Collaborative Research: CEDAR: Flickering and Auroral Roar

United States Air Force Academy, U S A F Academy CO

Investigators

Abstract

This is collaboration between researchers and students at United States Air Force Academy (USAFA) and University of Alaska at Fairbanks' Geophysical Institute (GI). The project is a 2-year multi-instrument observational program to determine the relationship between optical flickering observed in aurora and radio emissions from auroral roars. Optical flickering is common in active discrete arcs. The flickering spots are laterally vibrating columns of luminosity which tend to occur on the bottom edges of auroral arcs. The flicker frequency is typically between 2-20 Hz, with a lifetime of one flickering element of a few seconds. Auroral roar is a band limited radio emission generated in the auroral F-region at frequencies near 2 and 3 times the electron cyclotron frequency. The modulation frequency band is very similar to that of flickering aurora, and even though no connection has yet been made with flickering aurora itself, these types of radio emissions have been named "flickering auroral roar". This project will conduct joint optical and radio observations at Kaktovik Alaska to address the question of the link between flickering in the two types of auroral emissions. At Kaktovik, on the north coast of Alaska, the Geophysical Institute has an optical observatory where flickering aurora is commonly observed. New optical instruments developed at both USAFA and GI will be deployed and operated at Kaktovik. In addition, Dartmouth College currently operates a digital Medium Frequency Interferometer there with support from National Science Foundation (NSF) and collaboration with the principal investigator (PI) on this instrument has been established to provide the radio observations required for this study. The project also will take advantage of a number of already planned rocket launches that will provide in-situ measurements from the upper atmosphere over Kaktovik. Under-graduate cadets from USAFA as well as a graduate student from GI will participate in the project.