Misplaced Pages

#241758

97-452: The Argentine Northwest comprises very distinct biomes , or geographical and climatic regions. From west to east they are: Besides the Yungas jungle on the eastern fringe of the region, the only fertile lands are those near the river basins, which have been irrigated extensively. Across millennia the erosive forces of these rivers has gradually created a multitude of red-rock canyons, such as

194-474: A microbiome is a mix of organisms that coexist in a defined space on a much smaller scale. For example, the human microbiome is the collection of bacteria, viruses, and other microorganisms that are present on or in a human body. A biota is the total collection of organisms of a geographic region or a time period, from local geographic scales and instantaneous temporal scales all the way up to whole-planet and whole-timescale spatiotemporal scales. The biotas of

291-416: A characteristic temperature-pressure curve. As air circulates vertically, the air takes on that characteristic gradient. When the air contains little water, this lapse rate is known as the dry adiabatic lapse rate: the rate of temperature decrease is 9.8 °C/km ( 5.4 °F per 1,000 ft) (3.0 °C/1,000 ft). The reverse occurs for a sinking parcel of air. When the environmental lapse rate

388-606: A gradient (2), the moisture gradient, to express the above conclusions in what is known as the Whittaker classification scheme. The scheme graphs average annual precipitation (x-axis) versus average annual temperature (y-axis) to classify biome-types. The multi-authored series Ecosystems of the World , edited by David W. Goodall , provides a comprehensive coverage of the major "ecosystem types or biomes" on Earth: The eponymously named Heinrich Walter classification scheme considers

485-517: A lower elevation. In both the Quebrada de Humahuaca and Calchaqui valleys, winters are cold with frosts that can occur between March and September. In the valleys in the south in La Rioja province and Catamarca province along with the southwest parts of Santiago del Estero Province which is part of the arid Chaco ecoregion, the climate is mild year long in terms of temperature. Temperatures during

582-424: A negligible role in transferring heat within the atmosphere; this is because the thermal conductivity of air is very low. The air is radiatively cooled by greenhouse gases (water vapor, carbon dioxide, etc.) and clouds emitting longwave thermal radiation to space. If radiation were the only way to transfer energy within the atmosphere, then the lapse rate near the surface would be roughly 40 °C/km and

679-411: A parcel of air at a given altitude has the same density as the other air at the same elevation. Convection carries hot, moist air upward and cold, dry air downward, with a net effect of transferring heat upward. This makes the air below cooler than it would otherwise be and the air above warmer. When convection happens, this shifts the environmental lapse rate towards the adiabatic lapse rate , which

776-465: A parcel rises to the level of free convection (LFC), after which it enters the free convective layer (FCL) and usually rises to the equilibrium level (EL). If the environmental lapse rate is larger than the dry adiabatic lapse rate, it has a superadiabatic lapse rate, the air is absolutely unstable — a parcel of air will gain buoyancy as it rises both below and above the lifting condensation level or convective condensation level. This often happens in

873-626: A seasonal low-pressure system east of the Andes (called the Chaco Low). During summer, the interaction between the South Atlantic high and the Chaco low causes the low-pressure system to bring northeasterly and easterly winds that carry moisture to the region, particularly in the northern parts. The movement of moist air into the region during the summer results in very high precipitation. Most of

970-499: A simplification of Holdridge's; more readily accessible, but missing Holdridge's greater specificity. Whittaker based his approach on theoretical assertions and empirical sampling. He had previously compiled a review of biome classifications. Whittaker's distinction between biome and formation can be simplified: formation is used when applied to plant communities only, while biome is used when concerned with both plants and animals. Whittaker's convention of biome-type or formation-type

1067-464: A swamp, can create different kinds of communities within the same biome. Schultz (1988, 2005) defined nine ecozones (his concept of ecozone is more similar to the concept of biome than to the concept of ecozone of BBC): Robert G. Bailey nearly developed a biogeographical classification system of ecoregions for the United States in a map published in 1976. He subsequently expanded

SECTION 10

#1732764828242

1164-473: A temperature gradient will arise in a column of still air in a gravitational field without external energy flows. This issue was addressed by James Clerk Maxwell in 1902, who established that if any temperature gradient forms, then that temperature gradient must be universal (i.e., the gradient must be same for all materials) or the Second Law of Thermodynamics would be violated. Maxwell also concluded that

1261-458: A temperature lapse rate of 6.50 °C/km (3.56 °F or 1.98 °C/1,000 ft) from sea level to 11 km (36,090 ft or 6.8 mi) . From 11 km up to 20 km (65,620 ft or 12.4 mi) , the constant temperature is −56.5 °C (−69.7 °F) , which is the lowest assumed temperature in the ISA. The standard atmosphere contains no moisture. Unlike the idealized ISA,

