On June 10, 2011, NASA launched into space Aquarius, a scientific instrument used to measure the salt content of the world's oceans, information that could help confirm scientists' suspicions that climate change is accelerating the world's water cycle. Aquarius is part of a joint mission between NASA and Argentina's space agency.
On September 22, 2011, NASA reported that Aquarius had 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.
Aquarius Principal Investigator Gary Lagerloef of Earth & Space Research in Seattle said.
"Aquarius' salinity data are showing much higher quality than we expected to see this early in the mission. Aquarius soon will allow scientists to explore the connections between global rainfall, ocean currents and climate variations."
The new map, which shows a tapestry of salinity patterns, demonstrates Aquarius' ability to detect large-scale salinity distribution features clearly and with sharp contrast. The map is a composite of the data since Aquarius became operational on Aug. 25. The mission was launched June 10 from Vandenberg Air Force Base in California. Aquarius/SAC-D is a collaboration between NASA and Argentina's space agency, Comisión Nacional de Actividades Espaciales (CONAE).
Michael Freilich, director of NASA's Earth Science Division at agency headquarters in Washington said.
"Aquarius/SAC-D already is advancing our understanding of ocean surface salinity and Earth's water cycle. Aquarius is making continuous, consistent, global measurements of ocean salinity, including measurements from places we have never sampled before."
To produce the map, Aquarius scientists compared the early data with ocean surface salinity reference data. Although the early data contain some uncertainties, and months of additional calibration and validation work remain, scientists are impressed by the data's quality.
Aquarius science team member Arnold Gordon, professor of oceanography at Columbia University in Palisades, N.Y., and at the university's Lamont-Doherty Earth Observatory said.
"Aquarius has exposed a pattern of ocean surface salinity that is rich in variability across a wide range of scales. This is a great moment in the history of oceanography. The first image raises many questions that oceanographers will be challenged to explain."
Click Image To Enlarge
The map shows several well-known ocean salinity features such as higher salinity in the subtropics; higher average salinity in the Atlantic Ocean compared to the Pacific and Indian oceans; and lower salinity in rainy belts near the equator, in the northernmost Pacific Ocean and elsewhere. These features are related to large-scale patterns of rainfall and evaporation over the ocean, river outflow and ocean circulation. Aquarius will monitor how these features change and study their link to climate and weather variations.
Other important regional features are evident, including a sharp contrast between the arid, high-salinity Arabian Sea west of the Indian subcontinent, and the low-salinity Bay of Bengal to the east, which is dominated by the Ganges River and south Asia monsoon rains. The data also show important smaller details, such as a larger-than-expected extent of low-salinity water associated with outflow from the Amazon River.
Aquarius was built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., and the Goddard Space Flight Center in Greenbelt, Md., for NASA's Earth Systems Science Pathfinder Program. JPL is managing Aquarius through its commissioning phase and will archive mission data. Goddard will manage Aquarius mission operations and process science data. CONAE provided the SAC-D spacecraft and the mission operations center.
Eric Lindstrom, Aquarium program scientist at NASA said.
"A sort of grand problem in Earth science is to understand the water cycle -- evaporation from the ocean, clouds, rain, the formation of ice, the runoff from the land back into the sea. Ocean salinity turns out to be a pretty useful diagnostic of the big picture."
Aquarius will be able to measure changes in salinity caused by evaporation, rain and snow, and melting sea ice. Its measurements of ocean saltiness will also help scientists understand how changes in salinity affect the deep currents that drive ocean circulation.
A way to measure extremes
Recent studies have suggested that relatively salty portions of the oceans are getting saltier, and areas where water is relatively fresh are getting fresher. Lindstrom said,
"If we can confirm water cycle acceleration, what this means to us in a practical way is that there are more extremes. There's more water circulating through the atmosphere, more flooding, more drought. I am just really excited about the idea that we can get this data all over the planet and be able to diagnose what's going on with the water cycle."
Gary Lagerloef, a principal investigator on the Aquarius mission, said the instrument can measure minute changes in the ocean's salt content.
Said Lagerloef, president of Earth and Space Research, a Seattle -based research institute,
"If you take a dash of salt, an eighth of a teaspoon, and you put that in a gallon of water, that's the amount of salinity change Aquarius will be able to observe from month to month over any part of the ocean."
Aquarius is also notable for another reason. It's the first climate satellite NASA has launched since a faulty rocket sent the space agency's Glory probe crashing into the ocean in February. A similar problem doomed the launch of another climate satellite, the Orbiting Carbon Observatory, in 2009.
Two veteran travelers
But there is an important difference between Aquarius and the previous failed launches: It launached into space on a Delta II rocket, not the Taurus XL rockets that carried Glory and OCO.
NASA built the instrument in the United States but later sent it to Bariloche, Argentina, where crews from Argentina's space agency placed it on the SAC-D satellite framework, which carry seven other scientific instruments.
Officials then shipped the completed SAC-D, with Aquarius aboard, to Sâo José dos Campos, Brazil, for environmental testing at a Brazilian Space Agency facility.
COMMENTARY: Aquarius will continue to map the concentration of dissolved salt at the ocean's surface, information that scientists will use to study the ocean's role in the global water cycle and how this is linked to ocean currents and climate. Sea surface temperature has been monitored by satellites for decades, but it is both temperature and salinity that determine the density of the surface waters of the ocean. Aquarius will provide fundamentally new ocean surface salinity data to give scientists a better understanding of the density-driven circulation; how it is tied to changes in rainfall and evaporation, or the melting and freezing of ice; and its effect on climate variability.
Salinity is defined as the number of grams of salt dissolved in 1000 grams of ocean water.
The salinity of average seawater is 35‰ [this symbol is read as permil – out of 1000 rather than 100 as you would have in percent (%) – your book gives some weird symbol for permil that looks like the congruent symbol (≈) I have never seen used for permil before. In this class we will use ‰].
On average, there are 35 grams of salt in every 1000 grams of sea water (35 parts per thousand or 35‰). NOTE: Because all salinities are assumed to reported as permil, they often leave off the ‰ symbol (reported as simply 35 assuming that you know its unit is ‰).
The map of the ocean's salinity is shown below:
NASA's Jet Propulsion Lab and the California Institute of Technology produced this really cool video titled "Eyes On The Earth 3D". Check it out.
For a long time meteorologists have suspected that ocean currents and the temperature and salinity of our oceans have a direct affect on our weather. Just a small increase in the temperature and salinity of our oceans can have devastating affects on surface temperatures. As ocean temperatures rise or decrease, the this creates a sort of sauna effect or cooling effect, increasing surface temperatures or lowering them in others parts of the globe. This is why we are experiencing the frequency and intensity of tornados, rain storms, hurricanes, very cold winters and drought in different parts of the world.
Aquarius will confirm how the temperature and salinity of the world's oceans change over time. I hope Aquarius makes it into earth orbit and does it job. We really need to understand our oceans processes and how they affect things on the surface of Earth. just hope that we are not too late for the sake of mankind and avoid this:
Courtesy of an article dated May 18, 2011 appearing in Scientific American
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