Satellites Reveal ‘Hot Lightning’ Strikes Are Most Likely To Start Wildfires

Scientists are using new satellite sensor data, combined with info from the terrestrial U.S. National Lightning Detection Network, to help identify the most dangerous lightning strikes. They found that “hot lightning” is the most dangerous as it can ignite wildfires, damage electrical equipment, and even kill people. Slashdot reader Wave723 shares a report from IEEE Spectrum: With new tools, researchers can now distinguish the most damaging lightning strikes from the many millions of others that occur every year. Already, the U.S. National Lightning Detection Network keeps a record of virtually all lightning that strikes the ground anywhere in the United States. That network is maintained by Helsinki-based Vaisala, which built it 30 years ago and sells the data to the National Weather Service and to utilities, airports, seaports, mines, and sporting arenas. Vaisala operates a global lightning detection network, as well. But the company hasn’t been able to make one specific measurement that could provide clues as to how dangerous a given strike is likely to be — until now. Before the end of this year, Vaisala will debut a beta product that will make this valuable measurement available to clients for the first time. The product (which is now running but is not yet commercially available) combines data from its terrestrial U.S. and global lightning detection networks with new information from a pair of optical sensors, known as Geostationary Lightning Mappers (GLMs). The sensors are currently orbiting Earth aboard two weather satellites that belong to the U.S. National Oceanic and Atmospheric Administration (NOAA). The company’s goal is to use all of this data to detect the presence of a single phenomenon: something called a continuing current, which is thought to occur in about 11 percent of lightning strikes. Lightning that harbors a continuing current is more likely to start fires and damage homes or equipment. Such “hot lightning,” as it’s called, can be spotted by the Geostationary Lightning Mappers, which detect rapid changes in brightness in the 777.4-nanometer (near infrared) band associated with lightning.