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Foro general de Meteorología => Climatología => Mensaje iniciado por: Herminator en Viernes 23 Septiembre 2005 12:39:11 pm
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New Zealand glaciers growing - 30 August 2005 - The most recent survey of the 50 glaciers monitored annually by the National Institute of Water & Atmospheric Research (NIWA) was undertaken in March of this year. Dr Jim Salinger of NIWA said today that the glaciers in New Zealand’s Southern Alps had gained much more ice than they had lost during the past glacier year
This year’s gains are due to more snow in the Southern Alps , particularly from late
winter to early summer 2004. During this five month period, temperatures were 0.6°C below average, producing more snow.
"Over the last three years, the glaciers have gained in mass, halting the declines seen between 1998 and 2002. This past year was the seventh largest gain since we started aerial surveys in 1977," said Dr Salinger.
Es decir, de nuevo y por tercer año consecutivo, los glaciares de Nueva Zelanda ganan masa!!
Aquí el artículo enterito,...es super intersante!! 10000mm de precipitación nivosa en la divisoria de la cordillera :o :o :o :o
New Zealand glaciers continue to recover
30 August 2005
Glaciers in New Zealand’s Southern Alps gained ice mass again in the past year. Fifty glaciers are monitored annually by the National Institute of Water & Atmospheric Research (NIWA).
NIWA’s most recent survey of the glaciers was undertaken in March this year. Dr Jim Salinger of NIWA said today that analysis of the aerial photographs shows the glaciers had gained much more ice than they had lost during the past glacier year (March 2004 – February 2005).
This year’s gains are due to more snow in the Southern Alps, particularly from late winter to early summer 2004. During this five month period, more depressions ('lows') to the southeast of the Chatham Islands brought frequent episodes of strong cold southwesterly winds, and temperatures were 0.6°C below average, producing more snow.
"Over the last three years, the glaciers have gained in mass, halting the declines seen between 1998 and 2002. This past year was the seventh largest gain since we started aerial surveys in 1977," said Dr Salinger. "Since 1977 overall for the Southern Alps there has been little change in size of the glaciers."
"The recent gains do not compensate for the large overall losses seen over the past century. The iconic Franz Josef glacier is still much shorter now than in 1900, and the volume of ice in the Southern Alps dropped by about 25-30% last century. This is linked to an increase in regional mean temperatures of 0.7°C."
Globally, most glaciers are retreating as the Earth warms. Of the glaciers for which there are continuous data from the World Glacier Monitoring Service, the mean annual loss in ice thickness since 1980 remains close to half a metre per year. The Service has said that the loss in ice mass "leaves no doubt about the accelerating change in climatic conditions".
New Zealand’s glaciers are somewhat unusual because they have their source in areas of extremely high precipitation. West of the main divide in the Southern Alps, more than 10 metres (10 000 mm) of precipitation falls a year as clouds are pushed up over the sharply rising mountain ranges. This means the mass of New Zealand’s glaciers are sensitive to changing atmospheric circulation and both precipitation patterns and temperature. So, for instance, the glaciers advanced during most of the 1980s and 1990s when the area experienced about a 15% increase in precipitation, associated with more El Niño events. In most of the rest of the world (with the exception of parts of Norway), glaciers tend to be in areas of lower precipitation, so rising temperatures are affecting the glaciers there more directly and sooner.
Dr Salinger said the annual NIWA flights in March use a small fixed wing aircraft. They record the height of the glacial snow line at the end of summer. "This reveals how much snow the glaciers have lost or gained during the past year. The lower the snow line, the more the amount of snow that has accumulated to feed the glacier. On average, the snow line this year was about 110 metres below where it would be to keep the ice mass constant."
He said the level of the glacier snow lines is not closely related to the amount of snow that might fall on the country’s ski fields during winter. "Most of the popular ski fields are east of the Main Divide, or in the North Island. Mount Hutt, for instance, gets its snow from big southeasterlies, whereas most of the glaciers are fed by westerlies," Dr Salinger said.
For more information, contact:
Dr Jim Salinger
Principal Scientist
NIWA, Auckland
Phone +64-4 375 2053
Mobile +64-27 521 9468
[email protected]
World Glacier Monitoring Service: www.geo.unizh.ch/wgms
Background on recent controversy regarding the state of world's glaciers:
David Bellamy's incorrect claims:
Glaciers are cool, New Scientist, 16 April 2005
Subsequent developments as reported in New Scientist:
Glacial meltdown, New Scientist, 30 April 2005
British conservationist to lose posts after climate claims, New Scientist, 11 June 2005
Retired, not fired, New Scientist, 2 July 2005
George Monbiot, writing in The Guardian, tracks down the source of Bellamy's errors:
http://www.monbiot.com/archives/2005/05/10/junk-science/
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Joder si caen 10000 mm de nieve es como para haber glaciares casi hasta en Cuba.
