The synergy of the cosmic ray and high energy atmospheric physics: Particle bursts observed by arrays of particle detectors

•Most powerful natural particle accelerators that operate in the electrified atmosphere send millions and millions of particles in direction to the earth's surface. The same are doing protons and fully-stripped nuclei accelerated in the most violent explosions in our galaxy and beyond when entering the terrestrial atmosphere and unleashing gigantic particle cascades.•Lightning flashes, in their development phase also generate strong electric fields capable to accelerate electrons. Particle detectors observe a rich variety of short and extended particle bursts that should be scrutinized for the determination of their sources and acceleration mechanisms. Only a multisensory approach joining particle and atmospheric physics instrumentation will allow revealing the physics of particle bursts phenomena. In this paper, we present an approach based on observations made by the largest cosmic ray experiments to explain enigmatic particle bursts usually connected to complicated atmospheric processes.•Multiyear observations made on Aragats cosmic ray observatory give a vast amount of data on particle bursts that can be explained by invoking the extensive air shower development in the atmosphere. Particle bursts detected on the earth's surface during thunderstorms by various particle detectors originated from the relativistic runaway electron avalanches (RREAs) initiated by free electrons accelerated in the strong atmospheric electric fields. Two oppositely directed dipoles in the thundercloud accelerate electrons in the direction of the earth's surface, and to the open space. The particle bursts observed by orbiting gamma ray observatories are called terrestrial gamma ray flashes (TGFs, with energies of several MeV, only sometimes reaching tens of MeV); ones registered by particle detectors located on the ground – are called thunderstorm ground enhancements (TGEs, with energies, usually reaching 40-50 MeV). Balloons and aircraft in the troposphere register gamma ray glows (with energies of several MeV). Recently, high-energy atmospheric physics includes also, so-called, downward TGFs (DTGFs), intense particle bursts with a duration of a few milliseconds. Well-known extensive air showers (EASs) originate from the interactions of galactic protons and fully-stripped nuclei with the atmosphere atoms. EAS particles have very dense cores around the shower axes. However, high-energy particles in the EAS cores comprise a very thin disc of (a few tens of ns), and a particle d