New Satellite to Predict Future Climate Change
A torpedo-shaped satellite - known as the gravity field and steady-state ocean circulation explorer, will help predict how the world is going to change." Scientists are preparing to launch a new satellite to make more precise measurements of the Earth's gravitational field and so help improve predictions about global warming with a more precise picture of the ocean currents.
By comparing the surface shape of the oceans with the undulations in the gravitational field, scientists can arrive at a more accurate picture of the oceans' currents - the flows that transport vast amounts of heat around the planet and so have a profound impact on the global climate.
The satellite will complete a map of the gravitational field once every 70 days and stay in operation for about 18 months.
GOCE is equipped with a triple-accelerometer gradiometer, accurate to within one part in one hundred trillion of standard Earth gravity. Don't pretend you understand that - a one hundred trillionth is beyond the human minds ability to usefully picture. For reference, it's the size of a virus compared to a sixteen wheeler truck.
The GOCE is the first in a series of Earth Exploring satellites - it's companions will be CRYOSAT, SMOS, AEOLUS and the excellently-named SWARM. Five satellites in orbit with names like that - the ESA have not confirmed that the quintuplet will merge to form a giant alien-battling robot in times of distress, but only because it's so obvious it doesn't need to be said.
The image above provides a global model of the Earth's gravity field and of the geoid. The geoid (the surface of equal gravitational potential of a hypothetical ocean at rest) serves as the classical reference for all topographical features -important for studies of Earth interior processes, ocean circulation, ice motion and sea-level change.
The satellite was due to launch this week from the Plesetsk cosmodrome,
about 500 miles north of Moscow. But engineers delayed takeoff for two
weeks after problems with the guidance and navigation system. When
launched, it will orbit from pole to pole at an altitude of about 160
miles. This is very low for satellites, but it needs to be close to the
Earth to be able to measure minute fluctuations in gravity - about 10
million-millionths of the gravity we feel on Earth. To measure these
the engineers developed sophisticated control mechanisms that dampen
other forces acting on the spacecraft, including buffeting by cosmic
rays.
Posted by Casey Kazan with Luke McKinney.
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