This extension of the COMET module “GOES-R: Benefits of Next Generation Environmental Monitoring” focuses on the Geostationary Lightning Mapper (GLM) instrument, the satellite's lightning mapper. The GLM will provide continuous lightning measurements over a large portion of the Western Hemisphere, mapping total lightning (intra-cloud and cloud–to–ground) flash rates and trends. GLM observations will improve local forecasts and warnings of severe weather and air quality, and provide new data for numerical weather prediction and studies of regional climate and climate change.

The first part of the lesson describes the need for real-time lightning information and introduces the capabilities of the GLM, which will fly on the next-generation GOES-R satellites.

The second section lets users explore the life cycle of a typical cloud-to-ground lightning flash, how it is observed by space and ground-based detection systems, and how lightning flashes translate into GLM observations.

The final section explores some of the many applications that will benefit from GLM observations including convection and severe weather nowcasting, warning of lightning ground strike hazards, aviation, atmospheric chemistry, quantitative precipitation estimation, tropical cyclones, fire ignitions, numerical weather prediction, and climate and global studies.