January 15, 2007
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Weather to go
Medio millón de personas fueron afectadas por lluvias en todo el Perú [ Translate this page ] El Comercio Peru 25/2/2008.
www.elcomercio.com.pe/.../HTML/2008-02-25/medio-millon-personas-fueron-afectadas-lluvias-todo-pais.html - 21k - Más/More www.google.com.pe/search?sourceid=navclient&ie=UTF-8&rlz=1T4GGLR_enPE264&q=Medio+mill%C3%B3n+de+peruanos+afectados+por+las+lluvias
http://image.weather.com/images/sat/sasat_440x297.jpgClick on: El clima en Peru. for past actuals of temperature and rainfall in cities all over Peru...
www.met.igp.gob.pe/cpntc/pronosticos/ciudades.html gives today's forecast in Spanish.
www.weatherbase.com/weather/city.php3?c=PE&refer= gives monthly temperatures & rainfall in English.
The anticipated El Niño effect of 2006/7 was modified by the arrival of cold water from melting Antartic ice, which has made it 2-3ºC colder than usual, with near 100% humidity. Trujillo is autumnal in the morning & Spring-like in the afternoons (5/10/2007).
National Geographic Magazine Article: El Nino/La Nina--Part 1 1997/8
National Geographic explores two of nature's most powerful weather ... that after weeks of incessant rain the adjacent Piura River had not stopped rising. ...
www.nationalgeographic.com/elnino/mainpage.html - 23k - Cached - Similar pagesNormal years' weather forecast:
Trujillo today will be warm, dry & sunny. The average annual temperature is 24ºC. We receive 7 hours per day of sunshine in Summer, 5 hours in Winter, & we are 15 minutes from the beach.
Trujillo has an early morning mist (much less frequent than Lima) which usually burns off fairly early. There are only about 20 days annually when the sun does not really get out, spread over July & August. The temperature never goes below 15ºC, & rarely exceeds 30ºC. a cool breeze blows, making it fresh, but be careful of the Sun, which can burn you even through the mist. For photography & comfort we arrange our tours to take advantage of the best sunlight, its angles & the clearest time of day, while avoiding excessive exposure. Every 3 to 8 years, we have an ''El Niño'' phenomenon. Today we know that if the Pacific Ocean here is 4ºC warmer than usual by August, we will have rains & floods from around December.
BBC - Weather Centre - 5 Day Forecast in Fahrenheit for Salaverry ... The BBC Weather five day forecast for your selected town or city, showing the temperature in Fahrenheit. Cached - Similar pages
www.bbc.co.uk/weather/5day_f.shtml?world=7265 - 42k -http://www.weather.com/ Search for the city of your choice.
A Sea Change around Chimbote - [ Traduzca esta página ]
Sandweiss, a University of Maine associate professor of anthropology and Quaternary and climate studies, first conducted research on clams as a Yale ...
www.climatechange.umaine.edu/ Research/news/seachange.html - 26k - En caché - Páginas similaresQuipu is a San Diego State University page for Andean Researchers. http://infodome.sdsu.edu/research/guides/quipu/webresources.shtml
A global warning On youtube
http://www.ministryofsound.com.au/ecard/prydz/A-Global-Warning.html
El NIÑO
THE PACIFIC OCEAN'S CIRCULATION
The Pacific Ocean is a huge mass of water that controls many climate features in its region. Its equatorial expanse is critical to the development of the Southern Oscillation and El Niño. In most years the Humboldt Current brings relatively cold water northward along the West Coast of South America, an effect increased by upwelling of cold water along the Peruvian Coast. The cold water then flows westward along the equator. These normal conditions make the western Pacific about 3°C to 8°C warmer than the eastern Pacific. However, in El Niño years the central or eastern Pacific may become as warm as the western Pacific.
THE WALKER CIRCULATION
The Walker circulation is named after Sir Gilbert Walker who, early this century, identified a number of relationships between seasonal climate variations in Asia and the Pacific region. The easterly trade winds are part of the low-level component of the Walker circulation. Typically, the trades bring warm moist air towards the Indonesian region. Here, moving over normally very warm seas, moist air rises to high levels of the atmosphere. The air then travels eastward before sinking over the eastern Pacific Ocean. The rising air is associated with a region of low air pressure, towering cumulonimbus clouds and rain. High pressure and dry conditions accompany the sinking air.