1358-433: A way to recognize the irreversible coupling of human and ecological systems at global scales and manage Earth's biosphere and anthropogenic biomes. Major anthropogenic biomes: The endolithic biome, consisting entirely of microscopic life in rock pores and cracks, kilometers beneath the surface, has only recently been discovered, and does not fit well into most classification schemes. Anthropogenic climate change has

1455-484: A year, owing to the high insolation, strong winds, and low humidity that exacerbates the dry conditions. Owing to the low precipitation in conjunction with the extreme climatic conditions, the Puna region has a water deficit in all months of the year. Although easterly winds are rare in the Puna region, they bring 88–96% of the precipitation to the area. Snowfall is rare, averaging less than 5 days of snow per year since most of

1552-503: Is woody plant encroachment , which can change grass savanna into shrub savanna. Average temperatures have risen more than twice the usual amount in both arctic and mountainous biomes, which leads to the conclusion that arctic and mountainous biomes are currently the most vulnerable to climate change. South American terrestrial biomes have been predicted to go through the same temperature trends as arctic and mountainous biomes. With its annual average temperature continuing to increase,

1649-492: Is 3,900 m (12,800 ft) and the terrain is mostly desert due to the higher elevations of the mountains on the east from both the Andes and the northwest extension of the Sierras Pampeanas , blocking most of the easterly winds from coming in. Precipitation in the Puna region averages less than 200 mm (7.9 in) a year while potential evapotranspiration ranges from 500 to 600 mm (20 to 24 in)

1746-485: Is a broader method to categorize similar communities. Whittaker used what he called "gradient analysis" of ecocline patterns to relate communities to climate on a worldwide scale. Whittaker considered four main ecoclines in the terrestrial realm. Along these gradients, Whittaker noted several trends that allowed him to qualitatively establish biome-types: Whittaker summed the effects of gradients (3) and (4) to get an overall temperature gradient and combined this with

1843-407: Is a distinct geographical region with specific climate , vegetation , and animal life . It consists of a biological community that has formed in response to its physical environment and regional climate . Biomes may span more than one continent. A biome encompasses multiple ecosystems within its boundaries. It can also comprise a variety of habitats . While a biome can cover small areas,

1940-421: Is a thermal gradient characteristic of vertically moving air packets. Because convection is available to transfer heat within the atmosphere, the lapse rate in the troposphere is reduced to around 6.5 °C/km and the greenhouse effect is reduced to a point where Earth has its observed surface temperature of around 288 K (15 °C; 59 °F). As convection causes parcels of air to rise or fall, there

2037-410: Is absent, in which case, the parcel must be heated from below to its convective temperature . The cloud base will be somewhere within the layer bounded by these parameters. The difference between the dry adiabatic lapse rate and the rate at which the dew point drops is around 4.5 °C per 1,000 m. Given a difference in temperature and dew point readings on the ground, one can easily find

SECTION 20

#1732764828242

2134-399: Is an important source of energy in the development of thunderstorms. While the dry adiabatic lapse rate is a constant 9.8 °C/km ( 5.4 °F per 1,000 ft, 3 °C/1,000 ft ), the moist adiabatic lapse rate varies strongly with temperature. A typical value is around 5 °C/km , ( 9 °F/km , 2.7 °F/1,000 ft , 1.5 °C/1,000 ft ). The formula for

2231-515: Is between the moist and dry adiabatic lapse rates, the air is conditionally unstable — an unsaturated parcel of air does not have sufficient buoyancy to rise to the LCL or CCL, and it is stable to weak vertical displacements in either direction. If the parcel is saturated it is unstable and will rise to the LCL or CCL, and either be halted due to an inversion layer of convective inhibition , or if lifting continues, deep, moist convection (DMC) may ensue, as

2328-482: Is characterized by being cold but sunny throughout the year. The diurnal range is large with a thermal amplitude that can exceed 40 °C (104.0 °F) due to the low humidity and the intense sunlight throughout the year. and the mean annual maximum and minimum temperatures are 16 °C (60.8 °F) and −4 °C (24.8 °F) respectively with frosts that can occur in any month as night temperatures can regularly fall below freezing. Absolute maximum temperatures in

2425-488: Is distributed irregularly owing to relief. As moist air reaches the eastern slopes of the mountains, this moist air raises up vertically, cooling adiabatically , leading to the formation of clouds which generate copious amounts of rain. The eastern slopes of the mountains can receive between 1,000 and 1,500 mm (39 and 59 in) of precipitation a year although some places can receive 2,500 mm (98 in) of precipitation per year owing to orographic precipitation . In

