Validation of the CUTLASS HF radar gravity wave observing capability using EISCAT CP-1 data

Quasi-periodic ̄uctuations in the returned ground-scatter power from the SuperDARN HF radars have been linked to the passage of medium-scale gravity waves. We have applied a technique that extracts the ®rst radar range returns from the F-region to study the spatial extent and characteristics of these waves in the CUTLASS ®eld-of-view. Some ray tracing was carried out to test the applicability of this method. The EISCAT radar facility at Tromsù is well within the CUTLASS ®eld-of-view for these waves and provides a unique opportunity to assess independently the ability of the HF radars to derive gravity wave information. Results from 1st March, 1995, where the EISCAT UHF radar was operating in its CP-1 mode, demonstrate that the radars were in good agreement, especially if one selects the electron density variations measured by EISCAT at around 235 km. CUTLASS and EISCAT gravity wave observations complement each other; the former extends the spatial ®eld of view considerably, whilst the latter provides detailed vertical information about a range of ionospheric parameters.