Tag Archives: son nghiem

NASA: Warm Rivers Play Role in Arctic Sea Ice Melt

The heat from warm river waters draining into the Arctic Ocean is contributing to the melting of Arctic sea ice each summer, a new NASA study finds.

A research team led by Son Nghiem of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., used satellite data to measure the surface temperature of the waters discharging from a Canadian river into the icy Beaufort Sea during the summer of 2012. They observed a sudden influx of warm river waters into the sea that rapidly warmed the surface layers of the ocean, enhancing the melting of sea ice. A paper describing the study is now published online in the journal Geophysical Research Letters. (more…)

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NASA Helps Melt Secrets of Great Lakes Ice

Two scientists from NASA and NOAA have developed a new space-based technique for monitoring the ice cover of the Great Lakes that is so accurate it can identify a narrow channel of open water cut through the ice by an icebreaker — even at night.

“In the dark, it’s difficult to read a map that’s right in front of you,” said Son Nghiem of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., one of the developers of the new technique. “Yet we now have a way to use satellite radars almost 500 miles [800 kilometers] out in space to see through clouds and darkness and map ice across the Great Lakes.” (more…)

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Satellites See Double Jeopardy for SoCal Fire Season

PASADENA, Calif. – New insights into two factors that are creating a potentially volatile Southern California wildfire season come from an ongoing project using NASA and Indian satellite data by scientists at NASA’s Jet Propulsion Laboratory, Pasadena, Calif.; and Chapman University, Orange, Calif.

The scientists tracked the relationship between rainfall and the growth and drying-out of vegetation in recent months, during an abnormally dry year. They found the timing of rains triggered regional vegetation growth in January and early February, which then dried out faster than normal during a period of low rainfall, strong winds and high temperatures in March and April. The combination likely elevates wildfire risks by increasing available fuel. (more…)

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NASA Finds Sea Ice Driving Arctic Air Pollutants

PASADENA, Calif. – Drastic reductions in Arctic sea ice in the last decade may be intensifying the chemical release of bromine into the atmosphere, resulting in ground-level ozone depletion and the deposit of toxic mercury in the Arctic, according to a new NASA-led study.

The connection between changes in the Arctic Ocean’s ice cover and bromine chemical processes is determined by the interaction between the salt in sea ice, frigid temperatures and sunlight. When these mix, the salty ice releases bromine into the air and starts a cascade of chemical reactions called a “bromine explosion.” These reactions rapidly create more molecules of bromine monoxide in the atmosphere. Bromine then reacts with a gaseous form of mercury, turning it into a pollutant that falls to Earth’s surface. (more…)

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