Articles | Volume 32, issue 3
Ann. Geophys., 32, 293–300, 2014

Special issue: C/NOFS results and equatorial ionospheric dynamics

Ann. Geophys., 32, 293–300, 2014

Regular paper 28 Mar 2014

Regular paper | 28 Mar 2014

Phase and coherence analysis of VHF scintillation over Christmas Island

E. B. Shume1, A. J. Mannucci1, and R. Caton2 E. B. Shume et al.
  • 1Jet Propulsion Laboratory, California Institute of Technology, Pasadena CA, USA
  • 2Air Force Research Laboratory, Kirtland, NM, USA

Abstract. This short paper presents phase and coherence data from the cross-wavelet transform applied on longitudinally separated very high frequency (VHF) equatorial ionospheric scintillation observations over Christmas Island. The phase and coherence analyses were employed on a pair of scintillation observations, namely, the east-looking and west-looking VHF scintillation monitors at Christmas Island. Our analysis includes 3 years of peak season scintillation data from 2008, 2009 (low solar activity), and 2011 (moderate solar activity). In statistically significant and high spectral coherence regions of the cross-wavelet transform, scintillation observations from the east-looking monitor lead those from the west-looking monitor by about 20 to 60 (40 ± 20) min (most frequent lead times). Using several years (seasons and solar cycle) of lead (or lag) and coherence information of the cross-wavelet transform, we envisage construction of a probability model for forecasting scintillation in the nighttime equatorial ionosphere.