The investigators will coordinate operations between the Kodiak High Frequency (HF) radar and the Advanced Modular Incoherent Scatter Radar (AMISR) in Alaska for the purpose of investigating the factors that affect the spectral width of HF radar coherent ionospheric backscatter as observed by the Super Dual Auroral Radar Network (SuperDARN). The two radars will probe a common ionospheric volume. AMISR (together with atmospheric modeling) will provide data on the ionsopheric conditions in the scattering volume: electron density, electron, ion and neutral temperature, electrical conductivities, current, and field, as well as heating rates and ionization rates. Kodiak will operate in two modes, the SuperDARN common mode and a special high spatial and temporal resolution mode made possible by improvements to the Kodiak transmitters. In the common mode, Kodiak will gather data that is comparable to the other SuperDARN radars. In the mode using special pulse compression methods, Kodiak will gather data on shorter time scales and on smallers spatial scales than in the common mode. The data will be analyzed to determine environmental conditions and sub-integration period or sub-range gate length variations in the scatter process that affect the common mode spectral width. The backscatter spectral width is one of the three quantities calculated from the HF radar coherent backscatter spectrum: total backscattered power, mean Doppler velocity, and spectral width. The spectral width has been shown by several studies to be useful for the purpose of identifying the ionospheric projection of magnetospheric regions and boundaries: the cusp, the low latitude boundary layer, and the open-closed magnetic field line separatrix. The latter is very important since a means to track the open-closed field line separatrix is necessary for measurements of the magnetospheric reconnection rate. However, there is currently no accepted theoretical explanation for the variations of the spectral width that identify these regions and boundaries. This project will provide precise data on which to base a theory of the spectral width so that the information contained in the spectral width data may be properly interpreted. The results of this project will enable better measurement of the magnetospheric reconnection rate and consequent improvement in space weather forecasting with tangible benefits for the aerospace industry and society at large. This project will also integrate research and education by advancing discovery and understanding while at the same time promoting teaching, training, and learning by employing at least two and probably three undergraduate physics majors as research assistants. This award is co-funded by EPSCOR because it is collaborative in nature between two EPSCOR jurisdictions (Louisiana and Alaska).
