidity, the air is at its dewpoint. Climate control refers to the control of temperature and relative humidity in buildings and other enclosed spaces for the purpose of providing for human comfort and safety, of meeting environmental requirements of machines, sensitive materials and technical processes. Along with air temperature, mean radiant temperature, air speed, metabolic rate, clothing level, relative humidity plays a role in human thermal comfort.
According to ASHRAE Standard 55-2017: Thermal Environmental Conditions for Human Occupancy, indoor thermal comfort can be achieved through the PMV method with relative humidities ranging from 0% to 100%, depending on the levels of the other factors contributing to thermal comfort. However, the recommended range of indoor relative humidity in air conditioned buildings is 30-60%. In general, higher temperatures will require lower relative humidities to achieve thermal comfort compared to lower temperatures, with all other factors held constant. For example, with clothing level = 1, Metabolic rate = 1.1, air speed 0.1 m/s, a change in air temperature and mean radiant temperature from 20 degrees C to 24 degrees C would lower the maximum acceptable relative humidity from 100% to 65% to maintain thermal comfort conditions. The CBE Thermal Comfort Tool can be used to demonstrate the effect of relative humidity for specific thermal comfort conditions and it can be used to demonstrate compliance with ASHRAE Standard 55-2017.
When using the adaptive model to predict thermal comfort indoors, relative humidity is not taken into account. Although relative humidity is an important factor for thermal comfort, humans are more sensitive to variations in temperature than they are to changes in relative humidity. Relative humidity has a small effect on thermal comfort outdoors when air temperatures are low, a more pronounced effect at moderate air temperatures, a much stronger influence at higher air temperatures. In cold climates, the outdoor temperature causes lower capacity for water vapor to flow about, thus although it may be snowing and the relative humidity outdoors is high, once that air comes into a building and heats up, its new relative humidity is low, making the air dry, which can cause discomfort. Dry cracked. Low humidity causes tissue lining nasal passages to dry and become more susceptible to penetration of Rhinovirus cold viruses. Low humidity is a common cause of nosebleeds; the use of a humidifier in homes bedrooms, can help with these symptoms.
Indoor relative humidities should be kept above 30% to reduce the likelihood of the occupant's nasal passages drying out. Humans can be comfortable within a wide range of humidities depending on the temperature—from 30% to 70%—but ideally between 50% and 60%. Low humidity can create discomfort, respiratory problems, aggravate allergies in some individuals. In the winter, it is advisable to maintain relative humidity above. Low relative humidities may cause eye irritation. For climate control in buildings using HVAC systems, the key is to maintain the relative humidity at a comfortable range—low enough to be comfortable but high enough to avoid problems associated with dry air; when the temperature is high and the relative humidity is low, evaporation of water is rapid. Wooden furniture can shrink; when the temperature is low and the relative humidity is high, evaporation of water is slow. When relative humidity approaches 100 percent, condensation can occur on surfaces, leading to problems with mold, corrosion and other moisture-related deterioration.
Condensation can pose a safety risk as it can promote the growth of mold and wood rot as well as freezing emergency exits shut. Certain production and technical processes and treatments in factories, laboratories and other facilities require specific relative humidity levels to be maintained using humidifiers and associated control systems; the basic principles for buildings, above apply to vehicles. In addition, there may be safety considerations. For instance, high humidity inside a vehicle can lead to problems of condensation, such
Sunshine duration or sunshine hours is a climatological indicator, measuring duration of sunshine in given period for a given location on Earth expressed as an averaged value over several years. It is a general indicator of cloudiness of a location, thus differs from insolation, which measures the total energy delivered by sunlight over a given period. Sunshine duration is expressed in hours per year, or in hours per day; the first measure indicates the general sunniness of a location compared with other places, while the latter allows for comparison of sunshine in various seasons in the same location. Another often-used measure is percentage ratio of recorded bright sunshine duration and daylight duration in the observed period. An important use of sunshine duration data is to characterize the climate of sites of health resorts; this takes into account the psychological effect of strong solar light on human well-being. It is used to promote tourist destinations. If the Sun were to be above the horizon 50% of the time for a standard year consisting of 8,760 hours, apparent maximal daytime duration would be 4,380 hours for any point on Earth.
