Tag Archives: tropical pacific ocean

Ancient shellfish remains rewrite 10,000-year history of El Niño cycles

The planet’s largest and most powerful driver of climate changes from one year to the next, the El Niño Southern Oscillation in the tropical Pacific Ocean, was widely thought to have been weaker in ancient times because of a different configuration of the Earth’s orbit. But scientists analyzing 25-foot piles of ancient shells have found that the El Niños 10,000 years ago were as strong and frequent as the ones we experience today. (more…)

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Greenland melting due equally to global warming, natural variations

The rapid melting of Greenland glaciers is captured in the documentary “Chasing Ice.” The retreat of the ice edge from one year to the next sends more water into the sea.

Now University of Washington atmospheric scientists have estimated that up to half of the recent warming in Greenland and surrounding areas may be due to climate variations that originate in the tropical Pacific and are not connected with the overall warming of the planet. Still, at least half the warming remains attributable to global warming caused by rising carbon dioxide emissions. The paper is published May 8 in Nature. (more…)

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UCLA study yields more accurate data on thousands of years of climate change

Research also helps unravel the mystery of retreating glaciers in the Pacific Ocean’s western tropics

Using a cutting-edge research technique, UCLA researchers have reconstructed the temperature history of a region that plays a major role in determining climate around the world.

The findings, published online Feb. 27 in the journal Nature Geoscience, will help inform scientists about the processes influencing global warming in the western tropical Pacific Ocean. (more…)

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El Niño tied to melting of Antarctica’s Pine Island Glacier

Pine Island Glacier is one of the biggest routes for ice to flow from Antarctica into the sea. The floating ice shelf at the glacier’s tip has been melting and thinning for the past four decades, causing the glacier to speed up and discharge more ice.

Understanding this ice shelf is a key for predicting sea-level rise in a warming world. A paper published Jan. 2 in the advance online version of the journal Science shows that the ice shelf melting depends on the local wind direction, which is tied to tropical changes associated with El Niño. (more…)

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Recent Antarctic climate, glacier changes at the ‘upper bound’ of normal

In the last few decades, glaciers at the edge of the icy continent of Antarctica have been thinning, and research has shown the rate of thinning has accelerated and contributed significantly to sea level rise.

New ice core research suggests that, while the changes are dramatic, they cannot be attributed with confidence to human-caused global warming, said Eric Steig, a University of Washington professor of Earth and space sciences. (more…)

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UA Scientists Find Evidence of Roman Period Megadrought

*A new study at the UA’s Laboratory of Tree-Ring Research has revealed a previously unknown multi-decade drought period in the second century A.D. The findings give evidence that extended periods of aridity have occurred at intervals throughout our past.*

Almost nine hundred years ago, in the mid-12th century, the southwestern U.S. was in the middle of a multi-decade megadrought. It was the most recent extended period of severe drought known for this region. But it was not the first.

The second century A.D. saw an extended dry period of more than 100 years characterized by a multi-decade drought lasting nearly 50 years, says a new study from scientists at the University of Arizona. (more…)

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