CLIMATE CHANGE NOW- CAMBIO CLIMATICO AHORA: Punto caliente de seguimiento:

25/3/10

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Como consecuencia de la erupción del volcán Eyjafjallajokull en Islandia, habrá que hacer un seguimiento del comportamiento del monte Katla, que de hacer crisis y entrar también en erupción puede arrojar no solo las cenizas correspondientes en cantidades superiores a las de anterior, modificando las corrientes de aire, sino la aportación de enormes cantidades de agua dulce al Atlántico Norte con la posible afección a la Corriente Termohalina (THC) de la que depende en gran medida el clima del Norte de Europa y de Autralia, una por enfriamiento (EU) y otra por calentamiento (AU).

La erupción del Eyjafjallajokull se ha debido al parecer por el drenaje de un lago, posiblemente debido al calentamiento reciente de la zona y el deshielo consiguiente.¿Estaremos pronto ante un nuevo efecto como el producido por el lago glacial Agassiz en Norte America?

(Post: RG)

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TEMPORAL EN EUROPA 2012

1/02/2012. La ola de frío polar continental que afectará a partir de este jueves a España se produce aproximadamente una vez entre siete u ocho años y, de hecho, "esta podría ser de las cuatro más frías desde 1950", según la Agencia Estatal de Meteorología (AEMET).

MADRID, 1 (EUROPA PRESS)

Así, el portavoz de la AEMET, Ángel Rivera, ha explicado a Europa Press que esta situación "no es desconocida en invierno", pero ha añadido que, en este caso, además de las bajas temperaturas, la sensación térmica será de "aún más frío" debido a los vientos del nordeste de entre 30 y 40 kilómetros por hora y de hasta 70 u 80 kilómetros por hora en el cuadrante nordeste y Baleares.

En este contexto, ha precisado que el temporal consiste en un anticiclón que se extiende por el norte de Europa con un eje inclinado nordeste-suroeste y que lleva un borrasca fría al sur en torno al Mediterráneo y sur de Europa. Esto implicará una descarga de viento del nordeste que arrastra masas de aire que proceden de Rusia o el interior de Europa y, a veces, de la propia Siberia.

Según ha indicado, ese es el motivo por el que se conocen como "olas siberianas", aunque ha detallado que su nombre técnico es "aire polar continental", el cual se distingue del aire polar marítimo en que el segundo es menos frío y más húmedo, mientras que este es más frío y de carácter seco. "Esta tipo de masas de aire son las que más frío pueden traer a España", ha apuntado.

En este contexto, el portavoz de la AEMET ha apuntado que el inicio de esta ola viene precedido asimismo de una descarga de aire frío que recorrerá la Península "desde este jueves a mediodía, de nordeste a suroeste" y que, a su paso dejará precipitaciones de lluvia y sobre todo de nieve a partir de 400 o 500 metros de altura, aunque salvo en las cordilleras, las nieves no serán "muy importantes".

MÁS NIEVE EN ÁFRICA QUE EN ESPAÑA

Rivera ha advertido que a lo largo de este jueves esta masa de aire frío cubrirá toda España e incluso rebasará la Península y llegará al norte de África, donde destacará por las temperaturas mínimas en el norte de Argelia, Túnez o Libia que serán "significativas" y donde la nieve hará presencia, "de hecho de forma más destacable que en España".

En cuanto a la duración de la situación, el portavoz de la AEMET, considera que se prolongará el jueves, el viernes y el sábado y que comenzará a disminuir el domingo.

Así, ha adelantado que en España lo que pasará es que una corriente de vientos fuertes de unos 30 a 40 kilómetros por hora y que en la zona de Cataluña, Baleares y Aragón, la tramontana y el cierzo podrían llegar hasta los 70 u 80 kilómetros por hora.

De este modo, ha dicho que se espera que las temperaturas máximas sean "muy bajas" y que se queden entre los 0 y los cinco grados centígrados en buena parte de la península. Incluso en muchos sitios de Castilla y León, Navarra y el norte peninsular las máximas rondarán los cero grados.

