Browsing by Author "Manay, E."
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Item Open Access Preliminary results of new operation mode JULIA Medium Power at JRO(2023 CEDAR Workshop, 2023-06) Kuyeng, Karim; Scipión, Danny; Condor, P.; Manay, E.; Milla, M.The main radar of the Jicamarca Radio Observatory (JRO), for several years, has operated with two main modes, the ISR mode with big transmitters (1.5 MW), operating around 1000 hours per year, to survey the ionosphere and obtain parameters such as drifts, densities and composition; and the JULIA mode with low power transmitters (20 kW), operating around 4000 hours per year, to measure mostly coherent echoes such as Equatorial Electrojet, Spread F and 150 km echoes to provide with a proxy of the behavior of the ionosphere. Starting in 2022, two new solid-state transmitters were installed at JRO, with peak power of 96 kW each, making it possible to not only detect coherent echoes but to be able to estimate zonal and vertical drifts in the ionosphere too. This new mode, called JULIA Medium Power (JULIA MP), is capable of measuring the same coherent echoes as the original JULIA but able to estimate zonal and vertical drifts up to 500 km. This work will present the preliminary results of this mode, comparisons of the coherent echoes obtained with JULIA and JULIA MP and finally show the quality of drifts we are getting with this medium power mode.Item Open Access The impact of the Hunga Tonga–Hunga Ha’apai volcanic eruption on the Peruvian atmosphere: from the sea surface to the ionosphere(SpringerOpen, 2024-05-28) Pacheco, Edgardo E.; Velasquez, J. P.; Flores, R.; Condori, L.; Fajardo, G.; Kuyeng, Karim; Scipión, Danny; Milla, M.; Conte, J. F.; Poblet, F. L.; Chau, J. L.; Suclupe, J.; Rojas, R.; Manay, E.The eruption of the Hunga Tonga Hunga Ha’apai volcano on 15 January 2022 significantly impacted the lower and upper atmosphere globally. Using multi-instrument observations, we described disturbances from the sea surface to the ionosphere associated with atmospheric waves generated by the volcanic eruption. Perturbations were detected in atmospheric pressure, horizontal magnetic field, equatorial electrojet (EEJ), ionospheric plasma drifts, total electron content (TEC), mesospheric and lower thermospheric (MLT) neutral winds, and ionospheric virtual height measured at low magnetic latitudes in the western South American sector (mainly in Peru). The eastward Lamb wave propagation was observed at the Jicamarca Radio Observatory on the day of the eruption at 13:50 UT and on its way back from the antipodal point (westward) on the next day at 07:05 UT. Perturbations in the horizontal component of the magnetic field (indicative of EEJ variations) were detected between 12:00 and 22:00 UT. During the same period, GNSS-TEC measurements of traveling ionospheric disturbances (TIDs) coincided approximately with the arrival time of Lamb and tsunami waves. On the other hand, a large westward variation of MLT winds occurred near 18:00 UT over Peru. However, MLT perturbations due to possible westward waves from the antipode have not been identified. In addition, daytime vertical plasma drifts showed an unusual downward behavior between 12:00 and 16:00 UT, followed by an upward enhancement between 16:00 and 19:00 UT. Untypical daytime eastward zonal plasma drifts were observed when westward drifts were expected. Variations in the EEJ are highly correlated with perturbations in the vertical plasma drift exhibiting a counter-equatorial electrojet (CEEJ) between 12:00 and 16:00 UT. These observations of plasma drifts and EEJ are, so far, the only ground-based radar measurements of these parameters in the western South American region after the eruption. We attributed the ion drift and EEJ perturbations to large-scale thermospheric wind variations produced by the eruption, which altered the dynamo electric field in the Hall and Pedersen regions. These types of multiple and simultaneous observations can contribute to advancing our understanding of the ionospheric processes associated with natural hazard events and the interaction with lower atmospheric layers.