WHAT IS THE SOUTHERN OSCILLATION?
In 1924 Sir Gilbert T. Walker, a Director-General of British weather observation in India defined the Southern Oscillation as the tendency of pressure at stations in the Pacific to increase, while pressure in the region of the Indian Ocean decreases. This definition remains valid today and we now say that the Southern Oscillation occurs because of the large changes in the Walker circulation which are closely linked to the pattern of tropical Pacific sea temperatures. The Southern Oscillation Index (SOI) gives us a simple measure of the strength and phase of the Southern Oscillation, and indicates the status of the Walker circulation.
THE SOUTHERN OSCILLATION INDEX (SOI)
The SOI is calculated from the differences in the air pressure between Tahiti and Darwin. When the Walker circulation is strong the SOI is strongly positive. In its El Niño phase the Walker circulation is weak and the SOI is strongly negative. A positive SOI is associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Together these give a high probability that eastern and northern Australia will be wetter than normal. In an El Niño episode seas around Australia cool, and trade winds slacken. There is then a high probability that eastern and northern Australia will be drier than normal.
THE SOUTHERN OSCILLATION
Fluctuations in our climate are generally connected with the phenomenon called the Southern Oscillation, a major air pressure shift between the Asian and east Pacific regions whose best known extremes are El Niño events. The Southern Oscillation (strength and direction) is measured by a simple index, the SOI. The SOI is calculated from the monthly or seasonal fluctuations in the air pressure difference between Tahiti and Darwin. Positive values of the SOI are associated with stronger pacific trade winds and warmer sea temperatures to the north of Australia. Together these give a high probability that eastern and northern Australia will be wetter than normal.
EL NIÑO
Drought, an inevitable part of the normal variability of climate, is experienced in varying degrees in all regions, which ordinarily have sufficient rain for agriculture and water supply. The most significant recurring climatic anomaly is associated with the El Niño phenomenon, an anomalous warming of the central and eastern tropical Pacific Ocean. The irregular pattern of warming and cooling of the ocean surface layer is linked to fluctuations in the pressure differences and wind fields across the Pacific Ocean, the Southern Oscillation. Many severe Australian droughts have been associated with El Niño. The Bureau's National Climate Centre monitors the global climate and uses computer models to help it predict times of rainfall deficiencies.
EL NIÑO'S GLOBAL EFFECTS
The El Niño current is caused by large scale interactions between the ocean and the atmosphere. Nowadays, the term El Niño refers to changes in circulations across the Pacific Ocean and the Indonesian archipelago when warming of the ocean in the eastern Pacific is particularly strong. This occurs, on average, every three to eight years. Characteristic changes in the atmosphere accompany those in the ocean resulting in altered weather patterns across the globe. During El Niño events rainfall deficiencies often occur in eastern Australia the islands to its north, in eastern Africa and in Brazil. Higher temperatures occur in China, Japan, Alaska and parts of Canada.
CLIMATE CLUES TO EL NIÑO
Meteorologists watch for changes to the atmosphere and ocean circulation, which help them detect an El Niño event, or forecast its lifetime. During El Niño the Pacific trade winds weaken and in the more intense episodes, westerly winds are observed over parts of the equatorial western and central Pacific. The area of warm water usually over the western tropical Pacific cools and the warmer water is displaced eastward to the central Pacific. The normally cold waters on the South American coast warm by 2°C to 8°C. The Southern Oscillation Index remains negative and enhanced cloudiness develops over the central equatorial Pacific.
WHY 'EL NIÑO'?
El Niño translates from Spanish as 'the boy-child'. Peruvian anchovy fishermen traditionally used the term, a reference to the Christ child, to describe the appearance, around Christmas, of a warm ocean current off the South American coast, adjacent to Ecuador and extending into Peruvian waters. El Niño affects traditional fisheries in Peru and Ecuador. In most years, colder nutrient-rich water from the deeper ocean is drawn to the surface near the coast (upwelling), producing abundant plankton, the food source for the anchovy. In El Niño years, when upwelling weakens, and warmer low-nutrient water spreads along the coast, the anchovy harvest plummets.
