Mostrando entradas con la etiqueta The North Atlantic. Mostrar todas las entradas
Mostrando entradas con la etiqueta The North Atlantic. Mostrar todas las entradas

domingo, 8 de noviembre de 2015

NASA : NASA to Fly, Sail North to Study Plankton-Climate Change Connection .- NASA volará, Vela del Norte para estudiar la conexión del cambio climático y el Plancton........

Hola amigos: A VUELO DE UN QUINDE EL BLOG., NASA comienza un estudio de cinco años este mes del ciclo anual del fitoplancton y el impacto que las pequeñas partículas en el aire emitidas por el océano tienen sobre el Atlántico Norte sensibles al clima.
The agency's North Atlantic Aerosols and Marine Ecosystems Study (NAAMES);  recogerá datos durante las campañas de medición de los buques y aeronaves y combinar esos datos con lecturas de satélites y sensores océano continuas. La primera de las cuatro misiones de investigación de temporada comienza 06 de noviembre y continúa hasta principios de diciembre.
More information....

NASA’s C-130H Hercules airborne laboratory begins research flights over the North Atlantic Nov. 12 from St. John’s, Newfoundland
NASA’s C-130H Hercules airborne laboratory begins research flights over the North Atlantic Nov. 12 from St. John’s, Newfoundland, Canada, the agency's North Atlantic Aerosols and Marine Ecosystems Study (NAAMES).
Credits: NASA
Woods Hole Oceanographic Institution's research vessel Atlantis
The research vessel Atlantis, operated by the Woods Hole Oceanographic Institution, will provide detailed ship-based measurements of plankton in the North Atlantic as part of the North Atlantic Aerosols and Marine Ecosystems Study (NAAMES).
Credits: Woods Hole Oceanographic Institution
 
NASA begins a five-year study this month of the annual cycle of phytoplankton and the impact that small airborne particles emitted from the ocean have on the climate-sensitive North Atlantic.

The North Atlantic Aerosols and Marine Ecosystems Study (NAAMES) will collect data during ship and aircraft measurement campaigns and combine that data with continuous satellite and ocean sensor readings. The first of four seasonal research missions begins Nov. 6 and continues through early December.

NASA’s C-130H Hercules airborne laboratory will begin research flights Nov. 12 from St. John’s International Airport in St. John’s, Newfoundland. The flights will be coordinated with the research vessel (R/V) Atlantis, operated by the Woods Hole Oceanographic Institution in Woods Hole, Massachusetts. Atlantis will provide detailed ship-based measurements of plankton in the North Atlantic.

“We will be studying an ocean region that every year exhibits one of the largest natural phytoplankton blooms on Earth,” said Mike Behrenfeld, NAAMES principal investigator from Oregon State University in Corvallis. “These plankton are also known to release organic compounds into the atmosphere that can be measured as far away as Ireland. That makes the North Atlantic an ideal place to study how plankton blooms are recreated each year by ecological and physical processes, and how ocean biology is involved in the sea-air exchange of organic aerosols and trace gases that may influence clouds and climate.”

The C-130H will fly eastward to rendezvous with and overfly the global-class, floating laboratory-ship Atlantis during its approximately 26-day research cruise. By combining ship, airborne, computer modeling, sustained satellite and autonomous sensor data, scientists hope to improve their predictions of ecosystem and aerosol changes in a warming ocean.

Plankton ecosystems in the ocean are strongly interconnected with climate and life on Earth. Plankton production, responding to a warming climate, results in environmental impacts such as changes in fisheries production, uptake of atmospheric carbon dioxide, and ocean emissions of climate-regulating aerosols. The ability to predict the consequences of a warming ocean depends on resolving conflicting theories about what controls plankton ecosystems and their aerosol emissions.

NASA’s Langley Research Center in Hampton, Virginia, has science and project management responsibilities for NAAMES and science instruments onboard the C-130H. The agency’s Goddard Space Flight Center in Greenbelt, Maryland, leads project data management. The NAAMES ship and airborne science-instrument teams involve more than 20 different research facilities and academic institutions. NASA’s Wallops Flight Facility Aircraft Office in Virginia operates the C-130H research aircraft to support airborne scientific research activities.

