This project will investigate the role of radio waves in the electromagnetic coupling of the magnetosphere to the ionosphere. In particular it will examine auroral hiss and medium frequency bursts (MFB), which appear in the auroral zones as a prompt response to the onset of a magnetic substorm. In addition to the association with substorm onset, auroral radio emissions are associated with a number of other auroral phenomena, such as poleward-moving arcs and increases in radio wave absorption. The project will use a combination of experimental measurement and theoretical and numerical analysis. An important part of the project will be the measurement of full waveforms and fine structure in MFB events. The waveform measurements will be performed at multiple sites and for multiple events. In some cases it will be possible to use incoherent scatter radar data to determine the plasma density structures within the ionosphere that affect the propagation and dispersion of the waves. Statistical analysis of MFB events, in conjunction with conjugate satellite measurements, will be used to determine the nature of electron precipitation associated with the events. The theoretical and numerical analyses will determine whether or not Langmuir and Z-mode waves can explain the mode conversion processes need to explain the generation of medium frequency bursts.
Magnetosphere-ionosphere coupling and magnetic substorms have been identified as central problems to our understanding of near-earth space plasmas. This project will examine the role that auroral hiss and medium frequency wave bursts play in M-I coupling. Both graduate and undergraduate students will participate in this project in all aspects of the research, including the development of wave measurement instruments, the deployment of the instruments, the analysis of the data obtained from the instruments and the related plasma theory. The majority of the research will take place at Dartmouth College and will offer opportunities for first and second year women to participate in the research through the Dartmouth Women-in-Science Program (WISP).