En cuanto a las mínimas, prevé que los termómetros no suban de los -5 a -10 grados centígrados en la mayor parte de España, que lleguen a -14 grados centígrados en zonas de montaña e incluso hasta -20 grados centígrados en alta montaña. "Sin embargo, la sensación térmica será todavía más fría, debido a las fuertes rachas de viento polar", ha subrayado.

En cuanto a precipitaciones, ha avisado de que donde más nevará será en la costa de Cataluña, en la costa del país Vasco y unos kilómetros hacia el interior y, sobre todo serán más importantes en Baleares donde las precipitaciones serán sobre los 200 metros e incluso podría nevar en la costa.

A partir del domingo, la tendencia es que esta situación comience a disminuir por la mitad occidental peninsular, aunque la tendencia general apunta a que la situación comience a aminorar de virulencia y que las temperaturas empiecen a subir a partir del lunes en la mitad oeste peninsular. En cuanto a la mitad este y Baleares, la situación se prolongará hasta el martes. La estabilización o normalización en todas las zonas no llegará hasta el miércoles.

En general, las zonas más frías serán las situadas al norte de una línea imaginaria desde La Coruña a Almería. Esta entrada pueblos de España

ANTECEDENTES

Esta masa de aire es "bastante más fría que en otras ocasiones", ya que esta situación se afecta a España una vez cada siete u ocho años. En lo que va del siglo XXI se conocen dos situaciones similares, en diciembre de 2001 y en enero de 2005, aunque "esta las podría igualar o incluso superar".

Por otro lado, desde los años 50 del siglo pasado esta situación se ha producido entre siete u ocho ocasiones, la mayoría de ellas en las décadas de los 50, 60 y comienzos de los 70 y menos en los 80 y 90. La de esta ocasión se podría situar entre las cuatro más fuertes desde 1950. Es una situación bastante intensa, de bastante frío y no estamos acostumbrados a este tipo de entradas tan severas que no se estaban produciendo mucho.

La ola de frío "paradigmática" de este tipo se remonta a 1956, cuando España estuvo afectada del 1 al 20 de febrero y provocó graves daños a la agricultura y la industria. "Aquello fue un hito en la historia de España", ha concluido.

TIMING OF ABRUPT CLIMATE CHANGE - YOUNGER DRYAS

TIMING OF ABRUPT CLIMATE CHANGE AT THE END OF THE YOUNGER DRYAS INTERVAL FROM THERMALLY FRACTIONATED GASES IN POLAR ICE

Jeffrey P. Severinghaus*, Todd Sowers†, Edward J. Brook‡, Richard B. Alley† & Michael L. Bender*§

* Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island 02882, USA

† Geosciences Department, Pennsylvania State University, University Park, Pennsylvania 16802, USA

‡ Departments of Geology and Environmental Science, Washington State University, Vancouver, Washington 98686, USA

Rapid temperature change fractionates gas isotopes in unconsolidated snow, producing a signal that is preserved in trapped air bubbles as the snow forms ice. The fractionation of nitrogen and argon isotopes at the end of the younger Dryas cold interval, recorded in Greenland ice, demonstrates that warming at this time was abrupt...

http://homologa.ambiente.sp.gov.br/proclima/artigos_dissertacoes/dissertacoes_ingles/timingofabruptclimatechange.pdf

Climate Change and the Big Arctic Thaw Tweet. Share Email Wed, May 4, 2011 -- 9:00 AM

An alarming new report says climate change is happening in the Arctic at a more rapid pace than previously believed. Melting ice could elevate the global sea level by as much as five feet in this century. We talk with writer, environmentalist and climate change expert Tim Flannery about what this new information says about the future of our planet. Host: Michael Krasny Guests: Tim Flannery, Australia's chief commissioner for climate change, director of the Australian Wildlife Conservancy and author of "The Weather Makers" and the new book, "Here on Earth: A Natural History of the Planet" More info: About the book "Here on Earth: A Natural History of the Planet" : at Amazon.com

