We present long-overdue details about the intensity and spectral characteristics of 150-km echoes observed by the Sao Lu ıs radar in Brazil. The Sao Lu ıs observations show that the echoes usually come from multiple scattering layers that descend in altitude before local noon, and ascend during afternoon ...

This special issue of the Journal of Atmospheric and Solar–Terrestrial Physics on “Recent Advances in Equatorial, Low- and Mid-latitude Aeronomy” contains selected papers presented at the 13th International Symposium on Equatorial Aeronomy (ISEA13). This symposium is the latest in a long series of ...

We present multi-instrumented measurements and multi-technique analysis of polar cap patches observed early during the recovery phase of the major magnetic storm of 20 November 2003 to investigate the origin of the polar cap patches. During this event, the Qaanaaq imager observed elongated polar cap ...

A network of high‐frequency (HF) transmitters and receivers used for ionospheric specification is being installed in Peru. The HF transmitters employ multiple frequencies and binary phase coding with pseudorandom noise, and the observables provided by the receivers include group delay, Doppler shift, ...

We report here on post-midnight uplifts near the magnetic equator. We present observational evidence from digital ionosondes in Brazil, a digisonde in Peru, and other measurements at the Jicamarca Radio Observatory that show that these uplifts occur fairly regularly in the post-midnight period, raising ...