2522-659: Is exchanged with the environment is referred to as an adiabatic process . Air expands as it moves upward, and contracts as it moves downward. The expansion of rising air parcels, and the contraction of descending air parcels, are adiabatic processes, to a good approximation. When a parcel of air expands, it pushes on the air around it, doing thermodynamic work . Since the upward-moving and expanding parcel does work but gains no heat, it loses internal energy so that its temperature decreases. Downward-moving and contracting air has work done on it, so it gains internal energy and its temperature increases. Adiabatic processes for air have

2619-531: Is fairly large, particularly in the winter. In the Quebrada de Humahuaca valley in Jujuy province, north of Jujuy city, the diurnal range is large with a thermal amplitude between 16 and 20 °C (28.8 and 36.0 °F). A major reason for the large thermal amplitude is that during the day, there is intense radiation from the sun, causing the land to heat up while during the night, there is less radiation, causing

2716-687: Is highly variable both spatially and temporally. Temperatures in northwest Argentina vary with elevation. In the temperate valleys which includes the cities of Salta and Jujuy, they have a temperate climate, with mild temperatures in the summer (a mean of 20 °C (68.0 °F) in Salta, 21 °C (69.8 °F) in Jujuy in January) and extremely dry and cool winters with regular frosts (a mean of 10 °C (50.0 °F) in Salta and 10.5 °C (50.9 °F) in Jujuy in July). The diurnal range in these cities

2813-559: Is less than the adiabatic lapse rate the atmosphere is stable and convection will not occur. Only the troposphere (up to approximately 12 kilometres (39,000 ft) of altitude) in the Earth's atmosphere undergoes convection : the stratosphere does not generally convect. However, some exceptionally energetic convection processes, such as volcanic eruption columns and overshooting tops associated with severe supercell thunderstorms , may locally and temporarily inject convection through

2910-436: Is little heat transfer between those parcels and the surrounding air. Air has low thermal conductivity , and the bodies of air involved are very large; so transfer of heat by conduction is negligibly small. Also, intra-atmospheric radiative heat transfer is relatively slow and so is negligible for moving air. Thus, when air ascends or descends, there is little exchange of heat with the surrounding air. A process in which no heat

3007-432: Is not saturated with water vapor, i.e., with less than 100% relative humidity. The presence of water within the atmosphere (usually the troposphere) complicates the process of convection. Water vapor contains latent heat of vaporization . As a parcel of air rises and cools, it eventually becomes saturated ; that is, the vapor pressure of water in equilibrium with liquid water has decreased (as temperature has decreased) to

Argentine Northwest - Misplaced Pages Continue

3104-436: Is predominantly dry and hot and classified as subtropical . Owing to its rugged topography, the region is climatically diverse, depending on the elevation, temperature and distribution of precipitation. Consequentially, the vegetation will differ at these different climate types. In general, the climate can be divided into 2 main types: a cold arid or semi-arid climate at the higher elevations and warmer subtropical climate in

3201-408: Is stronger in locations where the lapse rate is stronger. In Antarctica, thermal inversions in the atmosphere (so that air at higher altitudes is warmer) sometimes cause the localized greenhouse effect to become negative (signifying enhanced radiative cooling to space instead of inhibited radiative cooling as is the case for a positive greenhouse effect). A question has sometimes arisen as to whether

3298-452: Is the specific heat at constant pressure. Assuming an atmosphere in hydrostatic equilibrium : where g is the standard gravity . Combining these two equations to eliminate the pressure, one arrives at the result for the dry adiabatic lapse rate (DALR), The DALR ( Γ d {\displaystyle \Gamma _{\text{d}}} ) is the temperature gradient experienced in an ascending or descending packet of air that

3395-554: Is the actual rate of decrease of temperature with altitude in the atmosphere at a given time and location. The ELR is the observed lapse rate, and is to be distinguished from the adiabatic lapse rate which is a theoretical construct. The ELR is forced towards the adiabatic lapse rate whenever air is moving vertically. As an average, the International Civil Aviation Organization (ICAO) defines an international standard atmosphere (ISA) with

3492-571: Is used as an international, non-regional, terminology—irrespectively of the continent in which an area is present, it takes the same biome name—and corresponds to his "zonobiome", "orobiome" and "pedobiome" (biomes determined by climate zone, altitude or soil). In the Brazilian literature, the term biome is sometimes used as a synonym of biogeographic province , an area based on species composition (the term floristic province being used when plant species are considered), or also as synonym of

