The Geostationary Lightning Mapper is a single-channel, near-infrared optical transient detector that can detect the momentary changes in an optical scene, indicating the presence of lightning. GLM will measure total lightning activity continuously over the Americas and adjacent ocean regions with near uniform spatial resolution of approximately 10 km. GLM will provide early predictions of intensifying storms and severe weather events. It will also provide data for long-term climate studies. The instrument will aid forecasting of weather events that could affect aviation safety and efficiency. GLM is unique both in how it operates and in the information it collects. While ground-based sensors only provide cloud-to-ground lightning coverage, GLM provides total lightning activity detection with both cloud-to-ground and cloud-to-cloud coverage. Also, ground-based systems can only provide coverage over land. GLM will identify growing, active and potentially destructive thunderstorms in areas over both land and oceans.
The instrument will collect information such as the frequency and location of lightning events to detect the intensification of thunderstorms and tropical cyclones, which are often accompanied by increased lightning activity. Research and testing has demonstrated GLM’s potential for improvement in tornado warning lead time and reduction of false alarm rates. It is anticipated that GLM data will have immediate applications to aviation weather services, climatological studies, and severe thunderstorm forecasts and warnings. Data from the instrument will also be used to produce a long term database to track decadal changes in lightning activity. This is important due to lightning’s role in maintaining the Earth-atmosphere electrical balance.
GLM measurements can provide vital information to help the operational weather, aviation, disaster preparedness, and fire communities in a number of areas:
Improvement in tornado and severe thunderstorm lead times and false alarm reduction
Early warning of lightning ground strike hazards
Advancements in the initialization of numerical weather prediction models through better identification of deep convection
Improved routing of commercial, military, and private aircraft over oceanic regions where observations of thunderstorm intensity are scarce
Improved ability to monitor intensification or decay of storms during radar outages, or where radar coverage is poor or scarce, such as in mountainous areas and oceanic regions
Better detection and short range forecasts of heavy rainfall and flash flooding
Ability to monitor the intensity change of tropical cyclones, which is often accompanied by increased lightning activity
Continuity and refinements of lightning climatology within the GOES field of view
GLM Sensor Unit
GLM Sensor Unit (see through)
• Staring CCD imager (1372x1300 pixels)
• Near uniform spatial resolution 8 km nadir, 14 km edge fov