NSF Award
2219663
The Global Electric Circuit (GEC) refers to the continuous movement of atmospheric electricity between the lower atmosphere, ionosphere and magnetosphere, principally driven by lightning. The work that will be conducted under this award will address several unknown or uncertain aspects of the GEC. The importance of the GEC to society is that electric currents in the atmosphere have impacts on communication and aircraft navigation. The project also includes significant training opportunities for the next generation of scientists at a Minority Serving Institution.<br/><br/>The goal of this project is to reduce uncertainties in two major components of the Global Electric Circuit; the upward current from electrified clouds and the downward fair-weather current. To quantify the upward current the research team will examine electric field observations above clouds that were collected from field campaigns over the past three decades, and derive a relationship between those observations and remote sensing measurements such as from the TRMM and GPM satellite missions. Downward fair-weather current would be quantified through electric field observations in Alaska, Colorado, and Texas, with a focus on refining the definition and uncertainties of fair-weather conditions using cloud and aerosol data. Six specific science questions are posed:<br/><br/>• Q#1: In the spectrum of electrified clouds, is it possible to separate the more important clouds having large contributions to the GEC from those that can be neglected, based on properties seen from radar, microwave radiometers, or other satellite-based measurements? What types of electrified clouds supply significant electric current to the GEC? <br/>• Q#2: What is the role of electrified extratropical synoptic systems in the GEC, especially from those with freezing rain and thundersnow? Can their fractional contribution to the GEC be quantified?<br/>• Q#3: Can the estimated current be refined based on the vertical and horizontal structures of the electrified clouds from measurements of radar, passive microwave radiometers, or other satellite-based measurements? <br/>• Q#4: What are the regional, seasonal, and diurnal distributions of the various thunderstorms and electrified shower clouds (ESCs) and their Wilson current contributions to the GEC?<br/>• Q#5: Can the understanding of local influences to surface electric field be improved by using a collection of observations of cloud and aerosols in northern Alaska, and the differences in the diurnal variations of electric fields obtained at other stations? <br/>• Q#6: How would thunderstorms and ESCs in the Arctic vary under a warming climate? How is the local electric field related to the variations of cloud systems in northern Alaska?<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