3589-477: The Glossary of Meteorology is: Typically, the lapse rate is the negative of the rate of temperature change with altitude change: where Γ {\displaystyle \Gamma } (sometimes L {\displaystyle L} ) is the lapse rate given in units of temperature divided by units of altitude, T is temperature, and z is altitude. The environmental lapse rate (ELR),

3686-495: The International Civil Aviation Organization (ICAO). The environmental lapse rate is the decrease in temperature of air with altitude for a specific time and place (see below). It can be highly variable between circumstances. Lapse rate corresponds to the vertical component of the spatial gradient of temperature . Although this concept is most often applied to the Earth's troposphere , it can be extended to any gravitationally supported parcel of gas . A formal definition from

3783-647: The Lerma Valley which is surrounded by tall mountains (only the northeastern part of the valley is surrounded by shorter mountains), precipitation ranges from 695 mm (27.4 in) in Salta to 1,395 mm (54.9 in) in San Lorenzo, just 11 km (6.8 mi) away. Rainfall in the Lerma valley in Salta and in wetter valleys in Jujuy province, including its provincial capital , is mainly concentrated in

3880-613: The Quebrada de Humahuaca and the Valles Calchaquíes . West of these valleys the peaks of the Andes reach heights of over 6,000 metres (20,000 ft) and the Altiplano , an extensive 3,500-meter high plateau, dominates the landscape and continues far north into Bolive and Southern Peru. In February 2021, archaeologists from the University of Buenos Aires – National Scientific and Technical Research Council announced

3977-399: The Valles Calchaquíes , Tafí del Valle , and the capital cities of the provinces: San Miguel de Tucumán , San Fernando del Valle de Catamarca , Salta and San Salvador de Jujuy . The national parks of the region are: Baritú National Park , Calilegua National Park , El Rey National Park , Los Cardones National Park and Campo de los Alisos National Park . Besides the geography of

Argentine Northwest - Misplaced Pages Continue

4074-610: The World Wildlife Fund (WWF) developed a scheme that divided the world's land area into biogeographic realms (called "ecozones" in a BBC scheme), and these into ecoregions (Olson & Dinerstein, 1998, etc.). Each ecoregion is characterized by a main biome (also called major habitat type). This classification is used to define the Global 200 list of ecoregions identified by the WWF as priorities for conservation. For

4171-481: The Zonda wind , which occurs more during the winter months can affect these valleys in La Rioja province and Catamarca province can raise temperatures up to 35 °C (95.0 °F) with strong gusts, causing possible crop damage. Further west, in the Puna region next to Bolivia, temperatures are much colder, with a mean annual temperature of less than 10 °C (50.0 °F) owing to its high elevation. The Puna region

4268-434: The greenhouse effect of gases in the atmosphere would keep the ground at roughly 333 K (60 °C; 140 °F). However, when air gets hot or humid, its density decreases. Thus, air which has been heated by the surface tends to rise and carry internal energy upward, especially if the air has been moistened by evaporation from water surfaces. This is the process of convection . Vertical convective motion stops when

4365-416: The saturated adiabatic lapse rate (SALR) or moist adiabatic lapse rate (MALR) is given by: where: The SALR or MALR ( Γ w {\displaystyle \Gamma _{\text{w}}} ) is the temperature gradient experienced in an ascending or descending packet of air that is saturated with water vapor, i.e., with 100% relative humidity. The varying environmental lapse rates throughout

4462-550: The terrestrial ecoregions , there is a specific EcoID, format XXnnNN (XX is the biogeographic realm , nn is the biome number, NN is the individual number). The applicability of the realms scheme above - based on Udvardy (1975)—to most freshwater taxa is unresolved. According to the WWF, the following are classified as freshwater biomes: Biomes of the coastal and continental shelf areas ( neritic zone ): Example: Pruvot (1896) zones or "systems": Longhurst (1998) biomes : Other marine habitat types (not covered yet by

4559-406: The tropopause and into the stratosphere. Energy transport in the atmosphere is more complex than the interaction between radiation and dry convection. The water cycle (including evaporation , condensation , precipitation ) transports latent heat and affects atmospheric humidity levels, significantly influencing the temperature profile, as described below. The following calculations derive

4656-434: The tropopause , convection does not occur and all cooling is radiative. Within the troposphere , the lapse rate is a essentially the consequence of a balance between (a) radiative cooling of the air, which by itself would lead to a high lapse rate; and (b) convection, which is activated when the lapse rate exceeds a critical value; convection stabilizes the environmental lapse rate and prevents it from substantially exceeding