Probing a glacier as it thaws

BY LAUREN MORELLO, E&E REPORTER Third in a three-part series. KANGERLUSSUAQ, Greenland -- In her knitted ski hat, parka and hiking boots, Åsa Rennermalm doesn't look like an accountant -- or a plumber. But the Rutgers University hydrologist draws on both disciplines as she works at the southwestern edge of Greenland's vast ice sheet. She's spent the past four years trying to answer a deceptively simple question: When Greenland's ice melts, where does the water go? "Satellites show the surface of the ice is melting and the volume of ice is decreasing," Rennermalm says. "But how much meltwater is leaving and reaching the ocean? That will influence future sea level rise." She and colleagues from the University of California, Los Angeles, are studying the runoff from one chunk of the Greenland ice sheet -- Russell Glacier, which sits 16 miles outside of this small town. Because it rests entirely on land, it isn't vulnerable to the influxes of warming ocean water that cause outlet glaciers to calve. The main way Russell loses ice is surface melting. Some of the resulting water runs off the glacier into nearby lakes and streams. Some drains into cracks and channels in the ice, where it can refreeze or flow to subglacial streams and lakes that feed into the sea. The scientists are trying to track the water that runs off Russell Glacier and trace it back to its source.

INUNDACIONES UK

Inundación - Reino Unido Los equipos de rescate británicos trabajan a pleno rendimiento. Con helicópteros y botes hinchables, han logrado poner a salvo a decenas de personas atrapadas por la inundaciones que asolan el noroeste de Inglaterra y el sur de Escocia. Las fuertes lluvias registradas en las últimas horas han anegado centenares de viviendas, obligando a sus habitantes a refugiarse en centros especiales. La región más afectada es la de Cumbria, donde hay varios desaparecidos. En la localidad de Cockermouth, por ejemplo, el nivel de las aguas supera los dos metros y medio. La calle principal de esta localidad se ha convertido en un auténtico río. Las previsiones para este viernes no son nada halagüeñas. La agencia meteorológica británica habla de abundantes lluvias y fuertes vientos. Copyright © 2011 euronews

Nonnormal Amplification of the Thermohaline Circulation

Laure Zanna

Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts

Eli Tziperman

Division of Engineering and Applied Sciences, and Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts

Abstract

A simple zonally averaged coupled ocean–atmosphere model, with a relatively high resolution in the meridional direction, is used to examine physical mechanisms leading to transient amplification of thermohaline circulation (THC) anomalies. It is found that in a stable regime, in which small perturbations eventually decay, there are optimal initial conditions leading to a dramatic amplification of initial temperature and salinity anomalies in addition to the THC amplification. The maximum amplification occurs after about 40 years, and the eventual decay is on a centennial time scale. The initial temperature and salinity anomalies are considerably amplified by factors of a few hundreds and 20, respectively. The initial conditions leading to this amplification are characterized by mutually canceling initial temperature and salinity anomalies contributions to the THC anomaly, such that the initial THC anomaly vanishes. The mechanism of amplification is analyzed and found to be the result of an interaction between a few damped (oscillatory and nonoscillatory) modes with decay time scales lying in a range of 20–800 years. The amplification mechanism is also found to be distinct from the advective feedback leading to THC instabilities for large freshwater forcing.

Received: September 10, 2004; Accepted: March 1, 2005

Corresponding author address: Laure Zanna, Department of Earth and Planetary Sciences and Division of Engineering and Applied Sciences, Harvard University, Cambridge, MA 02138. zanna@fas.harvard.edu

http://journals.ametsoc.org/doi/full/10.1175/JPO2777.1

El papel de polvo en el cambio climático abrupto

El papel de polvo en el cambio climático abrupto: Claves desde las costas de África del Noroeste y de Alborán registros de sedimentos del Mar

