Previously Unreported Emissions from Ionospheric Heating Experiments

Mutiso, C.1, Hughes, J.1, Kosch, M.2 and Gustavsson, B.3

1 Embry-Riddle Aeronautical University, Daytona Beach, USA
2 Lancaster University, Lancaster, UK
3 Swedish Institute of Space Physics, Kiruna, Sweden

We present observations of the O+ 732 nm multiplet emission (excitation energy ~5.00 eV) generated during an ionospheric heating campaign conducted in March 2007 at HIPAS, Alaska. The emission, which to the best of our knowledge has not been previously observed during ionospheric heating experiments, was detected along the local magnetic zenith during cycles of O-mode heating at the second gyro harmonic (2.85 MHz). In addition to the brighter OI 557.7 nm (4.17 eV) and 630.0 nm (1.96 eV) features, other emissions of interest observed were the OI 777.4 nm and 844.6 nm lines, both with excitation energies of ~11 eV.

The primary instrumentation used was a modified Czerny-Turner CCD spectrometer observing from 500 to 860 nm. In addition, there were several co-located all sky cameras. Radar diagnostics were provided by the Kodiak Island HF SuperDARN radar, and the AMISR VHF radar located at Poker Flat. Optical, radar, model and ionosonde data will be analyzed in an attempt to characterize this previously undetected emission.