Los astrobiólogos de los Estados Unidos y Alemania, registraron el nivel más alto conocido de la radiación UV solar que llega a la superficie terrestre. Esto fue hace unos 10 años. El 29 de diciembre de 2003, el índice de radiación Ultra Violeta (IUV) alcanzó su punto máximo, alcanzando un abrasador 43.3 sobre las montañas de los Andes en Bolivia. Para poner esto en contexto, un bañista en los Estados Unidos espera una IUV de 8 o 9 en un día de verano. Incluso con esos números, no se puede escapar el día sin las quemaduras solares. No obstante, le ha tomado a los científicos 10 años para detallar un informe de estos datos, teniendo en cuenta las variables y anomalías monitoreadas desde una red internacional de dosímetros (o Eldonets por sus siglas en inglés) que miden la radiación UV en todo el mundo. Este sistema se compone de más de 100 estaciones en los 5 continentes para dar cuenta de la variación atmosférica sobre cada estación.
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You have probably heard that melting permafrost is a big contributor to increasing the levels of greenhouse gases in our atmosphere, and that melting permafrost may even cause an unstoppable acceleration of global warming. New research, however, supported by the National Science Foundation (NSF), counters this widely-held scientific view that thawing permafrost uniformly accelerates atmospheric warming, indicating instead that certain arctic lakes store more greenhouse gases than they emit into the atmosphere. The study, published this week in the journal Nature, focuses on thermokarst lakes, which occur as permafrost thaws and creates surface depressions that fill with melted fresh water, converting what was previously frozen land into lakes.
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The mystery behind the movements of flocking starlings could be explained by the areas of light and dark created as they fly, new research suggests. The research, conducted by the University of Warwick and published in the journal PNAS, found that flocking starlings aim to maintain an optimum density at which they can gather data on their surroundings. This occurs when they can see light through the flock at many angles, a state known as marginal opacity. The subsequent pattern of light and dark, formed as the birds attempt to achieve the necessary density, is what provides vital information to individual birds within the flock.
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In a significant victory for Prime Minister Tony Abbott, the Australian Senate has voted to repeal the country's two-year-old carbon tax. Abbott made dismantling the tax one of the cornerstones of his campaign last September even as Australia remains one of the highest carbon emitters per capita in the industrialized world.
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Residents of California have been noting something disconcerting when they hit the grocery store this year: it's a terrible year for stone fruit. Despite the fact that it's the height of summer, peaches, nectarines, apricots, plums, cherries and their ilk are much more expensive than unusual, and of much poorer quality, too. What's going on? The answer lies in the state's extreme drought, which wreaked havoc on numerous crops this year, including stone fruit. The state's agriculture may be undergoing some major shifts in the coming years thanks to climate change and natural shifts in rainfall levels, and it's not the only region looking at a drier future.
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Un estudio que involucró a abejas con etiquetas de radiofrecuencia diminutas encontró que la exposición a largo plazo a un pesticida de neonicotinoides obstaculiza la capacidad de las abejas para buscar alimentarse de polen. La investigación realizada por Nigel Raine, profesor de la Universidad de Guelph, y Richard Gill, del Imperial College de Londres, muestra cómo la exposición a pesticidas a largo plazo afecta el comportamiento individual de las abejas en el día a día, incluyendo la recolección de polen y flores que las abejas obreras escogen para visitar.
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