First climatology results of equatorial vertical drifts derived from new medium power ISR observations at Jicamarca

The vertical component of equatorial ionospheric plasma drifts is an important feature of the geospace environment at low latitudes. For instance, it controls ionospheric plasma transport and large-scale ionospheric variations at low and mid-latitudes. It also drives ionospheric plasma instabilities responsible for the so-called equatorial plasma bubbles (EPBs).
Despite the importance of the drifts, the incoherent scatter radar (ISR) of the Jicamarca Radio Observatory has been the only ground-based instrument capable of providing equatorial ionospheric plasma drift profiles for many decades now. The Jicamarca ISR measurements, however, utilize large (i.e., MW) transmitters which limit operation to > 40 days per year. More recently, smaller transmitters (i.e., ~ 200 kW) have been installed at Jicamarca and medium power (MP) mode observations of the drifts near F-region peak heights have been successfully obtained. Perhaps more importantly, routine observations (i.e., ~200 days per year) with a standard observation mode started to be made in October 2023.
In this study, we analyzed measurements made with the new MP ISR mode. More specifically, we derive daily height-averaged vertical drift curves. Then, we utilize these curves to create the first results of mean average drifts for different seasons derived from this new MP ISR mode. We highlight that, until now, estimating the seasonal variation of the drifts would require several years of regular ISR measurements. Therefore, measurements would be obtained over a wide range of solar flux conditions.
In this poster, we will describe our approach for processing the MP ISR measurements. We will then present and discuss our results of the mean vertical drifts for different seasons. We will focus, in particular, on how our mean drift curves compare to drifts output by empirical models for similar geophysical conditions. This work contributes with an assessment of the new observational capability at the Jicamarca Radio Observatory.

Acknowledgment: This work was supported by NSF AGS-2215567 and by an NDSEG fellowship (AAM). The Jicamarca Radio Observatory is a facility of the Instituto Geofísico del Perú operated with support from NSF AGS-2213849 through Cornell University.