Weather satellites use certain radio frequency bands in the electromagnetic spectrum to monitor water vapor in the atmosphere, but bands near these frequencies may also be used by 5G networks. The roll-out of 5G mobile networks could have a big impact on weather forecasters’ ability to predict major weather events. Concerns are drawn particularly in regards to 26 GHz band (between 24.25 GHz to 27.5 GHz) which is being sold internationally as part of the 5G spectrum. The closeness of a natural frequency to that of the 5G network could spell massive difficulties for Earth-orbiting satellites. For example, satellites like the European MetOp probes monitor energy radiating off the Earth with the goal of assessing humidity in the atmosphere. Using the 23.8-gigahertz frequency, where water vapor in the atmosphere gives off a feeble signal, these probes give researchers 24/7 access to data in addition to the possibility to look through clouds.
Ofcom in the UK is considering to auction this band in the future and the auction will see the communications regulator offer a private company the chance to buy the exclusive right to communicate using these frequencies on the electromagnetic spectrum. However, the potential 5G band is very close to the 23.8 GHz frequency which is emitted by water vapor. Meteorological satellites use such high frequency radio signals to track weather patterns – and the 5G signal could potentially interfere with this data collection.
There are multiple ideas on how to control 5G from influencing weather satellites. The World Meteorological Organization (WMO) is recommending -55 decibel watts. In measuring controlled interference, the lower a number, the stricter are the controls. The U.S. is proposing a weaker number, -20 decibel watts. There have not been any formal studies looking at how precisely this interference could interfere with 23.8 GHz weather satellites. “But the more we lose, the greater the impact will be,” says Jordan Gerth, a meteorologist at the University of Wisconsin–Madison.