HR: 0800h
AN: SA31A-0333    [Abstracts]
TI: Comparison of Optical and Total Electron Content (TEC) Measurements in Polar Cap Patches
AU: * Pedersen, T
EM: todd.pedersen@hanscom.af.mil
AF: Air Force Research Laboratory, AFRL/VSBXI 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Wellman, T
EM: twellman@mac.com
AF: Northwest Research Associates, AFRL/VSBXI 29 Randolph Road, Hanscom AFB, MA 01731 United States
AU: Carrano, C
EM: charlie@radex.com
AF: AER Inc., 131 Hartwell Avenue, Lexington, MA 02421 United States
AB: Plasma densities in the ionospheric polar cap are often extremely structured over the entire range of spatial scales. Polar cap patches represent the dominant structures in the scale range of 100-1000 km, and are typically associated with increased irregularities at the 100-1000 meter scale responsible for scintillation of radio signals. The horizontal structuring of F-region ionization at any scale is difficult to determine in two dimensions due to the lack of plasma measurement techniques that are both sufficiently direct and cover large horizontal areas. We have carried out numerous comparisons of 630.0 and 777.4 nm all-sky optical images and line-of-sight TEC measurements in the polar cap to determine the correspondence between observed optical structure and plasma density, and to interpolate between widely spaced TEC measurement points. Optical images from periods when high correlations exist between optical emission intensity and slant TEC can be used to unambiguously examine the structure of the plasma in 2 dimensions over large areas at a variety of scale sizes. We have determined the typical scale sizes, elongation ratios, and orientation relative to the noon-midnight and dominant flow axes for a large number of polar cap patches, and found cases of extreme elongation in some structures. Further application of the optics-TEC correlation process may allow generation of high-resolution all-sky maps of TEC for use in mitigating space weather impacts on affected systems.
DE: 0310 Airglow and aurora
DE: 2475 Polar cap ionosphere
DE: 2776 Polar cap phenomena
DE: 6934 Ionospheric propagation (0689, 2487, 3285, 4275, 4455)
SC: SPA-Aeronomy [SA]
MN: Fall Meeting 2005