THE EFFECTS OF EL NIÑO
Rural productivity, especially in Queensland and New South Wales, and to a lesser extent in southeastern Australia, is linked to the behavior of the Southern Oscillation, Australia's wheat yield has fluctuated with variations in the Southern Oscillation. Negative phases in the oscillation (drier periods) tend to have been linked with reduced wheat crops, and vice versa. Tourism is another industry vulnerable to large swings in seasonal climate. Because climate variability can affect the Australian economy, Australians need the best possible understanding of the physical mechanisms controlling this dramatic feature of their climate.
EL NIÑO'S GLOBAL EFFECTS
The El Niño current is caused by large scale interactions between the ocean and the atmosphere. Nowadays, the term El Niño refers to changes in circulations across the Pacific Ocean and the Indonesian archipelago when warming of the ocean in the eastern Pacific is particularly strong. This occurs, on average, every three to eight years. Characteristic changes in the atmosphere accompany those in the ocean resulting in altered weather patterns across the globe. During El Niño events rainfall deficiencies often occur in eastern Australia, the islands to its north, in eastern Africa and in Brazil. Higher temperatures occur in China, Japan, Alaska and parts of Canada.
EL NIÑO'S OPPOSITE PHASE
Much of eastern Australia is currently experiencing the effects of a strong El Niño episode and widespread rainfall deficiencies. When the Southern Oscillation Index swings from high negative values and sustains high positive values, the Walker circulation intensifies, and the eastern Pacific Ocean cools. This results in an increase in atmospheric moisture over northern Australia and these changes often bring widespread rain and flooding to Australia. This phase is sometimes called anti-El Niño, or La Nina. Australia's strongest recent examples were in 1973-74 and 1988-89. Brisbane's worst flooding this century occurred in January 1974 and vast areas of inland Australia had record rainfall in March 1989.
CLIMATE CLUES TO EL NIÑO
Meteorologists watch for changes to the atmosphere and ocean circulation, which help them detect an El Niño, or forecast its lifetime. Indicators are: The Walker circulation and trade winds weaken. During more intense El Niño episodes, westerly winds are observed over parts of the equatorial western and central Pacific. The area of warm water usually over the western tropical Pacific cools and the warmest water is displaced eastward to the central Pacific. The normally cold waters on the South American coast warm by 2°C to 8°C. The Southern Oscillation Index remains negative. Enhanced cloudiness develops over the central equatorial Pacific.
EL NIÑO & PERU
Most Australians are familiar with the affect El Niño has on Australia. El Niño’s have been affecting the cultures of the West Coast of South America for centuries. The cold Humboldt current which travels along the West Coast of South America keeps water temperatures approximately 7°C cooler than what would be expected. Predominant westerly winds cross this stretch water, as the water is cool there is little evaporation so the air reaching the coast is dry. Some locations have no appreciable rainfall for several years. The average rainfall of Trujillo is 4.8 mm per year.
EL NIÑO & PERU 2
In an El Niño year the water off the coast of Peru warms up and the usually dry winds pick up the moisture and head inland where rain will fall. In Trujillo with an annual average rainfall of 4.8 mm per year there have been individual months during an El Niño where over 300 mm has fallen. The floods associated with the 1998 El Niño destroyed many of the bridges of the Pan American Highway in Northern Peru. The main building materials are mud bricks, these bricks do not stand up to torrential rain and many were left homeless.
ARCHAEOLOGY PERU & EL NIÑO
There are numerous spectacular archeological ruins along the coast of Peru with many being made of mud bricks. Two huge structures the temple of the sun and the moons are located near Trujillo. These structures were built by the Moche people. The Moche people occupied a dozen valleys of the North Peruvian desert coast between 200 BC and 750AD. They constructed canals up to 113 kilometres long, navigable 90 kilometres inland, & farmed areas 50% larger than today. The temples were the largest man made constructions in South America until recent times. The Sun was 300 metres long and 45 metres high and made up of 140 million adobe bricks. Rainfall during an El Niño washed a third of the structure away.
THE MOCHE PEOPLE & EL NIÑO
The Moche had adapted well to their "dry" climate with their system of irrigation canals. During El Niño’s however the rainfall caused such problems that it was thought to be the god’s displeasure. The temple of the moon is built on the side of a mountain. Below a black outcrop at the base of the mountain, an archaeologist found 42 human sacrifices, in what had once been thick mud. It is believed that they were sacrificed, offered to the Gods, so that it would stop raining. Four earlier sacrifices lower down indicated that sacrifice was habitual and others on top of the mud are thought to be to say ‘Thank God it has stopped raining’.
