Mixing 5G and weather satellites could skew forecasts of next major storm

As the U.S. accelerates in deploying 5G and other new wireless technologies, there is increasingly cause for concern about the quality of future weather forecasts. Congress must act to protect the longstanding collection of weather satellite imagery to maintain storm monitoring in the 5G era.

Precise imaging of weather from space is the cornerstone of accurate weather forecasting that mitigates economic losses and proves advantageous for flight routing and tactical military operations. But there is a substantial risk that future weather satellite images could be contaminated with strong signals from new wireless networks. The result: less public awareness of harmful weather and other natural hazards.

The U.S. is an international leader in weather imaging from space, complementing similar European, Chinese and Japanese missions. In 2017, the U.S. launched the first of four satellites in the 20-year, $18.9-billion Joint Polar Satellite System (JPSS) mission. These satellites will collect much more data than the cloud imagery loop shown on the evening news. They will provide the weather equivalent of a medical CT scan of every brewing storm around the world, at least twice per day. This is possible because JPSS, like preceding satellites, observes natural Earth atmosphere, land and ocean signals.

But, earlier this year, the Federal Communications Commission (FCC) auctioned to telecommunications companies the rights to transmit some 5G signals near where JPSS is sensing the weather. The U.S. military, Commerce Department and National Aeronautics and Space Administration (NASA) protested.

While it might seem like science fiction, natural signals are particularly valuable because they are used to “see” through clouds, providing details about the weather near the surface that would not otherwise be available to detect the early signs of a brewing storm. A strong 5G network signal would leave the weaker natural signal indistinguishable to the satellite. Without clear imagery, meteorologists could be left in the dark, weather forecasts and warnings could suffer, and efforts to minimize casualties and damage from storms would be complicated. 

Satellites are responsible for over 99 percent of data that sophisticated global weather prediction computer models use. These computer models are based on scientific algorithms that help meteorologists forecast weather systems up to a week ahead. The impact of weather satellite data on model predictions has been clearly documented. This impact is particularly profound when dangerous weather is over the ocean, away from surface weather stations. The most notable example is the 2012 Superstorm Sandy forecast. 

The European Center for Medium-Range Weather Forecasts (ECMWF) examined the impact of excluding certain weather satellite data of and around Sandy. Without that data, there would have been “no useful guidance four to five days ahead” that Sandy would make landfall in New Jersey, as witnessed through its devastating consequences. Instead, it would have shown the hurricane headed across the Atlantic in the direction of Europe.

The good news is that Americans can have both 5G and accurate storm warnings if there are practical limits on where 5G transmitters are placed and the strength of their signals. And there is tremendous motivation to pursue 5G within these parameters. If internet access is ubiquitous, so is commerce, and economies can grow.

But the last two years have underscored the burden of natural disasters on the $20-trillion American economy: the combined cost of such U.S. disasters in 2017 and 2018 exceeded $400 billion in total. Reliable weather predictions for dangerous storms decrease unnecessary evacuations, saving some coastal residents from unforeseen expenses. It costs a minimum of around $1 million to evacuate a mile of U.S. coastline. Evacuation costs for heavily populated coastal communities and intense storms can reach up to $50 million per mile.

The economic and human cost of less warning lead-time ahead of major storms is too high to not protect weather satellites. To assure the continuation of reliable severe weather alerts and maintain the value of U.S. and similar international satellites for that purpose, Congress must explicitly protect weather imaging from harmful interference in the 5G era and request further studies of the impact of missing satellite data on global and local weather forecasts. Until that time, the deployment of new 5G networks must be constrained in power and extent.

Jordan Gerth, Ph.D., is an associate researcher at the Cooperative Institute for Meteorological Satellite Studies on the University of Wisconsin-Madison campus. His is also the chairman of the American Meteorological Society Committee on Radio Frequency Allocations. Follow him on Twitter @jjgerth.