Project Description

In the time span of only a few years since their "discovery", sprites have become one of the most actively researched phenomena in the upper atmospheric physics. What are sprites? Sprites are upper atmospheric optical phenomena associated with thunderstorms. Imagine a lightning originating at altitude ~70 km propagating upward to ionosphere (altitude ~90 km), while extending downward to altitude ~50 km. The vertical extension of sprites can reach ~40-50 km. Instead of a very narrow channel we usually see in a conventional lightning phenomenon, sprites have transverse area ~100 square kilometers. Therefore, the total volume of atmosphere affected by sprites is typically measured in thousands of cubic kilometers at mesospheric/lower ionospheric altitudes above thunderstorms. It appears from space shuttle observations that sprites occur over most regions of the globe (in temperate and tropical areas, over the oceans, and over the land). To date sprites have been successfully detected from ground and airborne platforms in North, Central and South America, in Australia, over winter storms in Japan, and over Europe. The total energy deposited by a typical sprite into the upper atmosphere is estimated to be on the order of 1-10 Mega joules. In spite of the apparently high global occurrence rates, and the rapid progress achieved in recent years in experimental and theoretical studies of sprites, the importance of this fascinating natural phenomenon on the global near Earth thermal and chemical environment is still not quantified. Are sprites only pretty and beautiful like rainbows, or do they significantly impact the atmosphere? This is a very hot topic in the current atmospheric research. Communications and Space Sciences Laboratory at Penn State University is actively involved in development of gas discharge and optical emissions models of sprites in order to answer a broad range of questions related to the microphysics and energy budget of sprites and channels by which their energy is dissipated in the mesospheric and lower ionospheric regions. The REU student will be directly involved in research and software development related to modeling studies of filaments of ionization (so called streamers), which in accordance with recent experimental discoveries constitute small scale building blocks of the large scale sprite phenomena. The basic requirement for this project is to be familiar with C programming language and MATLAB. Some elementary knowledge of electromagnetics is also necessary. This introductory project will provide an excellent opportunity to learn about numerical techniques used in science and engineering for solution of partial differential equations and also will help to master your programming skills.