THE MOCHE PEOPLE & EL NIÑO 2
The sacrifices to "stop" the rain were healthy prisoners between 15 & 35 years old, sacrificed with war clubs, ceremonial tumi knifes, strangling or throat cutting, stretched out and beaten into thick mud. Some had suffered previous injuries, which had healed, such as broken left arms, from shielding themselves, broken legs or fractured skulls, considered to be ‘professional injuries’ from the battle they were captured in. Some suffered broken noses or cracked ribs, which were healing between 2 to 5 weeks before death, presumably from being injured, captured, held prisoner that period and then being sacrificed. Andean peoples believe the land will be productive without their ritual offerings, the ultimate of these offerings; a human life.
THE MOCHE PEOPLE & EL NIÑO 3
It is likely that El Niño played a large part in the ending of the Moche civilisation. In 560AD an extreme ‘El Niño’ followed a big earthquake, and preceded a 30 year drought (562-594ad according to glacier ice core samples). That ‘El Niño’ may have destroyed the canals, the crops & homes, brought diseases, washed away the rich alluvial soil of the valley, into the Ocean. The nutrient rich ocean contains phytoplankton, zooplankton, anchovies & over 300 other species of fish & some of the world’s densest seabird populations. The runoff with the silt may have damaged the fishing, and returned onshore as sand dunes to repeatedly spoil the agriculture.
THE MOCHE PEOPLE & EL NIÑO 4
The El Niño events shook the society’s faith in their gods, leaders & culture. The elite abandoned the Moche Pyramids and everything south of them and moved inland to Galindo, with dividing walls in the city suggesting friction between the social classes. The town of Sipan was abandoned in favour of Pampa Grande, that inland site replacing Moche as their capital. Other cultures also suffered, in 1100AD (another large El Niño event) the Lambayeque culture blamed their king, Fempallec for a series of weather related disasters, and threw him to his death from a cliff.
PERUVIAN RUINS AND EL NIÑO AND PRESERVATION
Increased frequency and severity of El Niños in recent years have led to some sites being given protection from the rain. The temple of the sun has already decreased in size by up to one third due to the weathering affects of rainfall that only falls in El Niño years. In late 1997 with an El Niño predicted parts of The Temple of the Sun were covered to prevent further erosion. This was fortuitous, as the 1998 event was one of the strongest on record. This work was paid for by UNESO under the World Heritage program.
PERUVIAN RUINS AND EL NIÑO AND PRESERVATION 2
Another Peruvian archaeological site that is under threat from the ravages of El Niño are the famous Nazca Lines. The lines and pictures were created between 500BC and 500AD. With little or no rainfall in the area they have been preserved. During the 1998 El Niño rivers of mud from heavy rainfall higher in the Andes swept across Nazca plain damaging some of the hieroglyphics. The main (popular) pictures were left undamaged but with the possibility of global warming contributing to more frequent and severe El Niños protection work is necessary.
PERUVIAN RUINS AND EL NIÑO AND PRESERVATION 3
The ancient Mud City of Chan Chan once covered 28 square kilometres and was thought thought to have housed between 50,000 and 200,000 people. The city was built by the Chimu people who reigned from 700AD until the mid 1400s when they were conquered by the Incas. The city however, was not looted until the arrival of the Spanish. The city was damaged in the El Niño of 1100. El Niño rains now threaten the remnants of the city (still several square kilometres). Archaeologists are experimenting with different water-resistant solvents to protect the site from the El Niño rains.
HALO PHENOMENA
Occasionally a halo can be observed around the sun or moon. In this halo, if it is well developed, colours of the spectrum can be seen, with red on the inside. This is because halos are caused by the refraction of light through ice crystals, each behaving as a tiny prism, through a thin layer of high cloud. It always has a radius of 22 degrees from the sun or moon. In exceptional circumstances, a second, fainter halo is visible at a radius of 46 degrees. As a thin layer of high cloud sometimes precedes a front or low pressure system, folklore has it that a halo is a portent of bad weather.
On the principal Plaza of the Huaca Cao Viejo, at the El Brujo Complex, the Moche left 2 concentric circles, the largest over 5 metres in diameter, which are believed to represent this phenomenon. They are related to 2 straight lines heading due north, & not to other lines indicating where bricks should be laid. The lines are within 40 metres of friezes representing warriors, prisoners of war to be sacrificed, & their associated god, Ai Apaec.
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