TAU researcher develops surprising tool to measure our changing climate
The ionosphere, one of the regions of the upper atmosphere, plays an important role in global communications. Ionized by solar radiation, this electricity-rich region is used for the transmission of long wave communications, such as radio waves. Now Prof. Colin Price of Tel Aviv University‘s Department of Geophysical, Atmospheric and Planetary Sciences, working alongside PhD candidate Israel Silber, has discovered that the radio waves reflecting back to Earth from the ionosphere offer valuable news on climate change as well.
Their research shows that the strength of radio signals on the ground is a reliable indicator of temperature change above. Prof. Price and his team used simple radio antennae on the ground to measure radio waves broadcast by navigational transmitters around the globe, then compared information on the strength of these radio signals with data on temperature fluctuations in the upper atmosphere. They discovered that climate change in the upper atmosphere — caused by an abundance of greenhouse gases — may lead to a greater absorption of radio waves. Weaker signals could therefore be indicative of greater climate change.
Detailed in the Journal of Geophysical Research, this simple, cost-effective measurement can be a valuable contribution to the ongoing effort to track climate change, says Prof. Price, adding to measurements of ground and lower atmospheric temperatures to create a more holistic picture.
Global warming, upper atmospheric cooling
On the Earth’s surface and in the lower atmosphere, an increase of greenhouse gases has a warming effect, the gases acting as a “blanket” and keeping heat from escaping from the Earth into space. But these gases, including carbon dioxide, are increasing in the upper atmosphere as well, where they have a cooling effect.
When cooled, the ionosphere contracts and descends into the atmosphere to where air is denser — leading to a higher absorption of radio waves, Prof. Price explains. By examining satellite-gathered data on the temperature in the upper atmosphere and comparing results to measurements of radio wave amplitudes collected on the ground, the researchers were able to uncover a clear correlation, consistent over time. As the upper atmosphere gets colder, radio signals lose their strength.
While the sun is certainly the driving force behind changes in temperature in this region, it accounts for only 60 to 70 percent of temperature variations, says Prof. Price. The remaining variability could not be systematically measured until now. By adding measurements of radio waves taken on the ground to solar radiation estimates, researchers can now explain approximately 95 percent of temperature changes in the upper atmosphere.
The Latest on: Climate Change
- Dire warning: Climate Change Workshop discusses sea level rise on February 22, 2018 at 9:13 am
Scientists admit that their projections of sea level rise caused by global warming have been wrong. Unfortunately, those forecasts have consistently been too conservative in predicting the effects of manmade climate change, and real-world data keeps ... […]
- Climate scientists mull Category 6 storm classification, report says on February 22, 2018 at 8:31 am
"Scientifically, [six] would be a better description of the strength of 200 mph (320km/h) storms, and it would also better communicate the well-established finding now that climate change is making the strongest storms even stronger," he said. James Shaw ... […]
- The Public Pulse: Frank talk about climate change on February 22, 2018 at 6:32 am
I'd like to thank The World-Herald for letting Omahans know that we could hear a free lecture from the Vatican's own scientist, Dr. Veerabhadran Ramanathan, at Creighton. It's heartening to see in this time of great divisiveness that people of faith ... […]
- Bolivia's indigenous women cope with climate change on February 22, 2018 at 5:37 am
Bolivia is among the many countries around the world now dealing with the consequences of global warming, including extreme weather patterns. Especially vulnerable are the mostly indigenous farmer communities, which depend on regular seasonal patterns to ... […]
- Permafrost Experiments Mimic Alaska’s Climate-Changed Future on February 22, 2018 at 4:00 am
... Each Other A Crucial Climate Mystery Hides Just Beneath Your Feet Watch Shell's 1991 Video Warning of Catastrophic Climate Change Most dramatic of all is the speed-up in the carbon cycle that Schuur and his colleagues have observed. Plants in the ... […]
- One million trees have been pledged to ‘Trump Forest’ to offset US president’s climate change U-turn on February 22, 2018 at 1:58 am
One million trees have been pledged to a planting scheme designed to offset Donald Trump’s U-turn on climate change. Trump Forest was set up by environmentalists last year in a bid to counter the US president’s decision to withdraw from the Paris ... […]
- California cities and crazy climate change lawsuits - Do as I say, not as I do on February 21, 2018 at 9:56 pm
California cities are learning the meaning of hypocrisy. They have sued Exxon and other energy companies for concealing the costs of climate change from investors and customers. But now these same cities have confessed to the markets that they have no idea ... […]
- Generali to cut coal investments in new climate change strategy on February 21, 2018 at 4:42 pm
MILAN (Reuters) - Italian insurer Assicurazioni Generali has pledged to raise its investments in environmentally-friendly projects and divest from the coal industry as part of a new climate-change strategy. Europe's third biggest insurer said it would ... […]
- Defying Climate Change, Southeast US Is Getting Colder Instead Of Warmer Via Polar Vortex on February 21, 2018 at 4:33 pm
Counter to what most expected in a globally warming planet, the Southeast of the U.S. has been getting colder during winter and spring months instead of warmer. New research shines a light on the long noticed trend of cooling in the Southeast U.S. during ... […]
- U.S., Canadian provinces launch first cap-and-trade auction to battle climate change on February 21, 2018 at 2:59 pm
NEW YORK (Thomson Reuters Foundation) - The U.S. state of California and two Canadian provinces kicked off a cross-border auction of greenhouse gas emission credits on Wednesday, their first joint effort to buy and sell in the “cap and trade” market to ... […]
via Google News and Bing News