Factors Controlling TID Occurrence and Characteristics in Antarctic Peninsula Region
Abstract
Ionospheric HF sounding observations made during 2015-2017 in Antarctic Peninsula region are analyzed with the emphasis on the travelling ionospheric disturbances phenomenology.
Drake Passage in Antarctica generates severe tropospheric disturbances making it a good candidate for studying tropospheric-ionospheric interaction and propagation of the weather disturbances from the ground level to the ionospheric heights. Disturbances in the ionosphere also affect the propagation of the HF radio waves. By measuring the parameters of the ionospherically reflected HF signal it is possible to monitor and to measure the characteristics of TIDs. A dedicated HF sounding system was installed at Palmer and Vernadsky station in 2015 making it possible to collect significant amount of data. Wavelet analysis (i.e., continuous wavelet transform) is used to determine the presence and characteristics of the observed disturbances. The occurrence of the TIDs is directly related to the background ionospheric plasma density, which in turn is controlled by the solar terminator and also affected by the presence of the Weddell Sea Anomaly. Disturbances observed during the nighttime in the Antarctic summer are characterized by longer time periods (40-70 min) in comparison to those observed during the daytime in the winter (15-50 min). Although the observations were made during the solar minimum conditions, the number and intensity of the disturbance observations increased significantly during the geomagnetically active (Kp > 3) conditions. A comparison of the ionospheric disturbance occurrence during geomagnetically quiet times with the wavelike variations in the tropospheric parameters (ground level pressure and wind speed) and also oscillations in the geomagnetic field strength is made. Several cases with the supposed correlation between the variations detected at different regions of the Earth atmosphere are found and presented as the possible evidence of the troposphere-ionosphere interaction.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFMSA33C3495P
- Keywords:
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- 2427 Ionosphere/atmosphere interactions;
- IONOSPHEREDE: 2435 Ionospheric disturbances;
- IONOSPHEREDE: 2437 Ionospheric dynamics;
- IONOSPHEREDE: 2441 Ionospheric storms;
- IONOSPHERE