It is in the hope of tackling this vexing problem that scientists from the European Space Agency (ESA) are preparing to launch the Gravity field and steady-state Ocean Circulation Explorer (GOCE), which will help improve measurements of the Earth's gravitational field and, in turn, improve predictions about climate change. The satellite will help climate scientists arrive at a more accurate picture of the ocean currents, The Guardian's James Randerson reports, by comparing their surface shape with the fluctuations in the planet's gravitational field.
Image from the ESA
GOCE, which will remain in orbit for around 20 months, will complete a map of the Earth's gravitational field once every 70 days; it will orbit from pole to pole at an altitude of 160 miles -- low by most satellites' standards, but necessary for it to precisely record the minute changes in gravity that regularly occur.
To measure these tiny variations, GOCE is equipped with 3 pairs of ultra-sensitive accelerometers arranged in 3-D. Their particular arrangement allows them to respond to the planet's gravitational acceleration differently and, in so doing, simultaneously measure 6 unique, but complementary, components of its gravity field.
The "Formula 1" of spacecrafts (that's what the ESA is calling it), GOCE will become the most advanced gravity space mission to data when it launches next month. Here's a brief snippet explaining how GOCE works from the ESA's latest press release:
Over its lifetime of about 20 months, GOCE will map these global variations in the gravity field with extreme detail and accuracy. This will result in a unique model of the geoid, which is the surface of equal gravitational potential defined by the gravity field – crucial for deriving accurate measurements of ocean circulation and sea-level change, both of which are affected by climate change. GOCE-derived data is also much needed to understand more about processes occurring inside the Earth and for use in practical applications such as surveying and levelling.
Since the gravitational signal is stronger closer to Earth, the 'arrow-like', five-metre long GOCE satellite has been designed to cut through of what remains of the Earth's atmosphere at just 250 km above the surface of the planet. This low-orbiting spacecraft is the first mission to employ the concept of gradiometry - the measurement of acceleration differences over short distances between an ensemble of proof masses inside the satellite.
More about satellites
::Satellite Images Reveal Two of Greenland's Biggest Glaciers Are Losing More Ice
::Brazil to Develop Satellite to Monitor Deforestation, Urban Expansion
::NASA Satellite Could Make Floating Ocean Wind Farms Possible