Groundwater measuring satellites launch into space

GRACE satellite system to boost groundwater


New technology could increase accuracy of hydrological groundwater models


New technology that the The Australian National University helped develop was hitched to a satellite and launched into space yesterday.

The GRACE satellite mission will keep track changes in water across the earth by monitoring sea levels, melting polar ice and groundwater. It’s the second iteration of the Gravity Recovery and Climate Experiment (GRACE) mission.

ANU scientists developed prototypes of the satellite’s laser system and the University’s Research School of Earth Sciences has  developed software to analyse data collected to estimate the melting of polar ice sheets, increases in ocean mass and hydrological changes across Australia and the world.

Professor Daniel Shaddock from ANU said the GRACE can “map” melting ice at the North and South pole - “but it can also tell us how the groundwater changes in the Murray Darling Basin from one month to the next,” Mr Shaddock said.

“The measurements that the satellite takes tells us how mass moves around the surface of the earth, and the only mass that moves around is water.”

Flying 200 kilometres apart, the twin satellites will measure tiny changes in the distance between the satellites.

“An increase in mass on Earth will make gravity stronger, which will cause one satellite to accelerate, which changes the distance between them,” Mr Shaddock said.

Dr Paul Tregoning, also from the Research School of Earth Sciences, said the sensory technology records the gravitational effect of water.

“The GRACE mission tells you change in mass between centre of earth and satellite and from that you can deduce how much is related to groundwater and how much is down to other elements,” Mr Tregoning said.

The GRACE mission measures the total water in a an area of 300 kilometres by 300km footprint.

“Over that region it delivers an accuracy of about 2cm of water height, which means we can use it to verify the accuracy of hydrological models,” Mr Tregoning said.

The next step for the team at ANU is to explore ways to use the data to improve the accuracy of groundwater models - which could feed into groundwater managers like the Murray Darling Basin Authority as well as assisting the Bureau of Meteorology.

Mr Shaddock said a previous study using data from the first GRACE mission revealed that a groundwater system in north west India had been reduced by “many gigatons” over five years.

“It was alarming, because the inputs of rain from the Himalayas were normal, and the runoff was normal as well.

“But irrigation use of groundwater had increased dramatically.”

The satellites were developed by American, German and Australian scientists, and Professor Shaddock led the Australian team that was funded by a $4.7 million Australian Space Research Grant.

The story Groundwater measuring satellites launch into space first appeared on Farm Online.


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