Comparing LIS and GLD360 Lightning Observations in the western Pacific Ocean Basin

The Lightning Imaging Sensor (LIS) has been deployed on the International Space Station (ISS) for several years. Data from LIS is important to gap-fill in satellite observations of lightning in data-sparse regions such as the western Pacific Ocean, as satellite detection of lightning at present is limited to the GOES-16/GOES-18 footprints of the GLM. In 2023, LIS observations were compared to GLD360 observations available at the National Weather Service (NWS) Weather Forecast Office (WFO) on the island of Guam, the southernmost of the Marianas Islands. A challenge in this comparison is the relative infrequency of lightning strikes in the tradewind environment in which Guam typically sits. Lightning is a bit more frequent when trades collapse and island-effect convection occurs, and when southwesterly flow within the monsoon brings convection over the Marianas . The ISS overflies near Guam at most four times a day, so the number of comparisons is small. However, Guam’s Area of Responsibility (AOR) encompasses the entire western Pacific, from the dateline to the Phillipines. This presentation will document events near Guam and compare the detection efficiencies of the two systems.