4753-420: The "morphoclimatic and phytogeographical domain" of Ab'Sáber , a geographic space with subcontinental dimensions, with the predominance of similar geomorphologic and climatic characteristics, and of a certain vegetation form. Both include many biomes in fact. To divide the world into a few ecological zones is difficult, notably because of the small-scale variations that exist everywhere on earth and because of

4850-512: The Chaco low attracts air masses from the South Pacific high, creating a dry and cold wind. This effect is more prominent in the winter months, when the intensity of the cold is more stronger. The Intertropical Convergence Zone reaches the region during the summer months, leading to low pressure, and unstable air masses due to the relatively high land temperatures compared to the sea during this season. This leads to enhanced precipitation in

4947-441: The Earth make up the biosphere . The term was suggested in 1916 by Clements , originally as a synonym for biotic community of Möbius (1877). Later, it gained its current definition, based on earlier concepts of phytophysiognomy , formation and vegetation (used in opposition to flora ), with the inclusion of the animal element and the exclusion of the taxonomic element of species composition . In 1935, Tansley added

SECTION 50

#1732764828242

5044-473: The Earth's atmosphere are of critical importance in meteorology , particularly within the troposphere . They are used to determine if the parcel of rising air will rise high enough for its water to condense to form clouds , and, having formed clouds, whether the air will continue to rise and form bigger shower clouds, and whether these clouds will get even bigger and form cumulonimbus clouds (thunder clouds). As unsaturated air rises, its temperature drops at

5141-643: The Global 200/WWF scheme): Humans have altered global patterns of biodiversity and ecosystem processes. As a result, vegetation forms predicted by conventional biome systems can no longer be observed across much of Earth's land surface as they have been replaced by crop and rangelands or cities. Anthropogenic biomes provide an alternative view of the terrestrial biosphere based on global patterns of sustained direct human interaction with ecosystems, including agriculture , human settlements , urbanization , forestry and other uses of land . Anthropogenic biomes offer

5238-403: The LCL by multiplying the difference by 125 m/°C. If the environmental lapse rate is less than the moist adiabatic lapse rate, the air is absolutely stable — rising air will cool faster than the surrounding air and lose buoyancy . This often happens in the early morning, when the air near the ground has cooled overnight. Cloud formation in stable air is unlikely. If the environmental lapse rate

5335-487: The Pacific Ocean along with atmospheric circulation patterns unfavourable for rain, this results in a dry season during winter. At the highest elevations, westerly winds from the Pacific Ocean can penetrate during the winter months, leading to snowstorms. Precipitation in the region is highly seasonal and is mostly concentrated in the summer months, during which precipitation decreases from east to west. Precipitation

5432-472: The Puna region can reach up to 30 °C (86.0 °F) while absolute minimum temperatures can fall below −20 °C (−4.0 °F). In Tucumán Province , the eastern parts have an average annual temperature of 18 to 20 °C (64.4 to 68.0 °F). Summers are hot with mean temperatures averaging between 24 and 26 °C (75.2 and 78.8 °F) while in winter, the mean temperatures are between 10 and 12 °C (50.0 and 53.6 °F). Easternmost parts of

5529-468: The Quebrada de Humahuaca valley ranges from 12.0 to 14.1 °C (53.6 to 57.4 °F), depending on elevation. In the Calchaquí Valleys in Salta province, the climate is similar to the valleys in La Rioja province and Catamarca province, by being temperate and arid with large thermal amplitudes, long summers, and a long frost free period which varies depending on elevation. Mean temperatures in

5626-407: The adiabatic lapse rate decreases to the moist adiabatic lapse rate as the air continues to rise. Condensation is also commonly followed by precipitation on the top and windward sides of the mountain. As the air descends on the leeward side, it is warmed by adiabatic compression at the dry adiabatic lapse rate. Thus, the foehn wind at a certain altitude is warmer than the corresponding altitude on

5723-477: The adiabatic lapse rate. Sunlight hits the surface of the earth (land and sea) and heats them. The warm surface heats the air above it. In addition, nearly a third of absorbed sunlight is absorbed within the atmosphere, heating the atmosphere directly. Thermal conduction helps transfer heat from the surface to the air; this conduction occurs within the few millimeters of air closest to the surface. However, above that thin interface layer, thermal conduction plays

5820-536: The afternoon mainly over land masses. In these conditions, the likelihood of cumulus clouds , showers or even thunderstorms is increased. Meteorologists use radiosondes to measure the environmental lapse rate and compare it to the predicted adiabatic lapse rate to forecast the likelihood that air will rise. Charts of the environmental lapse rate are known as thermodynamic diagrams , examples of which include Skew-T log-P diagrams and tephigrams . (See also Thermals ). The difference in moist adiabatic lapse rate and

