Tag Archives: northern hemisphere

Infant Galaxy Offers Peek at Early Universe

EAST LANSING, Mich. — A Michigan State University astronomer is part of an international team of scientists that has discovered a galaxy so far, far away that its light was emitted not all that long after the Big Bang occurred.

The research of MSU’s physics and astronomy professor Megan Donahue and colleagues is detailed in the recent issue of the journal Nature. They found that this galaxy began emitting light “just” 490 million years after the Big Bang, when the universe was only 3.6 percent of its present age. (more…)

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Study Links Past Changes in Monsoon to Major Shifts in Indian Civilizations

A fundamental shift in the Indian monsoon has occurred over the last few millennia, from a steady humid monsoon that favored lush vegetation to extended periods of drought, reports a new study led by researchers at the Woods Hole Oceanographic Institution (WHOI). The study has implications for our understanding of the monsoon’s response to climate change.

The Indian peninsula sustains over a billion people, yet it lies at the same latitude as the Sahara Desert. Without a monsoon, most of India would be dry and uninhabitable. The ability to predict the timing and amount of the next year’s monsoon is vital, yet even our knowledge of the monsoon’s past variability remains incomplete. (more…)

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Nitrogen From Humans Pollutes Remote Lakes For More Than A Century

Nitrogen derived from human activities has polluted lakes throughout the Northern Hemisphere for more than a century and the fingerprint of these changes is evident even in remote lakes located thousands of miles from the nearest city, industrial area or farm.

The findings, published in the journal Science Dec. 16, are based on historical changes in the chemical composition of bottom deposits in 36 lakes using an approach similar to aquatic archeology. More than three quarters of the lakes, ranging from the U.S. Rocky Mountains to northern Europe, showed a distinctive signal of nitrogen released from human activities before the start of the 20th century, said Gordon Holtgrieve, a postdoctoral researcher at University of Washington School of Aquatic and Fishery Sciences and lead author of the report. The UW and a dozen other research institutions contributed to the research. (more…)

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NASA: Climate Change May Bring Big Ecosystem Changes

PASADENA, Calif. – By 2100, global climate change will modify plant communities covering almost half of Earth’s land surface and will drive the conversion of nearly 40 percent of land-based ecosystems from one major ecological community type – such as forest, grassland or tundra – toward another, according to a new NASA and university computer modeling study.

Researchers from NASA’s Jet Propulsion Laboratory and the California Institute of Technology in Pasadena, Calif., investigated how Earth’s plant life is likely to react over the next three centuries as Earth’s climate changes in response to rising levels of human-produced greenhouse gases. Study results are published in the journal Climatic Change. (more…)

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Cassini Captures Images and Sounds of Saturn Storm

PASADENA, Calif. — Scientists analyzing data from NASA’s Cassini spacecraft now have the first-ever, up-close details of a Saturn storm that is eight times the surface area of Earth.

On Dec. 5, 2010, Cassini first detected the storm that has been raging ever since. It appears approximately 35 degrees north latitude of Saturn. Pictures from Cassini’s imaging cameras show the storm wrapping around the entire planet covering approximately 2 billion square miles (4 billion square kilometers). (more…)

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Threading the Climate Needle: The Agulhas Current System

*Increased Agulhas “leakage” significant player in global climate variability*

The Agulhas Current which runs along the east coast of Africa may not be as well known as its counterpart in the Atlantic, the Gulf Stream. But now researchers are taking a closer look at this current and its “leakage” from the Indian Ocean into the Atlantic Ocean–and what that may mean for climate change.

In results of a study published in this week’s issue of the journal Nature, a team of scientists led by University of Miami Rosenstiel School of Marine & Atmospheric Science Oceanographer Lisa Beal, suggests that Agulhas leakage could be a significant player in global climate variability. (more…)

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Earth’s Lakes Warming Due to Climate Change

Lake Tahoe, seen here from Emerald Bay, was one of the primary validation sites for the global lake study. The lake, which straddles the borders of California and Nevada, is the largest alpine lake in North America. Image credit: NASA-JPL

WASHINGTON – In the first comprehensive global survey of temperature trends in major lakes, researchers have determined that Earth’s largest lakes have warmed during the past 25 years in response to climate change. 

Philipp Schneider and Simon Hook of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used satellite data to measure the surface temperatures of 167 large lakes worldwide. 

They reported an average warming rate of 0.45 degrees Celsius (0.81 degrees Fahrenheit) per decade, with some lakes warming as much as 1 degree Celsius (1.8 degrees Fahrenheit) per decade. The warming trend was global, and the greatest increases were in the mid- to high-latitudes of the Northern Hemisphere.  (more…)

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