ИСТИНА

Pulsating aurora (PsA) is a quasi-periodic modulation of the emission intensity caused by precipitation of energetic electrons. PsA have an extended shape and consist of separate flickering columns. The dynamics of the PsA structures characterized by fast complex movements of their bright part. The mechanisms of PsA formation are still insufficiently studied, as well as their relationship with relativistic and subrelativistic electrons microbursts. The energy of precipitated electrons can be derived from the minimum altitude of the visible patch measured by two instruments observing the same volume of atmosphere from different places. A system of pulsating auroras stereoscopic observations is developed for the high-latitude observatories Verkhnetulomsky and Lovozero of the Polar Geophysical Institute. The imaging photometers are highly sensitive telescopes based on multi-anode photomultiplier tubes (MAPMTs). The first photometer had been installed at the Verkhnetulomsky observatory on September 2021. It has a 1° angular resolution and possibility to operate in three modes with different temporal resolutions: 2.5 µs, 320 µs, and 41 ms. For the first two modes short waveforms of 128 time samples are recorded (4 records each 5 seconds). The third one is a monitoring continuous measurements. During 2021/2022 season it was operated during 163 nights. On September 2022 it was upgraded to increase a temporal resolution of monitoring mode up to 1 ms. The second telescope is planned to be installed in 2023 in Lovozero observatory and will provide a side observations of the same atmospheric volume in the altitude range of 50–100 km with a spatial resolution of about 2 km. This photometer will allow to measure a vertical distribution of the auroral emissions with high temporal resolution and make it possible to estimate the maximum precipitating electrons energies. The photometers complement the already existing PGI all-sky camera system. The report provides a description of the equipment, examples of measurements for the first and second seasons of work. The work was supported by the Russian Science Foundation grant no. 22-62-00010 (https://rscf.ru/project/22-62-00010/).