Speaker
Dr
Andriy Zalizovski
(Institute of Radio Astronomy, National Academy of Sciences of Ukraine)
Description
Ionospheric sounding, ozone and geomagnetic measurements were started at Ukrainian Antarctic station (UAS) Akademik Vernadsky (until 1996 British base Faraday) since late 50-th of previous century. The ELF monitoring of global lightning activity as well as Schumann, ionospheric Alfven and magnetospheric resonators were begun at 2000. During last decade we are use the GNSS-TEC technique for estimating the parameters of travelling ionospheric disturbances (TID) manifested in TEC variations. Since 2015 the Doppler sounding of the ionosphere on the UAS-Palmer (located at 54 km far from UAS) radio path aimed at diagnostics of AGW/TID parameters is carried out. And new coherent portable ionosonde of own production was installed at the UAS since March, 2017.
Based on the long-term weather, ozone, geomagnetic and ionospheric monitoring, it was found that both sporadic E layers (Es) and Spread-F effect are dependent on the tropospheric weather mostly at the winter time. For the Spread-F the dependence of repetition frequency on the cyclone activity remains at the September and October inside the ozone hole. The almost linear dependence of Spread-F on the geomagnetic disturbances was found (not so clearly in the winter months). The dependence of Es occurrence frequency on the local K-indexes demonstrates the non-linear character with the maximum at K = 2. This maximum is observed for the Es of cusp-type those located over the maximum of electron concentration of E region and do not observed for low Es. At the winter time the maximum of Es appearance shifts to the local K = 0…1.
The results of diagnostics of TID over the Antarctic Peninsula obtained using two different RF remote sensing techniques are presented. One method is based on multi-positional GNSS TEC measurements. Another is bi-static HF Doppler ionospheric sounding. Several GNSS receivers are located close to the HF diagnostic radio path. Quasi-periodic variations associated with TID were registered simultaneously in both types of data. Significant diurnal and seasonal variations of the TID time period and propagation direction are found. Based on the results of processing, it can be concluded that the TID over the Antarctic Peninsula are usually travelling against the prevailing direction of thermospheric winds.
Summary
Observed plasma irregularities are mostly associated with propagation of large and middle scale atmospheric gravity waves (AGW) at the ionospheric heights.
This work is supported by EOARD-STCU P667 Project.
Primary author
Dr
Andriy Zalizovski
(Institute of Radio Astronomy, National Academy of Sciences of Ukraine)
Co-authors
Dr
Alexander KOLOSKOV
(Institute of Radio Astronomy, National Academy of Sciences, Ukraine)
Prof.
Yuri Yampolski
(Insstitute of Radio Astronomy, National Academy of Sciences, Ukraine)
