CRA Seminar: Mahdi Bagheri (University of New Hampshire)

Monte Carlo Simulation and Balloon-Borne Observation of Energetic Radiations and Electromagnetic Fields from Thunderstorms and Lightning

Mahdi Bagheri

Space Science Center and Physics Department, University of New Hampshire

Abstract:

Lightning is one of the most energetic geophysical phenomena, producing the brightest light and loudest sound commonly occurring on Earth. Because of its high rate of occurrence (~ 8 million per day), one might think lightning is well understood, but that is not the case. Lightning’s seemingly random occurrence in space and time and the wide range of its significant time variation, from tens of nanoseconds for many individual processes to more than a second for the total discharge, and its obscuration by the thundercloud producing it makes lightning particularly difficult to study. In this talk, an overview of energetic radiations from lightning (e.g., Terrestrial Gamma-ray Flashes (TGFs), gamma-ray glows and X-rays) will be given. Then, Monte Carlo simulation of gamma-ray flashes from atmosphere of Venus and linear polarization of TGFs will be discussed. In addition, instrumentation of our balloon campaign for detection of gamma-ray glows will be reviewed. The instrumentation includes one BGO scintillator coupled to a Silicone Photomultiplier (SiPM), two Geiger-Muller tubes, and a low-power lightweight Electric Field-Mill sensor, designed and calibrated to measure both polarity and amplitude of electric field inside the thunderstorm region. Finally, some of the preliminary results of balloon launches from Florida into thunderstorm during the summer of 2017 and 2018 will be discussed.