The NASA C-130H and the R/V Atlantis supporting the NAAMES mission will be available to the media at two different events this month. On Wednesday, Nov. 4 from 10 to 11:30 a.m. EST, media can tour the Atlantis at Woods Hole, located at 86 Water St. The C-130H will be available on Tuesday, Nov. 10 from 10 to 11:30 a.m. Newfoundland Time Zone, in Hangar #4 of St. John’s International Airport, located at RCAF Road in St. John’s.

NAAMES is part of NASA’s second series of Earth Venture suborbital investigations that provide an innovative approach to regularly address Earth science research that accommodates evolving scientific priorities. Earth Venture investigations are part of NASA's Earth System Science Pathfinder Program, managed at Langley for NASA’s Science Mission Directorate in Washington.

NASA researchers collect and study data from space, air, land and sea to tackle challenges facing the world today, including improved environmental prediction and natural hazard and climate change preparedness. NASA develops new ways to observe and study Earth's interconnected natural systems with long-term data records. The agency freely shares this unique knowledge and works with institutions around the world to gain new insights into how our planet is changing.

For more information about NAAMES, go to:

http://naames.larc.nasa.gov

For more information about NASA’s Earth science activities, visit:

http://www.nasa.gov/earth

- end -
Steve Cole
Headquarters, Washington
202-358-0918
stephen.e.cole@nasa.gov

Chris Rink
Langley Research Center, Hampton, Va.
757-864-6786
chris.rink@nasa.gov
Last Updated: Nov. 4, 2015
Editor: Karen Northon
Tags:  Climate,
NASA
Guillermo Gonzalo Sánchez Achutegui
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sábado, 28 de junio de 2014

The National Science Foundation: Ancient ocean currents may have changed pace and intensity of ice ages

