30 years of slowing Pacific circulation may have changed climate
A recent slowing in the circulation of Pacific Ocean waters could have raised Pacific sea surface temperatures. It may even mean that less carbon has reached the atmosphere from the ocean surface over the past two decades.
Across the Pacific, water circulates in two giant loops in the Northern and Southern Hemispheres. It flows from the subtropics to the tropics about at a depth of 100-400 metres, rises to the
Climate prediction just got trickier, according to two new studies appearing in the current issue of the journal Science. Analysis of more than two decades of satellite data shows that more sunlight entered the tropics and more heat escaped to space in the 1990s than a decade earlier. Moreover, current climate models fail to account for the new findings, suggesting that they may contain more uncertainty than previously thought.
For the earth’s climate to remain unchanged, the planet’s ener
Researchers from the University of Amsterdam have demonstrated that the climate in South Mexico changed following the collapse of the Maya empire. From preserved pollen grains the paleoecologists could deduce that the climate quickly became dryer.
The climate becoming dryer, explains the decrease in the population following the collapse of the Maya empire. The climate researchers have therefore helped to solve an archaeological mystery.
With the help of pollen grains, the paleoeco
Ireland’s huge hexagonal columns are a natural consequence of lava cooling.
The Giant’s Causeway is not the work of men or monsters, but a natural consequence of how lava cools and solidifies, new computer simulations suggest.
The causeway is a field of roughly hexagonal basalt columns up to 40 feet high on the shores of County Antrim in Northern Ireland. It arose when a flow of volcanic rock split into hexagonal columns to relieve stress, according to Eduardo Jagla
The delicate balance of life and death in Africa is nowhere more evident than on the banks of the continent`s mighty rivers. Rural communities depend on the rich silt brought down by rivers for farming but they are also at risk of devastating floods, as are urban dwellers in informal settlements that are often built on floodplains.
Dr Sue Marriott, reader in earth sciences at UWE`s Faculty of the Built Environment, is setting off this month to help with training environmental managers in fl
Results from a 20-year study reveal dramatic ecological changes to lakes in Antarctica caused by a 1°C temperature increase. The findings, reported this week in SCIENCE, are yet more evidence of extreme changes in the Antarctic Peninsula region. This area has experienced some of the most rapid warming of anywhere on Earth in the past 50 years (2.5°C). The study lakes, on Signy Island, lie some 700 km north-east of the Antarctic Peninsula.
Scientists from the Cambridge-based British Antarctic Surv
Scientists received several day’s warning of abnormal seismic activity.
Two seismological stations on Mount Nyiragongo in eastern Congo gave several days’ advance warning of the volcano’s possible eruption, scientists working in the area say.
But the lack of a functioning government in the war-torn region may have prevented the evacuation of the nearby city of Goma, where 45 were confirmed dead and an existing humanitarian crisis was worsened by the eruption.
One of the really big challenges in anthropology is to date accurately the arrival of humans in the different continents. New results, to be published in a forthcoming issue of the Journal of Quaternary Science, show that humans arrived in Australia a lot earlier than was previously thought.
It is generally argued that humans evolved in Africa and then spread out over the other continents progressively through time, arriving in the most distant, such as Australasia, relatively recently. The
One of the more controversial environmental issues, which emerged in the final years of the Soviet era, was the plan to dam and reverse the flow of north-flowing rivers in order to irrigate the dry southern steppes. This scheme was roundly criticised by scientists and environmentalists at the time because of fears for the impact on the Arctic Ocean and global climate. It now appears that nature performed this experiment some 90,000 years ago.
This months issue of the Journal of Quaternary
Argon traces keep tabs on climate change.
A new method for detecting tiny quantities of a rare form of the element argon may help oceanographers to trace the vast undersea currents that regulate our planet’s climate.
The technique can pick out one atom of the rare isotope argon-39 (39Ar) amid 10 million billion other atoms. That’s equivalent to detecting less than a litre of water in America’s 300-mile Lake Michigan.
Philippe Collon, a nuclear physicist at the Lamon
Natural randomness punctuated past ice ages with warm spells.
Natural randomness in the world’s climate system may have caused the frequent, fast and fleeting returns to warm conditions during past ice ages, say two German scientists 1 .
Andrey Ganopolski and Stefan Rahmstorf at the Potsdam Institute for Climate Impact Research think that the flickering character of ice-age climate is a signature of stochastic resonance. This is the counter-intuitive phenome
In the first weeks of the New Year a team of European scientists drilled successfully through 2002 metres of ice at Dome Concordia, high on East Antarctica`s plateau – one of the most hostile places on the planet. A specially created laboratory on the ice enabled scientists to analyse, for the first time, past climate shifts within hours of each 3 m length of core being drilled – rather than waiting months or years for detailed study back in European labs. The team, working on a seven-year Antarctic
While the rest of world has warmed, Antarctica has grown chillier, scientists say. According to a new study, air temperature on the southernmost continent fell by 0.7 degree Celsius per decade between 1986 and 2000 – a cooling trend that has come with ecological consequences.
The findings may come as a surprise to climate researchers. Conventional wisdom holds that the polar regions should be the first to show the effects of global warming. And previous work has indeed detected increased t
Not only geologists are interested in giant canyons of Kursk Magnetic Anomaly, but also soil scientists. There is very convenient place to watch old soils, which earlier were on the surface. As the canyons grew wider, details of ancient landscapes and their changes appear. While studying one of those canyons, Svetlana Sycheva from the Institute of Geography Russian Academy of Sciences has found that earlier there was a system of large ravines, now buried under a thick layer of sediments.
It
The 2001 calendar year was slightly warmer than “average,” according to global climate data gathered by instruments aboard NOAA satellites.
The composite global temperature for 2001 was 0.06 degrees C (about 0.11 degrees Fahrenheit) warmer than the 20-year (1979-to-1998) average, said Dr. John Christy, a professor of atmospheric science and director of the Earth System Science Center at The University of Alabama in Huntsville (UAH).
Compared to other years, 2001 was the ninth warmes
A spectacular phenomenon
This theme issue of Philosophical Transactions A (a Royal Society journal) deals with the phenomenon of ball lightning, a rarely seen and slow-moving luminous phenomenon usually associated with thunderstorms. A collection of previously unpublished sightings is presented, including close-up encounters describing the detailed internal structure of the balls. Many of these observations are from scientifically or technically trained people, probably doubling the n
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