However, there are physical and astronomical effects. Namely, atmospheric refraction allows the Sun to be still visible when it physically sets below the horizon. For that reason, average daytime is longest in polar areas, where the apparent Sun spends the most time around the horizon. Places on the Arctic Circle have the longest total annual daytime, 4,647 hours, while the North Pole receives 4,575; because of elliptic nature of the Earth's orbit, the Southern Hemisphere is not symmetrical: the Antarctic Circle, with 4,530 hours of daylight, receives five days less of sunshine than its antipodes. The Equator has a total daytime of 4,422 hours per year. Given the theoretical maximum of daytime duration for a given location, there is a practical consideration at which point the amount of daylight is sufficient to be treated as a "sunshine hour". "Bright" sunshine hours represent the total hours when the sunlight is stronger than a specified threshold, as opposed to just "visible" hours. "Visible" sunshine, for example, occurs around sunrise and sunset, but is not strong enough to excite the sensor.
Measurement is performed by instruments called sunshine recorders. For the specific purpose of sunshine duration recording, Campbell–Stokes recorders are used, which use a spherical glass lens to focus the sun rays on a specially designed tape; when the intensity exceeds a pre-determined threshold, the tape burns. The total length of the burn trace is proportional to the number of bright hours. Another type of recorder is the Jordan sunshine recorder. Newer, electronic recorders have more stable sensitivity than that of the paper tape. In order to harmonize the data measured worldwide, in 1962 the World Meteorological Organization defined a standardized design of the Campbell–Stokes recorder, called an Interim Reference Sunshine Recorder. In 2003, the sunshine duration was defined as the period during which direct solar irradiance exceeds a threshold value of 120 W/m². Sunshine duration follows a general geographic pattern: subtropical latitudes have the highest sunshine values, because these are the locations of the eastern sides of the subtropical high pressure systems, associated with the large-scale descent of air from the upper-level tropopause.
Many of the world's driest climates are found adjacent to the eastern sides of the subtropical highs, which create stable atmospheric conditions, little convective overturning, little moisture and cloud cover. Desert regions, with nearly constant high pressure aloft and rare condensation—like North Africa, the Southwestern United States, Western Australia, the Middle East—are examples of hot, dry climates where sunshine duration values are high; the two major areas with the highest sunshine duration, measured as annual average, are the central and the eastern Sahara Desert—covering vast desert countries such as Egypt, Libya and Niger—and the Southwestern United States. The city claiming the official title of the sunniest in the world is Yuma, with over 4,000 hours of bright sunshine annually, but many climatological books suggest there may be sunnier areas in North Africa. In the belt encompassing northern Chad and the Tibesti Mountains, northern Sudan, southern Libya, Upper Egypt, annual sunshine duration is estimated at over 4,000 hours.
There is a smaller, isolated area of sunshine maximum in the heart of the western section of the Sahara Desert around the Eglab Massif and the Erg Chech, along the borders of Algeria and Mali where the 4,000-hour mark is exceeded, too. Some places in the interior of the Arabian Peninsula receive 3,600–3,800 hours of bright sunshine annually; the largest sun-baked region in the world is North Africa. The sunniest month in the world is December in Eastern Antarctica, with 23 hours of bright sun daily. Conversely, higher latitudes lying in stormy westerlies have much cloudier and more unstable and rainy weather, have the lowest values of sunshine duration annually. Temperate oceanic climates like those in northwestern Europe, the western coast of Canada, areas of New Zealand's South Island are examples of cool, wet, humid climates where cloudless sunshine duration values are low; the areas with the lowest sunshine duration annually lie over the polar oceans, as well as parts of northern Europe, southern Alaska, northern Russia, areas near the Sea of
Humahuaca is a city in the province of Jujuy, Argentina. It has 11,369 inhabitants as per the 2001 census, is the principal town of the Department of Humahuaca; the city is known for its location at the Quebrada de Humahuaca, a long valley east of the central Andean Altiplano. Humahuaca is located north of Tilcara and Purmamarca, in the colourful valley of Quebrada de Humahuaca. In the centre of the village there is a church tower which can be seen from the main square with a clock that chimes at 12 pm, after which a small door opens and a figure of Saint Francisco Solano comes out and makes the sign of the cross. Uña Ramos and Quena player, born in Humahuaca. Municipal information: Municipal Affairs Federal Institute, Municipal Affairs Secretariat, Ministry of Interior, Argentina. San Francisco Solano de la Bendición Coord. Geográficas + imágenes NASA, Google Verónico Cruz
A census is the procedure of systematically acquiring and recording information about the members of a given population. The term is used in connection with national population and housing censuses; the United Nations defines the essential features of population and housing censuses as "individual enumeration, universality within a defined territory and defined periodicity", recommends that population censuses be taken at least every 10 years. United Nations recommendations cover census topics to be collected, official definitions and other useful information to co-ordinate international practice; the word is of Latin origin: during the Roman Republic, the census was a list that kept track of all adult males fit for military service. The modern census is essential to international comparisons of any kind of statistics, censuses collect data on many attributes of a population, not just how many people there are. Censuses began as the only method of collecting national demographic data, are now part of a larger system of different surveys.
