Satellite tracking of water vapor, critical for accurate forecasts, may be foiled by cellphone tower transmissions
Federal agencies are competing with one another over radio waves used to help predict changes in the climate as the sky is increasingly cluttered with noise from billions of smartphones.
On one side are NOAA and NASA. They have developed space satellites that passively capture and decode the faint energy signals given off by changes in water vapor, temperatures, rain and wind that determine future weather patterns.
They are supported by weather and earth scientists who say the signals are threatened by 5G, the emerging “fifth generation” of wireless communication devices that could create enough electronic noise on radio spectrums to reduce forecasting skills and distort computer models needed to predict the progress of climate change.
On the other side are wireless communication companies, smartphone manufacturers and the Federal Communications Commission (FCC), which regulates the use of the radio frequency spectrum. The FCC has begun a series of moves to allow companies to “share” spectrums used by federal science-related agencies to accommodate the rapid growth of 5G.
The FCC has been supporting 5G since 2016 when its former chairman, Tom Wheeler, initiated a policy he called “Spectrum Frontiers” to push the growth of 5G. “In a 5G world, the internet of everything will be fully realized,” he asserted. “Everything that can be connected will be connected.”
Creating more room for billions of smartphones and other 5G devices is “damn important,” he told reporters, “because it means U.S. companies will be first out of the gate.“
In 2019, the House Committee on Science, Space and Technology raised questions about two studies prepared by NOAA and NASA that predicted the FCC’s rush to auction off space within radio frequencies would disrupt weather data needed for forecasts. Ajit Pai, the chairman of the FCC at the time, responded that there was no evidence of potential interference and proceeded with an auction.
Committee leaders called for an examination by the Government Accountability Office (GAO). The report, released last month, said demand for spectrum space is “growing exponentially,” with the potential for between 25 billion to 50 billion devices competing for space by 2025.
It said the arguments among U.S. agencies concerning weather and climate forecasting problems were “highly contentious.” The FCC sought support from the Trump White House, according to the GAO, and despite the lack of consensus, the weaker rules of the FCC’s Spectrum Frontiers program became the U.S. position.
It was then adopted by the International Telecommunication Union (ITU), based in Geneva, Switzerland. It writes the global rules.
The GAO reported that officials in NOAA and NASA are worried that the push for the less stringent rules on the expanded sharing of weather-related spectrums will continue at the next meeting of the ITU, which is set for 2023.
“These data are absolutely critical,” explained William Mahoney III, associate director of the National Center for Atmospheric Research and one of the leaders of the science-related agencies involved in the dispute.
In an interview, he explained the biggest issue involves a spectrum called 24 gigahertz, which weather satellites use to monitor natural microwave signals produced by water vapor at various levels in the atmosphere. The device they use is a microwave radiometer.
“It is one of those things that are a gift of nature,” Mahoney said, because the signals from the varying presence of water vapor allows satellites to explore the weather forming in different layers of the atmosphere. “A third of the current forecasting skill comes from this data,” he added, noting that the data captured by orbiting satellites can “make the difference between a blue sky day and a tornado day.”
But the signals made by water vapor and other natural weather signatures become fainter in a cacophonous surge of phone signals. “If you have a large network of cellphone towers transmitting many orders of magnitude more power near the ground, some of that reflects upward and parts of the atmosphere will become very noisy,” Mahoney said.
The stakes of losing data are high.
“This is not an issue of academics or researchers losing access to a data set, this is about not having the necessary information to protect life and property,” Mahoney told members of the House Science Committee.
Accurate weather data, he added, is necessary for agriculture, aviation, water management, monitoring wildfires and managing energy production, as well as for U.S. defense agencies.
A second spectrum at 16 megahertz connects satellites with signals from a variety of automated gauges used by the U.S. to measure water levels in streams and rivers and wind speeds. The satellites collect the signals and send the resulting data to the National Weather Service and private weather reporting companies that are also concerned about rising “noise levels,” Mahoney explained in the interview.
Steven Root, president of the American Weather and Climate Industry Association, wrote to the committee that the interference caused by sharing the band “will significantly threaten the distribution of crucial weather information by AWCIA members like AccuWeather, UNISYS Weather and WeatherBank, Inc., that the nation relies on to respond immediately with the highest quality information to dangerous weather like tornadoes, hurricanes and wildfires.”
Another expert witness told the House panel that the most “insidious” impact of rising noise levels on a weather spectrum would emerge if they caused errors or gaps in the weather data that is undetected. The erroneous data might be included in computer models that scientists use for, among other things, predicting future climate behavior.
There is new technology to detect “contaminated” data, explained David Lubar, a project leader on spectrum issues at the Aerospace Corp., a nonprofit agency established by Congress to provide technical advice on space programs.
Lubar said agencies working on the technology lack the funding to develop and deploy it on new satellites. “I am heartened that this hearing is being held to examine these issues,” he told the panel.
Just where the FCC will go next with its Frontier Spectrum policy on 5G is unclear. According to the House Science Committee, it has already taken in almost $2 billion from 29 winning bidders for space on the 24 gigahertz band.
An FCC spokesman said the agency “is now laser focused on forging strong relationships with its federal partners and revitalizing the interagency coordination process so that it once again is able to produce results for American consumers and the economy.”
Better coordination between these agencies ultimately means more spectrum and more innovation to help restore American wireless leadership, he said. “We look forward to working with other federal agencies to review the GAO recommendations.”
In a Congress that is deeply divided on many issues, the House Science Committee appears to have a bipartisan consensus that more work remains to be done among federal agencies before international regulations on radio spectrums are made.
“The [GAO] report makes it clear that the existing process is flawed and highlights a number of instances in which coordination fell apart. We can’t afford to have this happen again.” said Rep. Frank Lucas of Oklahoma, the panel’s top Republican.
Rep. Eddie Bernice Johnson (D-Texas), the chairwoman of the Science Committee, said in a statement to E&E News that “improvements to the interagency process for spectrum auctions remain necessary.”
She said the “FCC must—at a minimum—apply globally-set standards to protect both domestic science and our diplomatic standing,” adding that her panel will work to “ensure that we use scientific evidence to protect critical services for our nation.”