5917-400: The area, the culture is also of great interest. It is strongly influenced by Quechua and Aymara cultures, and the region is quite distinct from the more European Buenos Aires . This influence can be seen in the music , clothing and customs of the people. 26°S 66°W  /  26°S 66°W  / -26; -66 Biomes A biome ( / ˈ b aɪ . oʊ m / )

SECTION 60

#1732764828242

6014-567: The arid climate. For example, in La Rioja Province , mean annual precipitation ranges from 300 mm (12 in) in the easternmost parts to 100 mm (3.9 in) at the foot of the Andes. Similarly in Catamarca Province , the mean annual precipitation varies from 150 mm (5.9 in) in the middle of valleys between the Andes mountains to more than 300 mm (12 in) in the nearby mountain ranges which form

6111-418: The atmosphere without exchanging energy with surrounding air) is 9.8 °C/km (5.4 °F per 1,000 ft). The saturated adiabatic lapse rate (SALR), or moist adiabatic lapse rate (MALR), is the decrease in temperature of a parcel of water-saturated air that rises in the atmosphere. It varies with the temperature and pressure of the parcel and is often in the range 3.6 to 9.2 °C/km (2 to 5 °F/1000 ft ), as obtained from

6208-478: The climatic and soil aspects to the idea, calling it ecosystem . The International Biological Program (1964–74) projects popularized the concept of biome. However, in some contexts, the term biome is used in a different manner. In German literature, particularly in the Walter terminology, the term is used similarly as biotope (a concrete geographical unit), while the biome definition used in this article

6305-401: The discovery of 12 graves dated to 6,000-1,300 years ago. Researchers also revealed necklaces and pendants next to some of the bodies. According to archaeologist Leticia Cortés, there were many kinds of burial methods, in individual or collective graves, and also in the posture of the bodies. Some were hyperflexed, like squatting, with the shoulders touching the knees. Northwest Argentina

6402-453: The dry adiabatic rate. The dew point also drops (as a result of decreasing air pressure) but much more slowly, typically about 2 °C per 1,000 m. If unsaturated air rises far enough, eventually its temperature will reach its dew point , and condensation will begin to form. This altitude is known as the lifting condensation level (LCL) when mechanical lift is present and the convective condensation level (CCL) when mechanical lift

6499-412: The dry rate is the cause of foehn wind phenomenon (also known as " Chinook winds " in parts of North America). The phenomenon exists because warm moist air rises through orographic lifting up and over the top of a mountain range or large mountain. The temperature decreases with the dry adiabatic lapse rate, until it hits the dew point, where water vapor in the air begins to condense. Above that altitude,

6596-466: The eastern parts of the region. Under the Köppen climate classification , the region has 5 different climate types which are semi–arid ( BS ), arid ( BW ), temperate climate without a dry season and with a dry season ( Cf and CW respectively) and an alpine climate at the highest elevations. The atmospheric circulation is controlled by the two semi–permanent South Atlantic and South Pacific highs, and

6693-495: The exception of the "Altos Hornos Zapla" steel furnace . Mining includes lithium , lead , silver , zinc and salt , and hydrocarbons extraction. The Argentine Northwest is a popular destination for both domestic and international travelers, attracting neighboring Argentinos and vacationing Europeans alike. Some of the most popular destination are Quebrada de Humahuaca and the Cerro de los Siete Colores , Cafayate and

6790-500: The form of convective thunderstorms during the summer months. During the winter months, the Intertropical Convergence Zone moves northwards to Ecuador while both the South Pacific and South Atlantic high move northwards, and the Chaco low weakens, all of which result in the suppression of rain during the winter. With the predominant wind being from the west and the Andes blocking most rain bearing clouds from

6887-401: The gradual changeover from one biome to the other. Their boundaries must therefore be drawn arbitrarily and their characterization made according to the average conditions that predominate in them. A 1978 study on North American grasslands found a positive logistic correlation between evapotranspiration in mm/yr and above-ground net primary production in g/m /yr. The general results from

6984-461: The higher elevations is between 12 and 14 °C (53.6 and 57.2 °F) at an elevation of 2,500 metres (8,202.1 ft) above sea level. Within the valleys located between the mountains, temperatures are cooler with a mean annual temperature of 13.1 °C (55.6 °F) (summers average 17.1 °C (62.8 °F) while winters average 9.0 °C (48.2 °F)) in the Tafi valley. The majority of