Although population estimates remain an important function of a census, including the geographic distribution of the population, statistics can be produced about combinations of attributes e.g. education by age and sex in different regions. Current administrative data systems allow for other approaches to enumeration with the same level of detail but raise concerns about privacy and the possibility of biasing estimates. A census can be contrasted with sampling in which information is obtained only from a subset of a population. Modern census data are used for research, business marketing, planning, as a baseline for designing sample surveys by providing a sampling frame such as an address register. Census counts are necessary to adjust samples to be representative of a population by weighting them as is common in opinion polling. Stratification requires knowledge of the relative sizes of different population strata which can be derived from census enumerations. In some countries, the census provides the official counts used to apportion the number of elected representatives to regions.
In many cases, a chosen random sample can provide more accurate information than attempts to get a population census. A census is construed as the opposite of a sample as its intent is to count everyone in a population rather than a fraction. However, population censuses rely on a sampling frame to count the population; this is the only way to be sure that everyone has been included as otherwise those not responding would not be followed up on and individuals could be missed. The fundamental premise of a census is that the population is not known and a new estimate is to be made by the analysis of primary data; the use of a sampling frame is counterintuitive as it suggests that the population size is known. However, a census is used to collect attribute data on the individuals in the nation; this process of sampling marks the difference between historical census, a house to house process or the product of an imperial decree, the modern statistical project. The sampling frame used by census is always an address register.
Thus it is not known how many people there are in each household. Depending on the mode of enumeration, a form is sent to the householder, an enumerator calls, or administrative records for the dwelling are accessed; as a preliminary to the dispatch of forms, census workers will check any address problems on the ground. While it may seem straightforward to use the postal service file for this purpose, this can be out of date and some dwellings may contain a number of independent households. A particular problem is what are termed'communal establishments' which category includes student residences, religious orders, homes for the elderly, people in prisons etc; as these are not enumerated by a single householder, they are treated differently and visited by special teams of census workers to ensure they are classified appropriately. Individuals are counted within households and information is collected about the household structure and the housing. For this reason international documents refer to censuses of housing.
The census response is made by a household, indicating details of individuals resident there. An important aspect of census enumerations is determining which individuals can be counted from which cannot be counted. Broadly, three definitions can be used: de facto residence; this is important to consider individuals who have temporary addresses. Every person should be identified uniquely as resident in one place but where they happen to be on Census Day, their de facto residence, may not be the best place to count them. Where an individual uses services may be more useful and this is at their usual, or de jure, residence. An individual may be represented at a permanent address a family home for students or long term migrants, it is necessary to have a precise definition of residence to decide whether visitors to a country should be included in the population count. This is becoming more important as students travel abroad for education for a period of several years. Other groups causing problems of enumeration are new born babies, people away on holiday, people moving home around census day, people without a fixed address.
