Aquarius (observation satellite)
Aquarius, the new NASA instrument produced its first global map of the salinity of the ocean surface of the Earth.
This first image of the global ocean salinity, demonstrates the ability of Aquarius to clearly identify a large scale, the characteristics of distribution of salinity. This card has pleasantly surprised the scientists of the mission. The colors of the map represent the salt concentration in grams of salt per kilogram of sea water colors yellow and red represent areas of higher salinity, while blue and purple indicate areas of lower salinity .
Some areas have been cleared (black areas) because the digital data collected are not consistent.
The average salinity on the map is about 35 grams of salt per kilogram of sea water However, this new map does not reveal any major news, but confirms mostly well-known characteristics of ocean salinity.
It confirms, for example, the salinity is higher in the subtropics, the average salinity is higher in the Atlantic Ocean from the Pacific and Indian oceans, the salinity is lower, near the equator and northern Pacific Ocean.
A large scale, these features are related to rainfall, evaporation from oceans, river flows and ocean circulation. Aquarius mission to monitor how these characteristics will change over time and determine their relationship to changes in climate and weather.
Other important regional characteristics, are highlighted on this map, as the high contrast of both sides of drylands. For example in western Indian sub-continent, salinity is high, and east of the Bay of Bengal, the salinity is low because the area is influenced by the Ganges and the monsoon rains in the southern Asia. The data also show small important details, such as low salinity associated with the output in the ocean, the Amazon River. To produce the map, mission scientists have Aquarius calibrate the preliminary data.
These initial data contain some uncertainties, which in the months ahead will demand more work for validation. For example, measurements of ocean areas in the south are still not reliable because they were disrupted by high winds and low surface temperatures.
On this model, scratches visible north-south, are artifacts of small residual calibration errors are not real.
In addition, the low salinity, close to the ice-covered land, and proximity to the coast ice, require further analysis. Aquarius is a satellite observation first specialized in spatial variations in surface salinity of the oceans, but also a key component for the analysis of the climate of the Earth, the cycle of fresh water around of our planet and the influence of ocean circulation.
The Aquarius satellite was launched June 10, 2011, the California based Vandenberg Air Force.
Aquarius was built by NASA's Jet Propulsion Laboratory in Pasadena, Calif., and Goddard Space Flight Center in Greenbelt, Md. NASA. JPL manages the mission phase of Aquarius in its commissioning and data archiving. Goddard manages the Aquarius mission operations and science. CONAE provides the spacecraft SAC-D, an optical camera, a thermal camera with Canada, a microwave radiometer, other sensors and the mission center operations.
France and Italy also help in the construction of instruments.
"The data show a salinity of Aquarius much better than we expected to see so early in the mission," said Gary Lagerloef (Earth & Space Research in Seattle).
"Aquarius will soon allow scientists to explore the links between global precipitation, ocean currents and climate variations. "
"Aquarius has already advanced our understanding of ocean surface salinity and the water cycle on Earth," said Michael Freilich, director of NASA's Earth Science Division at the headquarters of the agency in Washington.
"Aquarius collects continuous measurements of global ocean salinity, including measures to places we have never sampled before. "
"Aquarius presents a model, the salinity of ocean surface on a large scale, which is rich in variations," said Gordon Arnold, a professor of oceanography at Columbia University in New York and the Lamont-Doherty Earth Observatory of Columbia University in Palisades, New York.
"It's a great moment in the history of oceanography. The first picture raises many questions and challenges put to oceanographers who will respond. "
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Image:First composite image of ocean salinity provided by the Aquarius satellite, its first 2 weeks of observation (from August 25 to September 11, 2011).
The average salinity on the map is about 35 grams of salt per kilogram of sea water.
Observatory Aquarius / SAC-D (Satélite of Aplicaciones Científicas) is a collaboration between NASA and the space agency of Argentina, Comisión Nacional de Actividades Espaciales (CONAE). Instrument Aquarius / SAC-D Observatory, produced by: GSFC / JPL