Autores : A. Moreno, M. Canales

Contribuciones a la Ciencia, ISSN 1575-6343, Vol . 2 , N º. 4, 2004 , pags . 485-497
Los sedimentos marinos son uno de los mejores archivos de los cambios climáticos del pasado , ya que son esencialmente de carácter permanente y su edad se puede determinar con relativa facilidad. Durante las últimas décadas , muchos estudios paleoclimáticos han centrado en los cambios climáticos bruscos , que puedan ser utilizadas como modelos de los futuros cambios climáticos . Una de las preguntas clave que se plantea es el papel de la atmósfera en el desencadenamiento y la transferencia de los cambios bruscos del clima. En este sentido , la investigación de la influencia de las partículas de polvo eólico sobre el cambio climático merece una atención especial. El estudio de la acumulación de polvo eólico en los sedimentos marinos es crucial no sólo para entender el cambio climático pasado, sino también para explicar los mecanismos del cambio climático en general . En este artículo , las interacciones entre polvo en la atmósfera y el cambio climático rápido se discuten después de una revisión de los registros de sedimentos marinos , en las escalas temporales glaciales e interglaciales y milenario , desde la costa del noroeste de África y el Mar de Alborán .

Cambio de la temperatura del agua del Atlantico Norte 2008-2010

Teniendo en cuenta las condiciones de estabilidad de temperaturas del agua que necesita la corriente del Golfo es de considerar esta información. Hay una tendencia al enfriamiento de la temperatura del agua que rodea a las islas británicas y también en las áreas del Cantábrico. Si se compara la situación térmica entre el 10 de octubre del 2008 con la del 2006, hay lugares del mar de Irlanda en donde la temperatura descendió mas de 6º centigrados.
Se explica en las imágenes de Meteociel:

http://www.meteociel.com/accueil/sst.php

Informe sobre posibilidad de cambio de clíma súbito,del Departamento de Defensa de los EEUU, de 2003

Informe sobre la posibilidad de un cambio de clima súbito, que afectaría a todo el hemisferio Norte ( para una miniglaciación) y al hemisferio sur (calentamiento ecuatorial), para el Departamento de Defensa de los EEUU, de Peter Schwartz and Doug Randall, en octubre de 2003.

Report on the possibility of sudden climate change that would affect the whole northern hemisphere (for a miniglaciación) and the southern hemisphere (warm equatorial) for the Department of Defense U.S., Peter Schwartz and Doug Randall, October 2003.

Enlaces de publicación (posting):

http://www.edf.org/documents/3566_AbruptClimateChange.pdf

http://www.gbn.com/consulting/article_details.php?id=53

Ocean Circulation Shut Down by Melting Glaciers After Last Ice Age

NASA. Top Story

At the end of the last Ice Age 13 to 11.5 thousand years ago, the North Atlantic Deep Water circulation system that drives the Gulf Stream may have shut down because of melting glaciers that added freshwater into the North Atlantic Ocean over several hundred years, NASA and university researchers confirm. Since the Gulf Stream brings warm tropical waters north, Western Europe cooled.

The National Science Foundation (NSF) funded study also finds that if a shutdown persisted for a long enough time, the entire Northern Hemisphere would eventually cool.

The computer model simulations of ocean and atmosphere processes used in this study imply a similar phenomenon has the potential to occur in the future due to freshwater additions from increased rain and snow caused by global climate change.

"For the first time, it is shown that realistic additions of glacial meltwater into the North Atlantic would have shutdown North Atlantic Deep Water production over a period of a few hundred years if the initial ocean circulation was somewhat weaker than that of today," said David Rind, lead author of the study and a senior climate researcher at NASA's Goddard Institute for Space Studies in New York, NY. The study appears in the November 16 issue of Journal of Geophysical Research - Atmospheres.

When Rind and his colleagues entered realistic estimates of freshwater from melting glaciers into their model, they found the North Atlantic circulation stopped completely after some 300 years. When the model was adjusted to make the circulation weaker than it is today, cessation of the Gulf Stream took only 150-200 years, matching current estimates based on paleo-climate records .

Freshwater additions into the ocean through the St. Lawrence River have a profound effect on the ocean circulation.

"The more freshwater you add, and the longer you add it, the greater reduction in the North Atlantic circulation," Rind said. "According to our model, this is a linear response."