People having second homes because of working in another part of the country or retaining a holiday cottage are dif
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
Argentina the Argentine Republic, is a country located in the southern half of South America. Sharing the bulk of the Southern Cone with Chile to the west, the country is bordered by Bolivia and Paraguay to the north, Brazil to the northeast and the South Atlantic Ocean to the east, the Drake Passage to the south. With a mainland area of 2,780,400 km2, Argentina is the eighth-largest country in the world, the fourth largest in the Americas, the largest Spanish-speaking nation; the sovereign state is subdivided into twenty-three provinces and one autonomous city, Buenos Aires, the federal capital of the nation as decided by Congress. The provinces and the capital exist under a federal system. Argentina claims sovereignty over part of Antarctica, the Falkland Islands, South Georgia and the South Sandwich Islands; the earliest recorded human presence in modern-day Argentina dates back to the Paleolithic period. The Inca Empire expanded to the northwest of the country in Pre-Columbian times; the country has its roots in Spanish colonization of the region during the 16th century.
Argentina rose as the successor state of the Viceroyalty of the Río de la Plata, a Spanish overseas viceroyalty founded in 1776. The declaration and fight for independence was followed by an extended civil war that lasted until 1861, culminating in the country's reorganization as a federation of provinces with Buenos Aires as its capital city; the country thereafter enjoyed relative peace and stability, with several waves of European immigration radically reshaping its cultural and demographic outlook. The almost-unparalleled increase in prosperity led to Argentina becoming the seventh wealthiest nation in the world by the early 20th century. Following the Great Depression in the 1930s, Argentina descended into political instability and economic decline that pushed it back into underdevelopment, though it remained among the fifteen richest countries for several decades. Following the death of President Juan Perón in 1974, his widow, Isabel Martínez de Perón, ascended to the presidency, she was overthrown in 1976 by a U.
S.-backed coup which installed a right-wing military dictatorship. The military government persecuted and murdered numerous political critics and leftists in the Dirty War, a period of state terrorism that lasted until the election of Raúl Alfonsín as President in 1983. Several of the junta's leaders were convicted of their crimes and sentenced to imprisonment. Argentina is a prominent regional power in the Southern Cone and Latin America, retains its historic status as a middle power in international affairs. Argentina has the second largest economy in South America, the third-largest in Latin America, membership in the G-15 and G-20 major economies, it is a founding member of the United Nations, World Bank, World Trade Organization, Union of South American Nations, Community of Latin American and Caribbean States and the Organization of Ibero-American States. Despite its history of economic instability, it ranks second highest in the Human Development Index in Latin America; the description of the country by the word Argentina has been found on a Venetian map in 1536.
In English the name "Argentina" comes from the Spanish language, however the naming itself is not Spanish, but Italian. Argentina means in Italian " of silver, silver coloured" borrowed from the Old French adjective argentine " of silver" > "silver coloured" mentioned in the 12th century. The French word argentine is the feminine form of argentin and derives from argent "silver" with the suffix -in; the Italian naming "Argentina" for the country implies Terra Argentina "land of silver" or Costa Argentina "coast of silver". In Italian, the adjective or the proper noun is used in an autonomous way as a substantive and replaces it and it is said l'Argentina; the name Argentina was first given by the Venetian and Genoese navigators, such as Giovanni Caboto. In Spanish and Portuguese, the words for "silver" are plata and prata and " of silver" is said plateado and prateado. Argentina was first associated with the silver mountains legend, widespread among the first European explorers of the La Plata Basin.
The first written use of the name in Spanish can be traced to La Argentina, a 1602 poem by Martín del Barco Centenera describing the region. Although "Argentina" was in common usage by the 18th century, the country was formally named "Viceroyalty of the Río de la Plata" by the Spanish Empire, "United Provinces of the Río de la Plata" after independence; the 1826 constitution included the first use of the name "Argentine Republic" in legal documents. The name "Argentine Confederation" was commonly used and was formalized in the Argentine Constitution of 1853. In 1860 a presidential decree settled the country's name as "Argentine Republic", that year's constitutional amendment ruled all the names since 1810 as valid. In the English language the country was traditionally called "the Argentine", mimicking the typical Spanish usage la Argentina and resulting from a mistaken shortening of the fuller name'Argentine Republic'.'The Argentine' fell out of fashion during the mid-to-late 20th century, now the country is referred to as "Argentina".
In the Spanish language "Argentina" is feminine, taking the feminine article "La" as the i