July 31, 2013
New Tool Uses Radio Waves To Predict Climate Change
Lee Rannals for redOrbit.com - Your Universe Online
Tel Aviv University (TAU) scientists developed a new tool to measure climate change by using radio waves.
The team wrote in the Journal of Geophysical Research about a cost-effective measurements that can be a valuable contribution to the ongoing effort to track climate change. The researchers show the strength of radio signals on the ground is a good indicator of temperature change above.
Prof. Colin Price of TAU's Department of Geophysical, Atmospheric and Planetary Sciences, and colleagues used radio antennae on the ground to measure radio waves broadcast by navigational transmitters around the globe and compared information on the strength of these signals with temperature fluctuations in the ionosphere. They found climate change could lead to greater absorption of radio waves, which means weaker signals could indicate climate change.
When the ionosphere cools, it contracts and descends into the atmosphere to where air is denser. By examining satellite-gathered data on the temperature of this region, they were able to uncover a clear correlation between radio waves and temperature.
The sun accounts for 60 to 70 percent of the temperature variations in the ionosphere, but the remaining variability had not been systematically measured until now. Researchers are now able to explain about 95 percent of temperature changes in the upper atmosphere.
Price said this new technique could be a valuable tool in monitoring climate change, such as the measurement of ground temperatures. The new method will allow scientists to monitor the upper atmosphere without the need of expensive equipment like satellites. For every one degree of warming in the lower atmosphere, there is a corresponding ten-degree cooling in the upper atmosphere. This system could reveal more about the ionosphere than ever before.
According to the researchers, this method could make it possible to study long and short term changes in the upper atmosphere, such as the impact of solar storms or thunderstorms.
NASA is planning a mission called Dynamo to help study the currents that pass through the ionosphere. This mission will launch two sounding rockets, 15 seconds apart, that will collect information about the ionosphere's neutral and charged particles. The second rocket is a Terrier-Improved Orion that will be studying the upper atmosphere's winds believed to drive dynamo currents.