7081-507: The land to cool and temperatures to fall down. Mean temperatures in the warmest month in the Quebrada de Humahuaca valley range from 15.1 °C (59.2 °F) in Humahuaca at the higher elevations to 18.5 °C (65.3 °F) in Volcan at the lower elevations; in the coldest month, the mean temperature ranges from 7.1 to 8.1 °C (44.8 to 46.6 °F). The mean annual temperatures in

7178-469: The moisture comes from the east since the Andes block any moisture from the Pacific Ocean. Cold fronts that travel northwards to the region can produce precipitation during the summer months and is more prominent in the southern parts of the region. For example, in Tucumán Province , these cold fronts are responsible for 70% of the rainfall in that province. In contrast, during the winter months,

7275-478: The moisture currently located in forest biomes will dry up. Lapse rate The lapse rate is the rate at which an atmospheric variable, normally temperature in Earth's atmosphere , falls with altitude . Lapse rate arises from the word lapse (in its "becoming less" sense, not its "interruption" sense). In dry air, the adiabatic lapse rate (i.e., decrease in temperature of a parcel of air that rises in

7372-469: The mountain ranges are oriented in a north–south direction, increase in elevation to the west, and have a discontinuous orography , this allows valleys to have regions of relatively high precipitation in the west and drier regions in eastern parts of the valleys through orographic precipitation. In the temperate valleys, which include major cities such as Salta and Jujuy, average precipitation ranges from 500 to 1,000 mm (20 to 39 in). For example, in

7469-417: The point where it is equal to the actual vapor pressure of water. With further decrease in temperature the water vapor in excess of the equilibrium amount condenses, forming cloud , and releasing heat (latent heat of condensation). Before saturation, the rising air follows the dry adiabatic lapse rate. After saturation, the rising air follows the moist (or wet ) adiabatic lapse rate. The release of latent heat

7566-460: The population—and thus economic activity—of this region is concentrated in the many fertile valleys. In these valleys, the cultivation of sugarcane , tobacco , and citrus is the most important activity, along with cattle and goat raising. Important vineyards are also found in the Valles Calchaquíes in the Cafayate region. Thus most economic activity is associated with agriculture, with

7663-410: The potential to greatly alter the distribution of Earth's biomes. Meaning, biomes around the world could change so much that they would be at risk of becoming new biomes entirely. More specifically, between 54% and 22% of global land area will experience climates that correspond to other biomes. 3.6% of land area will experience climates that are completely new or unusual. An example of a biome shift

7760-465: The precipitation falls in the summer in the form of rain. The southeast part of the Puna region is very arid and receives the lowest annual precipitation in the region, averaging 50 mm (2.0 in). In the northeast part of the Puna region in Jujuy Province , mean annual precipitation ranges from 300 to 400 mm (12 to 16 in). Due to the aridity of these mountains at high elevations,

7857-527: The province, which borders the Chaco region are home to the highest and lowest temperatures in the province where absolute maximum temperatures can exceed 40 °C (104.0 °F) while absolute minimum temperatures can reach close to −7 °C (19.4 °F) owing to the accumulation of cold air that descends from the mountains. At higher elevations, the climate is cooler with summer temperatures averaging 20 °C (68.0 °F) and winter temperatures averaging 10 °C (50.0 °F). The annual temperature in

7954-413: The same thing, just that the lapse rate is a prerequisite for the greenhouse effect. The presence of greenhouse gases on a planet causes radiative cooling of the air, which leads to the formation of a non-zero lapse rate. So, the presence of greenhouse gases leads to there being a greenhouse effect at a global level. However, this need not be the case at a localized level. The localized greenhouse effect

8051-418: The seasonality of temperature and precipitation. The system, also assessing precipitation and temperature, finds nine major biome types, with the important climate traits and vegetation types . The boundaries of each biome correlate to the conditions of moisture and cold stress that are strong determinants of plant form, and therefore the vegetation that defines the region. Extreme conditions, such as flooding in

8148-448: The snowline can extend as far up as 6,000 m above sea level. The El Niño Southern Oscillation influences precipitation levels in northwest Argentina. During an El Niño year, the westerly flow is strengthened while moisture content from the east is reduced, resulting in a drier rainy season. In contrast, during a La Niña year, there is enhanced easterly moisture transport, resulting in a more intense rainy season. Nonetheless, this trend

8245-415: The south, the orographic effect is enhanced by advancing cold fronts from the south, resulting in enhanced precipitation. The high rainfall on these first slopes creates a thick jungle that extends in a narrow strip along these ranges. Beyond the first slopes of the Andes into the valleys, the air descends vertically, warming adiabatically, creating air that is drier and warmer than on the eastern slopes. Since

