Tag Archives: ocean surface

Mercury levels in Pacific fish likely to rise in coming decades

ANN ARBOR — University of Michigan researchers and their University of Hawaii colleagues say they’ve solved the longstanding mystery of how mercury gets into open-ocean fish, and their findings suggest that levels of the toxin in Pacific Ocean fish will likely rise in coming decades.

Using isotopic measurement techniques developed at U-M, the researchers determined that up to 80 percent of the toxic form of mercury, called methylmercury, found in the tissues of deep-feeding North Pacific Ocean fish is produced deep in the ocean, most likely by bacteria clinging to sinking bits of organic matter. (more…)

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Century-Old Science Helps Confirm Global Warming

A new NASA and university analysis of ocean data collected more than 135 years ago by the crew of the HMS Challenger oceanographic expedition provides further confirmation that human activities have warmed our planet over the past century.

Researchers from the University of Tasmania, Sandy Bay, Australia; and NASA’s Jet Propulsion Laboratory, Pasadena, Calif., combined the ship’s measurements of ocean temperatures with modern observations from the international Argo array of ocean profiling floats. They used both as inputs to state-of-the-art climate models, to get a picture of how the world’s oceans have changed since the Challenger’s voyage. (more…)

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European Satellite Confirms UW Numbers: Arctic Ocean is on Thin Ice

The September 2012 record low in Arctic sea-ice extent was big news, but a missing piece of the puzzle was lurking below the ocean’s surface. What volume of ice floats on Arctic waters? And how does that compare to previous summers? These are difficult but important questions, because how much ice actually remains suggests how vulnerable the ice pack will be to more warming.

New satellite observations confirm a University of Washington analysis that for the past three years has produced widely quoted estimates of Arctic sea-ice volume. Findings based on observations from a European Space Agency satellite, published online in Geophysical Research Letters, show that the Arctic has lost more than a third of summer sea-ice volume since a decade ago, when a U.S. satellite collected similar data. (more…)

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NASA to Launch Ocean Wind Monitor to Space Station

PASADENA, Calif. – In a clever reuse of hardware originally built to test parts of NASA’s QuikScat satellite, the agency will launch the ISS-RapidScat instrument to the International Space Station in 2014 to measure ocean surface wind speed and direction.

The ISS-RapidScat instrument will help improve weather forecasts, including hurricane monitoring, and understanding of how ocean-atmosphere interactions influence Earth’s climate. (more…)

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Scientists Define New Limits of Microbial Life in Undersea Volcanoes

A third of Earth’s organisms live in rocks and sediments, but their lives have been a mystery

By some estimates, a third of Earth’s organisms live in our planet’s rocks and sediments, yet their lives are almost a complete mystery.

This week, the work of microbiologist James Holden of the University of Massachusetts-Amherst and colleagues shines a light into this dark world.

In the journal Proceedings of the National Academy of Sciences (PNAS), they report the first detailed data on methane-exhaling microbes that live deep in the cracks of hot undersea volcanoes. (more…)

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Aquarius Yields NASA’s First Global Map of Ocean Salinity

PASADENA, Calif. – NASA’s new Aquarius instrument has produced its first global map of the salinity of the ocean surface, providing an early glimpse of the mission’s anticipated discoveries.

Aquarius, which is aboard the Aquarius/SAC-D (Satélite de Aplicaciones Científicas) observatory, is making NASA’s first space observations of ocean surface salinity variations — a key component of Earth’s climate. Salinity changes are linked to the cycling of freshwater around the planet and influence ocean circulation. (more…)

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Aquarius Makes First Ocean Salt Measurements

PASADENA, Calif. – NASA’s Aquarius instrument has successfully completed its commissioning phase and is now “tasting” the saltiness of Earth’s ocean surface, making measurements from its perch in near-polar orbit.

“This marks the end of the long odyssey to design, build and launch this mission, and the start of a new journey of scientific exploration,” said Aquarius Principal Investigator Gary Lagerloef of Earth & Space Research, Seattle. “Scientists from around the world are ready and waiting to study this important new satellite measurement for ocean and climate research.” (more…)

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