When the Gulf Stream moves warm surface water from the equator north through the Atlantic, the water cools, gets saltier due to evaporation and becomes very dense. By the time it approaches the coast of Newfoundland, or further northeast in the Norwegian Sea, it becomes dense enough to sink. This process is called overturning. The dense water then slowly travels through the deep water southward into the Southern Hemisphere, with the return flow to the north occurring at the surface.

But when freshwater gets mixed with the salty water in the North Atlantic, it makes the water less dense and slows the overturning process and the ocean circulation.

While the study finds that freshwater input could slow and stop overturning, this would not stop the Gulf Stream entirely. That's because the stream is partially pushed by winds. As a result, the model shows the reduced Gulf Stream would only transport about half as much heat northward, thereby cooling Western Europe. Were this to occur in a global warming scenario, it would act to partly counter the effects of projected greenhouse warming in parts of Western Europe.

Many scientists suspect more rainfall in parts of the Northern Hemisphere during this century as a result of greenhouse warming. That's because warmer temperatures increase the atmosphere's capacity to carry water. "The North Atlantic circulation may already be weakening due to freshwater rainfall additions associated with global warming," Rind said.

But the model shows a number of inconsistencies with previous studies on the last ice age. Those studies speculate that once freshwater stopped flowing, the ocean circulation would return within only a few decades, matching a rapid warming seen in the climate record. The model finds that deepwater circulation does not return for at least hundreds of years when the freshwater additions end. Also contrary to observations, the model showed cooling throughout the Northern Hemisphere; during the last ice age, the majority of the United States land mass did not appear to cool.

"It's hard to understand how parts of the Northern Hemisphere might have cooled to the magnitude suggested, but not North America," Rind said. "That seems to imply that either the paleo-records are being misinterpreted, or something else went on, something major that is not being accounted for. This isn't necessarily the end of the story."

UPDATES ON WARM SEAS AND ARCTIC ICE (The New York Times, 20.09.09)

http://dotearth.blogs.nytimes.com/2009/09/16/august-seas-warmest-in-120-years/

The National Climatic Data Center has released its review of worldwide sea surface temperatures for August and for the stretch from June through August and finds that both the month and the “summer” (as looked at from the Northern Hemisphere) were the warmest at least since 1880, when such records were first systematically compiled.

Sea ice in the Arctic appears to be starting the slow late-summer freeze after reaching its minimum extent several days ago, by a couple of estimates ( National Snow and Ice Data Center; International Arctic Research Center / Japan Aerospace Exploration Agency). Here’s the global sea ice trend, combining what’s going on up north and down south. This season’s Arctic ice retreat ranks well behind the extraordinary ice retreat of 2007 and also last year’s but remains below the average ice extent for the stretch since 1979, when satellites started monitoring Arctic conditions with some precision. Here’s a compilation of various groups’ experimental ice forecasts for this year and the results.

The National Oceanic and Atmospheric Administration summarized ocean temperature conditions for August in this description of the video above:

The world’s ocean surface temperature was the warmest for any August on record, and the warmest on record averaged for any June-August summer season, according to N.O.A.A.’s National Climatic Data Center in Asheville, N.C. Worldwide records began in 1880. Shown here is a visualization of the August global temperature anomalies — or in other words, how the average temperature in August differed from the average climate of 1961-1990. Notice that in some areas, such as the western United States, temperatures were much cooler than average. But overall, land and ocean temperatures were several degrees above normal.

Clearly the current El Niño warming in the tropical Pacific Ocean has contributed to the warm sea conditions. (UPDATE, 9/17: I’ve asked N.O.A.A. officials about their choice of temperature data sets, which has been criticized by some.) Variations in polar sea ice on short time scales, up or down, are essentially meaningless, my contacts studying the cryosphere always stress. Keep track of the long-term trends at the links above.

Q&A: Copenhagen climate change summit 2009

THE GUARDIAN
Environment ministers and officials are meeting in at a UN summit Copenhagen in December to thrash out global deal on climate change. What's on the agenda?