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Vaya, tenía yo la duda de si el aumento de temperaturas en el hemisferio norte no se correspondería con un descenso en el hemisferio sur, y que después de tanta gaita lo único que hubiera pasado es un desplazamiento hacia el norte de los diferentes jets, celulas, etc.
Que pena que el hemisferio sur en sus latitudes medias tenga tanta agua.
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Que pena que el hemisferio sur en sus latitudes medias tenga tanta agua.
¿A qué te refieres con esto?
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Que pena que el hemisferio sur en sus latitudes medias tenga tanta agua.
¿A qué te refieres con esto?
Pues que logicamente no vive gente allí y no hay estaciones de superficie. En resumen cuantos datos para el norte, cuan pocos para el sur
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Pues si que es interesante, tendremos que estar atentos a otras noticias que salgan respecto a esto
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esto tiene una explicacion fisica , no es nada milagroso , si como se ha demostrado el NORTE ARTICO se esta deshielando , es logico , dado que existe una ley de compensacion entre ambAS antipodas qeu en el POLO SUR aumenten los glaciares , eso no hace mas que corroborar que el norte se deshiela para desgracia nuestra seguramente.no hay mas que ver la corriente del golf stream. por cierto hermineirtor no entiendo el ingles .... un saludo
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púes aquí lo voy a enlazar (es del new zeland herald)
es un artículo sobre la "asincronicidad" entre los glaciares del hemisferio sur y el norte,
NZ glacier findings upset climate theory (http://www.nzherald.co.nz/environment/news/article.cfm?c_id=39&objectid=10569888)
Research by three New Zealand scientists may have solved the mystery of why glaciers behave differently in the Northern and Southern Hemispheres.
Geologist David Barrell of GNS Science, Victoria University geomorphologist Andrew Mackintosh and glaciologist Trevor Chinn of the Alpine and Polar Processes Consultancy have helped provide definitive dating for changes in glacier behaviour.
They were part of a team of nine scientists, led by Joerg Schaefer of the Lamont-Doherty Earth Observatory at Columbia University in New York, who used an isotope-dating technique to get very precise ages for glacial deposits near Mt Cook.
They measured the build-up of beryllium-10 isotopes in surface rocks bombarded by cosmic rays to pinpoint dates when glaciers in the Southern Alps started to recede. The technology is expected to be widely applied to precisely date other glaciers around the world.
Glaciers are sensitive indicators of climate changes, usually advancing when it cools and retreating when it warms.
The first direct confirmation of differences in glacier behaviour between the Northern and Southern Hemispheres, the new work topples theories based on climate in the Northern Hemisphere changing in tandem with the climate in the Southern Hemisphere.
The research argues that at times the climate in both hemispheres evolved in sync and at other times it evolved differently in different parts of the world.
Dr Barrell said their research presented "new data of novel high precision", though the team has so far chosen not to roll out wider interpretations too quickly.
He said much of it reinforced work done 30 years ago by Canterbury University researcher Professor Colin Burrows, who used NZ glacier data to highlight some of the similarities and differences between northern and southern records over the past 12,000 years.
The paper published in Science magazine yesterday showed the Mt Cook glaciers advanced to their maximum length 6500 years ago, and have been smaller ever since.
But glaciers in the Swiss Alps advanced to their maximum only in the past 700 years - during the Northern Hemisphere's "Little Ice Age", which ended about 1860.
During some warm periods in Europe, glaciers were advancing in New Zealand. At other times, glaciers were well advanced in both areas.
In a commentary which accompanied the research, Greg Balco, from the Berkeley Geochronology Centre in California, said the conclusion that glacier advances in the Northern and Southern Hemispheres were not synchronised was "unexpected".
Dr Barrell said the paper presented only the first instalment of the dating work, and more would be revealed at an international workshop on past climates to be held at Te Papa on May 15.
"The New Zealand findings point to the importance of regional shifts in wind directions and sea surface temperatures," he said.
Regional weather patterns such as the El Nino Southern Oscillation were superimposed on the global climate trends reflected in the behaviour of glaciers.