The lightning imaging sensor (LIS) onboard the tropical rainfall measuring mission (TRMM) has significantly enhanced our knowledge of the earth system by providing unique global measurements of…

This federal contract award, valued at $270,209.92, was granted by the National Aeronautics and Space Administration (NASA) to the University of Alabama in Huntsville (UAH) to conduct research on the detection and applications of continuing current in lightning using the Lightning Imaging Sensor (LIS) onboard the Tropical Rainfall Measuring Mission (TRMM) and the upcoming Geostationary Lightning Mapper (GLM) instrument on the GOES-R satellite. The research aims to leverage NASA's space-based optical instruments to identify lightning with continuing current, which is associated with the initiation of forest fires. This work will also explore the characteristics of this type of lightning and its relationship to overall storm development. The award is not designated as a set-aside, and there are no major subcontractors mentioned. The research builds upon NASA's mission to enhance our understanding of the Earth system through the study of global lightning activity.

The lightning imaging sensor (LIS) onboard the tropical rainfall measuring mission (TRMM) has significantly enhanced our knowledge of the earth system by providing unique global measurements of lightning. In particular, this NASA mission has resulted in the most complete map of global lightning activity. Much of the analysis with LIS data to date has focused on flashes. However, there is more information in the data provided by LIS and future instruments, namely groups. A group is a series of spatially contiguous pixels in a single LIS frame, and its closest analog to a lightning process is a stroke. This proposal will explore space-based lightning data in a new and innovative way to meet key NASA objectives. A typical lightning flash is composed of discrete discharges, for discharges that come to ground, the conductive channel that forms and the resulting current flow is referred to as a return stroke. The current in a typical return stroke lasts for hundreds of microseconds, however, there is a class of lightning in which the current in a return stroke can flow for hundreds of milliseconds, known as continuing current. During continuing current, the channel stays luminous. The optical emission can be used to identify lightning with continuing current. While all lightning can be destructive to life and property, lightning with continuing current can be particularly devastating. In particular, this type of lightning is often associated with the initiation of forest fires. Lightning is responsible for 17 percent of wildfires in the united states, yet lightning initiated wildfires represent 62 percent of the burned acreage for the years 2001-2012 (national interagency fire center, 2013). Current research, over a large domain, rarely considers lightning with continuing current. This is primarily due to the lack of instrumentation suited to detect the signature of continuing current. The proposed research will utilize NASA funded, space-based optical instruments to identify lightning that contains continuing current. By using group level data from these instruments, lightning with continuous optical emission can be identified. These can then be correlated with the observation of forest fires from other instrumentation and observations. In addition, initial work suggests there is a class of intracloud lightning that contains continuing current. The proposed work will explore when these flashes occur relative to overall storm development. Initially, historical data from LIS will be used to explore large scale characteristics of lightning with continuing current. Flashes with continuous optical emission will be compared to various ground based network to further detail characteristics of these discharges. The impending launch of LIS on the international space station and the NOAA-NASA geostationary lightning mapper (GLM) on the goes-R satellite in 2016 presents a unique opportunity to further explore this type of lightning. In particular, GLM will be flown in geostationary orbit and will provide hemispheric coverage of total lightning in a time continuous manner. This research initiative will leverage other NASA instruments, namely the moderate resolution imaging spectroradiometer, currently onboard the terra-aqua satellite and the advanced baseline imager, scheduled to be launched on goes-R. This fusion of different NASA instruments will result in earth system science research that will have immediate societal impact. While the proposed research has immediate scientific applications, IT will also allow the PI to establish a research portfolio for a long term research program. Optical measurements of lightning from space will play a prominent role in lightning research in the coming years with the LIS on the ISS and GLM instruments. The proposed work represents a new and unique application of the data these instruments can provide, yielding vital information and research opportunities.