GPS global thermometer to monitor climate change

February 17th, 2008 - 3:23 pm ICT by admin  

London , Feb 17 (ANI): The Global Positioning System can not only detect your cars geographical location on the globe, but could also be used as a global thermometer to monitor climate change.

The idea is based on a comparatively new technique for taking atmospheric measurements called GPS radio occultation.

In this technique, signals from GPS satellites are received by making use of a satellite in low-Earth orbit (LEO).

Signals, while passing through the atmosphere, are slightly refracted, and the angle of refraction depends on temperature and the amount of water vapour in the atmosphere.

Many research satellites have instruments that measure GPS signals in this way, including the German CHAMP mission, and the joint US/Taiwan COSMIC mission. These measurements are used to help in determining the amount of water in the atmosphere, as well as temperature and density, which are useful in weather forecasting.

However, two researchers at the Met Office Hadley Centre in Exeter and the European Centre for Medium-Range Weather Forecasts in Reading , both in the UK , have indicated that climate change can be confirmed by directly using the measurements of refraction.

Mark Ringer and Sean Healy have described the technique in which they have used computer models to calculate the expected change in the refraction of the GPS signals as global warming continues.

Even though, the measurements will be affected by natural atmospheric variations, the researchers have forecasted that, within 10 years, a strong signal of man-made climate change should be detectable.

It was indicated by their model that radio waves passing through the stratosphere will be bent through an angle 4 percent greater than today.

“I think it’s pretty significant. Here’s another way you can use this data in a way that will, in theory, point out a change in climate, New Scientist magazine quoted Robert Kursinski, an atmospheric scientist at the University of Arizona , as saying.

The findings appear in a paper to be published in Geophysical Research Letters. (ANI)

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