Equatorial valley region incoherent and coherent scatter measurements at Jicamarca
Abstract
Equatorial valley region ionosphere above Jicamarca has been probed with the 50 MHz ISR system and the VIPIR ionosonde, using multiple receivers and multiple pulsing sequences suitable for the detection of weak incoherent scatter returns amongst strong returns from the equatorial electrojet and 150 km irregularities. Three different IPP's which are multiples of 105 km are used to explore the equatorial mesosphere and the valley region ionosphere with the 50 MHz ISR system while sorting out varying mixes of frequency and range aliasing in the measurements. Short and long IPP (105 and 420 km) coded pulse transmissions with ~5% duty cycle provide sufficient detectability to monitor the incoherent scatter returns from the stable layers of the valley region ionosphere with a 750 m range resolution. A third mode of complementary coded pulse pairs with 150 m baud lengths transmitted at 210 km intervals is utilized for high resolution mapping of the coherent scattering structures found in the mesosphere and the 150 km region. These modes are utilized with spatial and polarization diversity at the receiving stage for mapping out the angle of arrival of the returns and detect the electron density variation of the valley region ionosphere via differential phase and Faraday rotation measurements. Measurements conducted with the Jicamarca ISR beam pointed perpendicular to the geomagnetic field (on-axis direction) are dominated by coherent scattering returns from plasma instabilities, while measurements conducted using an off-perpendicular beam focus on weaker incoherent scatter returns from the region. Observations conducted with either beam detect 150-km returns with oscillatory intensities well correlated with O- and X-mode virtual reflection height oscillations seen in the VIPIR ionograms taken concurrently with the 50 MHZ ISR system. Recent results obtained in August 2018 and July and August 2019 observations at Jicamarca will be presented and discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2019
- Bibcode:
- 2019AGUFMSA43A..04K
- Keywords:
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- 2415 Equatorial ionosphere;
- IONOSPHERE;
- 2431 Ionosphere/magnetosphere interactions;
- IONOSPHERE;
- 6969 Remote sensing;
- RADIO SCIENCE;
- 7944 Ionospheric effects on radio waves;
- SPACE WEATHER