Close to midnight on January 3, 2017, Samantha Edgington and a team of scientists gathered to remotely open the door of an instrument on the GOES-16 weather satellite they had spent a decade creating. The tool, a geostationary lightning mapper (GLM) meant to track lightning on Earth from space, was 35,000 kilometers in the sky above Earth onboard a newly-launched satellite.
“To be honest, I didn’t think we were going to see anything very much when we first opened the door,” said Edgington, a system architect at Lockheed Martin, “No one could sit still as we waited for the data to show us how the instrument was working.”
Once the door opened, Edgington’s expectations were wildly exceeded and the team erupted in cheer.
“We open the door, we get not only [lightning], but we also get background images every two-and-a-half minutes,” Edgington said, “The first that came in, it was the sunrise over the Atlantic in Brazil, and it was just the most beautiful thing I’d ever seen.”
“We had all invested years of our careers into this moment,” Edgington said, “And it was surprisingly emotional to see the results and share the moment with colleagues we had worked with—for ten years in my case.”
The results Edgington mentioned will be used to help forecasters broadcast earlier warnings about severe weather.
GOES-16, part of a series of GOES weather satellites, was jointly developed by the National Aeronautics and Space Administration and the National Oceanic and Atmospheric Administration (NOAA). Lockheed Martin was contracted to design and build the most recent satellite series, including both GOES-16 and the GLM.
Earle Williams, principal research engineer at MIT, explained what the GOES-16 GLM adds to meteorologists’ toolkits.
While previous satellites could only detect lightning from low Earth orbit for only short bursts of time, he said, GOES-16’s GLM can “map lightning over the entire Western Hemisphere.”
So far, the GLM onboard GOES-16 has sent back to Earth an unprecedented amount of lightning data that will help meteorologists and forecasters gain a better understanding of severe weather phenomena.
“GLM has collected more data on lightning from space so far than all the rest of the lightning mapping missions combined in just the time it’s been in orbit,” Edgington said.
The satellite and its instrument are currently in a test orbit, where scientists have been working to improve the GLM and the data it can provide.
Scott Rudlosky, a physical scientist at NOAA who works on GOES-16 GLM, has been closely monitoring the instrument. He said its performance will continue to improve as scientists optimize the its algorithms. The biggest changes, he said, were incorporated in October and November of 2017, though already, GLM collected valuable data during the recent hurricane season.
“Having the GOES-16 active during the 2017 hurricane season likely doubled the amount of information that we have to help link total lightning activity to hurricane intensity changes,” Rudlosky said.
The instrument tracked increased lightning in the eyewalls of Irma and Maria, and lots of lightning in the outer bands of Harvey, Edgington said.
Lightning sustains an electrical balance between the sky and Earth, and during storms, the frequency of lightning correlates with how quickly a storm intensifies. “[Meteorologists] use lightning data to get a sense of a storm’s intensity, for determining where a forest fire might have been initiated, etc.” said Scott Steiger, an associate professor of meteorology at Oswego State University of New York.
In the planning and creation of the GLM, Edgington said, “the main push was more accurate tornado predictions, but we think it’s going to be able to help with other things as well, like flash flooding or hail.”
Rudlosky hopes the data from the GLM will be available soon once the instrument is in its final position: “With any luck, these data should be available to all [National Weather Service] forecasters by the end of January 2018.”