Nighttime VHF and GHz scintillations in the East‐Asian sector of the equatorial anomaly

Measurements made during solar maximum years in the East Asian sector of the equatorial anomaly show different seasonal patterns of night‐time scintillation occurrence at 137 MHz at Lunping and 4 GHz at Hong Kong. These seasonal variations are very similar to that observed at the equatorial station in Guam, indicating strong coupling between equatorial and anomaly irregularities. Model computations indicate that the GHz scintillation observed at Hong Kong is much stronger than one would expect based on VHF scintillation measured at Lunping. It is suggested that this might be an indication of strong latitudinal dependence of scintillation in the anomaly region. We also discuss the possible difference in local ionospheric conditions that were responsible for generating GHz scintillation causing irregularities in the anomaly region and at the equator.