8342-494: The study were that precipitation and water use led to above-ground primary production, while solar irradiation and temperature lead to below-ground primary production (roots), and temperature and water lead to cool and warm season growth habit. These findings help explain the categories used in Holdridge's bioclassification scheme (see below), which were then later simplified by Whittaker. The number of classification schemes and

8439-492: The summer are very high, with a mean temperature of 26 °C (78.8 °F) in January, the warmest month. Temperatures can exceed 40 °C (104.0 °F) on an average of 20–25 days and can occasionally exceed 45 °C (113.0 °F), particularly in the central valley of Catamarca (Valle Central de Catamarca) and the valley of La Rioja Capital which lie at lower elevations than other valleys such as Tinogasta . Winters in

8536-697: The summer months and falls in short but heavy bursts. Valleys in the southern parts of the region are drier than northern valleys due to the mountains on the eastern slopes of both the Andes and the Sierras Pampeanas being taller than the ones in the north (ranging from 3,000 to 6,900 m (9,800 to 22,600 ft)), presenting a significant orographic barrier that blocks moist winds from the Atlantic and Pacific oceans. These valleys often receive less than 200 mm (7.9 in) of precipitation per year and are characterized by sparse vegetation adapted to

8633-405: The system to include the rest of North America in 1981, and the world in 1989. The Bailey system, based on climate, is divided into four domains (polar, humid temperate, dry, and humid tropical), with further divisions based on other climate characteristics (subarctic, warm temperate, hot temperate, and subtropical; marine and continental; lowland and mountain). A team of biologists convened by

8730-587: The temperature as a function of altitude for a packet of air which is ascending or descending without exchanging heat with its environment. Thermodynamics defines an adiabatic process as: the first law of thermodynamics can be written as Also, since the density ρ = m / V {\displaystyle \rho =m/V} and γ = c p / c v {\displaystyle \gamma =c_{\text{p}}/c_{\text{v}}} , we can show that: where c p {\displaystyle c_{\text{p}}}

8827-457: The temperature of the actual atmosphere does not always fall at a uniform rate with height. For example, there can be an inversion layer in which the temperature increases with altitude. The temperature profile of the atmosphere is a result of the interaction between radiative heating from sunlight , cooling to space via thermal radiation , and upward heat transport via natural convection (which carries hot air and latent heat upward). Above

8924-485: The types of vegetation found in a habitat. Holdridge uses the four axes to define 30 so-called "humidity provinces", which are clearly visible in his diagram. While this scheme largely ignores soil and sun exposure, Holdridge acknowledged that these were important. The principal biome-types by Allee (1949): The principal biomes of the world by Kendeigh (1961): Whittaker classified biomes using two abiotic factors: precipitation and temperature. His scheme can be seen as

9021-422: The valleys of La Rioja province and Catamarca province along with southwest Santiago del Estero province are mild, with a mean temperature of 12 °C (53.6 °F). Cold fronts from the south, bringing cold Antarctic air can cause severe frosts in the valleys of La Rioja province and Catamarca province. Temperatures can fall between −8 and −14 °C (17.6 and 6.8 °F) during these cold fronts. In contrast,

9118-464: The valleys. In Jujuy province, precipitation in the dry Quebrada de Humahuaca valley ranges from 200 to 410 mm (7.9 to 16.1 in). A similar annual precipitation is found in the dry Calchaquí Valleys , with mean annual precipitation ranging from 95 mm (3.7 in) in Molinos to 200 mm (7.9 in) in Cafayate . Further west in the Puna region next to Bolivia, the average elevation

9215-480: The variety of determinants used in those schemes, however, should be taken as strong indicators that biomes do not fit perfectly into the classification schemes created. In 1947, the American botanist and climatologist Leslie Holdridge classified climates based on the biological effects of temperature and rainfall on vegetation under the assumption that these two abiotic factors are the largest determinants of

9312-618: The warmest month in the Calchaqui valleys range from 14.5 °C (58.1 °F) at the higher elevations to 22.1 °C (71.8 °F) at lower elevations; in the coldest month, the mean temperature ranges from 4.8 to 9.6 °C (40.6 to 49.3 °F). The mean annual temperatures in the Calchaqui valleys ranges from 10.2 °C (50.4 °F) in La Poma at the higher elevations to 16.9 °C (62.4 °F) in San Carlos which lies at

9409-420: The windward side of the mountain range. In addition, because the air has lost much of its original water vapor content, the descending air creates an arid region on the leeward side of the mountain. If the environmental lapse rate was zero, so that the atmosphere was the same temperature at all elevations, then there would be no greenhouse effect . This doesn't mean the lapse rate and the greenhouse effect are

#241758