Lightning Characteristics Associated with Atmospheric Rivers Affecting the Continental United States Using the GOES-16/17 Geostationary Lightning Mappers

Atmospheric rivers (ARs) are narrow, elongated, synoptic jets of water vapor that play important roles in the global water cycle and regional weather/hydrology. ARs have long been recognized as the major precipitation deliverers, flood producers, and drought busters in the western US. On the other hand, the presence and impacts of ARs in inland and east coast areas are only starting to get recognized. The recently launched GOES-16 and 17 satellites – centered over eastern and western US, respectively – provide opportunities for studying ARs across the US at unprecedented spatiotemporal resolutions. In particular, the Geostationary Lightning Mapper (GLM) aboard each of the two satellites is the first operational lightning mapper in geostationary orbit. Motivated by the limited number of observational studies for ARs across the entire US and taking advantage of the newly available GLM observations, we will investigate AR footprints and impacts on lightning rate (a yet-to-be-studied characteristic of ARs), including their seasonal and geographical variations, across the US. AR detection will be based on a validated detection algorithm applied to integrated water vapor transport from the MERRA-2 reanalysis. The climatological relationship between ARs and lightning, and between lightning and intense precipitation in narrow cold-frontal rainbands, will be examined. The potential connection between offshore lighting and extreme precipitation later onshore during AR landfalls will be explored. The study will help demonstrate the unique value of the GOES-16/17 capabilities for monitoring/characterizing ARs and their impacts.