Abigail Edge and David Adam
guardian.co.uk, Friday 1 May 2009 15.47 BST
Article history

What is the Copenhagen climate change summit?
From 7 December environment ministers and officials will meet in Copenhagen for the United Nations climate conference to thrash out a successor to the Kyoto protocol. The conference, held at the modern Bella Center, will run for two weeks. The talks are the latest in an annual series of UN meetings that trace their origins to the 1992 Earth Summit in Rio, which aimed at coordinating international action against climate change.

What does COP15 stand for?
COP15 is the official name of the Copenhagen climate change summit — the 15th Conference of the Parties (COP) under the United Nations Framework Convention on Climate Change (UNFCCC). The COP is the highest body of the UNFCCC and consists of environment ministers who meet once a year to discuss developments in the convention.

Which countries are taking part in the climate change summit, and how many people will be there?
One hundred and ninety-two countries have signed the climate change convention. More than 15,000 officials, advisers, diplomats, campaigners and journalists are expected to attend COP15, joined by heads of state and government.

Who are the main players?
Developing countries, including China and India, believe it is the responsibility of wealthy industrialised nations such as the UK and US to set a clear example on cutting carbon emissions. Significantly, the US rejected the 1997 Kyoto protocol, with George Bush arguing that the 5% reductions required by Kyoto would "wreck [the American] economy" while making no demands on emerging economies. COP15's chances of success have been improved by President Barack Obama's stated intention to achieve an 80% reduction of greenhouse gas emissions by 2050.
In April, the secretary of state, Hillary Clinton, acknowledged the role the US had played in past climate emissions at a gathering of officials from the world's 17 largest economies. She said the US was "determined to make up for lost time both at home and abroad". "The US is no longer absent without leave," she said. However, Denmark's minister for climate and energy, Connie Hedegaard, has warned that American leadership on climate change will be undermined if the Obama administration does not pass laws swiftly to reduce carbon pollution.

What does the summit hope to achieve?
Officials will try to agree a new climate treaty as a successor to the Kyoto protocol, the first phase of which expires in 2012. According to Yvo de Boer, executive secretary of the UNFCCC, the four essentials needing an international agreement in Copenhagen are:

1 How much are industrialised countries willing to reduce their emissions of greenhouse gases?
2 How much are major developing countries such as China and India willing to do to limit the growth of their emissions?
3 How is the help needed by developing countries to engage in reducing their emissions and adapting to the impacts of climate change going to be financed?
4 How is that money going to be managed?

What are the sticking points?
The main issue is that of "burden-sharing". Climate scientists say that the world must stop the growth in greenhouse gas emissions and start making them fall from around 2015 to 2020. By 2050 they estimate the world must cut its emissions by 80% compared with 1990 levels to limit global warming to a 2C average rise.Money is also a major issue. The developing countries know they must hand over hundreds of billions of pounds to poorer nations, to help them adapt to the likely consequences. Earlier this year, Gordon Brown said this climate funding needed to reach $100bn a year by 2020. If the recent recession has made rich countries less willing to part with their cash, this could raise tensions in Copenhagen
But which countries must make the cuts and by how large should they be? For example, the rapidly growing Chinese economy has recently overtaken America as the world's largest emitter of carbon dioxide. Yet America has historically emitted far more emissions than China, and on a per capita basis Chinese emissions are around a quarter of those of the US.
The Chinese government argues that it has a moral right to develop and grow its economy — carbon emissions will inevitably grow with it. There is also the issue of industrialised nations effectively outsourcing carbon emissions to developing nations such as China. This is a consequence of huge quantities of carbon-intensive manufacturing taking place in China on behalf of buyers in the west. It wants consumer countries to take responsibility for the carbon emissions generated in the manufacture of goods, not the producer countries that export them.
Problems such as these have cast doubts on whether COP15 can succeed. There are also concerns about whether any action we take now to prevent climate change may be too little too late. A Guardian poll revealed almost nine out of 10 climate scientists do not believe political efforts to restrict global warming to an additional 2C — the level the EU defines as "dangerous" — will succeed.

CLIMATE CHANGE NOW- CAMBIO CLIMATICO AHORA

https://www.jpl.nasa.gov/news/news.php?feature=6584Páginas

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