Two researchers from The University of Alabama in Huntsville (UAH) Earth System Science Center were recently awarded US$402,000 to discover what aspects of lightning flashes are captured by NASA’s lightning imaging sensor on the International Space Station and how these characteristics can provide information about how thunderstorms strengthen in intensity.
The funding came from the NASA 2022 Research Opportunities in Space and Earth Science and was awarded to Dr Sarah Stough, a research associate at UAH and principal investigator on the project, along with co-investigators Dr Daniel Walker, a research scientist at UAH, and Dr Mason Quick, an atmospheric physicist at NASA’s Marshall Space Flight Center. Over the three-year award period, the team will analyze the frequency and type of lightning emissions NASA’s space-based optical lightning sensors can detect.
By understanding atmospheric conditions that influence the initiation of a lightning flash from a storm cloud and determining the characteristics of lightning that are seen from space, Stough and Walker hope that this research will influence how the next generation of NASA’s space-based lightning detection instrumentation is developed.
Walker said, “Lightning emits radiation across the electromagnetic spectrum and can vary between storm classifications. Most of the time, we’re only seeing a small portion of the lightning spectrum from any one instrument.”
The team will review lightning data from seven flights previously conducted during a collaborative field campaign in 2017. Instruments used to detect lightning flashes during this field campaign included NASA’s spaceborne optical lightning imaging sensor on the International Space Station, NASA’s Fly’s Eye Geostationary Lightning Mapper Simulator aboard the NASA ER-2 aircraft and the NASA ground-based lightning mapping array network.
Collecting lightning data from space down to the ground enables the team to generate a profile of lightning from cloud to ground produced by the observed thunderstorms. Stough noted, “Having a complete picture of all the lightning emitted by the thunderstorms observed will allow our team to improve the diagnostic and predictive capabilities of space-based optical lightning detection by getting a better idea of how these instruments ‘see’ a lightning flash.”
Lightning is also tied to the updraft of a thunderstorm. As an updraft moves liquid water content into the colder regions of the cloud, it creates ice particles and helps to give ice in the storm cloud an electrical charge. Eventually, layers of negative and positive charges will develop within the cloud where a flash will initiate.
“Our project will also use radar data to help us measure the updraft and detect the ice content in the cloud associated with lightning flashes,” Stough stated. “Once the flash initiates, we examine the characteristics of the storm that made it. Little flashes occur near more turbulent updrafts, while bigger flashes typically occur in calmer stratiform regions of a thunderstorm where a charge has been able to build for a longer time.”
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