Slowing of currents may have flipped switch

earth seen from outer space showing the North Atlantic currents
About 950,000 years ago, North Atlantic currents, Northern Hemisphere ice sheets underwent changes.
Credit and Larger Version
June 26, 2014
Climate scientists have long tried to explain why ice-age cycles became longer and more intense some 900,000 years ago, switching from 41,000-year cycles to 100,000-year cycles.
In a paper published this week in the journal Science, researchers report that the deep ocean currents that move heat around the globe stalled or may have stopped at that time, possibly due to expanding ice cover in the Northern Hemisphere.
"The research is a breakthrough in understanding a major change in the rhythm of Earth's climate, and shows that the ocean played a central role," says Candace Major, program director in the National Science Foundation (NSF)'s Division of Ocean Sciences, which funded the research.
The slowing currents increased carbon dioxide (CO2) storage in the oceans, leaving less CO2 in the atmosphere. That kept temperatures cold and kicked the climate system into a new phase of colder, but less frequent, ice ages, the scientists believe.
"The oceans started storing more carbon dioxide for a longer period of time," says Leopoldo Pena, the paper's lead author and a paleoceanographer at Columbia University's Lamont-Doherty Earth Observatory (LDEO). "Our evidence shows that the oceans played a major role in slowing the pace of the ice ages and making them more severe."
The researchers reconstructed the past strength of Earth's system of ocean currents by sampling deep-sea sediments off the coast of South Africa, where powerful currents originating in the North Atlantic Ocean pass on their way to Antarctica.
How vigorously those currents moved can be inferred by how much North Atlantic water made it that far, as measured by isotope ratios of the element neodymium bearing the signature of North Atlantic seawater.
Like tape recorders, the shells of ancient plankton incorporate these seawater signals through time, allowing scientists to approximate when currents grew stronger and when weaker.
Over the last 1.2 million years, the conveyor-like currents strengthened during warm periods and lessened during ice ages, as previously thought.
But at about 950,000 years ago, ocean circulation slowed significantly and stayed weak for 100,000 years.
During that period the planet skipped an interglacial--the warm interval between ice ages. When the system recovered, it entered a new phase of longer, 100,000-year ice age cycles.
After this turning point, deep ocean currents remained weak during ice ages, and ice ages themselves became colder.
"Our discovery of such a major breakdown in the ocean circulation system was a big surprise," said paper co-author Steven Goldstein, a geochemist at LDEO. "It allowed the ice sheets to grow when they should have melted, triggering the first 100,000-year cycle."
Ice ages come and go at predictable intervals based on the changing amount of sunlight that falls on the planet, due to variations in Earth's orbit around the sun.
Orbital changes alone, however, are not enough to explain the sudden switch to longer ice age intervals.
According to one earlier hypothesis for the transition, advancing glaciers in North America stripped away soils in Canada, causing thicker, longer-lasting ice to build up on the remaining bedrock.
Building on that idea, the researchers believe that the advancing ice might have triggered the slowdown in deep ocean currents, leading the oceans to vent less carbon dioxide, which suppressed the interglacial that should have followed.
"The ice sheets must have reached a critical state that switched the ocean circulation system into a weaker mode," said Goldstein.
Neodymium, a key component of cellphones, headphones, computers and wind turbines, also offers a good way of measuring the vigor of ancient ocean currents.
Goldstein and colleagues had used neodymium ratios in deep-sea sediment samples to show that ocean circulation slowed during past ice ages.
They used the same method to show that changes in climate preceded changes in ocean circulation.
A trace element in Earth's crust, neodymium washes into the oceans through erosion from the continents, where natural radioactive decay leaves a signature unique to the land mass from which it originated.
When Goldstein and Lamont colleague Sidney Hemming pioneered this method in the late 1990s, they rarely worried about surrounding neodymium contaminating their samples.
The rise of consumer electronics has changed that.
"I used to say you could do sample processing for neodymium analysis in a parking lot," said Goldstein. "Not anymore."
-NSF-
Media Contacts Cheryl Dybas, NSF, (703) 292-7734,
cdybas@nsf.gov
Kim Martineau, LDEO, (845) 365-8708,
Related WebsitesNSF Grant: Late Quaternary Variability of the Agulhas Thermohaline Valve from Nd Isotopes in Planktonic Foraminifera:
The National Science Foundation (NSF) is an independent federal agency that supports fundamental research and education across all fields of science and engineering. In fiscal year (FY) 2014, its budget is $7.2 billion. NSF funds reach all 50 states through grants to nearly 2,000 colleges, universities and other institutions. Each year, NSF receives about 50,000 competitive requests for funding, and makes about 11,500 new funding awards. NSF also awards about $593 million in professional and service contracts yearly.
Useful NSF Web Sites:
NSF Home Page: http://www.nsf.gov
NSF News: http://www.nsf.gov/news/
For the News Media: http://www.nsf.gov/news/newsroom.jsp
Science and Engineering Statistics: http://www.nsf.gov/statistics/
Awards Searches: http://www.nsf.gov/awardsearch/
 
map of the world showing the route of the great ocean conveyor currents
Ocean currents slowed 950,000 years ago, triggering colder but less frequent ice ages.
Credit and Larger Version
Scientist Leo Pena analyzes fossil plankton shells on a computer to reconstruct ocean circulation.
Scientists (pictured: Leo Pena) analyzed fossil plankton shells to reconstruct ocean circulation.
Credit and Larger Version
isolated neodymium isotopes from fossils
In an Ultra Clean Lab, neodymium isotopes in fossils were isolated and measured.
Credit and Larger Version
The scientific drillship JOIDES Resolution at sea
The scientific drillship JOIDES Resolution was used as a platform to collect deep-ocean sediment.
Credit and Larger Version
Science cover
The researchers' findings are described in the June 27 issue of Science.
Credit and Larger Versión
The National Science Foundation (NSF)
Guillermo Gonzalo Sánchez Achutegui

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