Preface

Abstract

AtmoHEAD (ATmospheric Monitoring for High Energy Astroparticle Detectors) is a periodic 3-days international workshop on the influence of the atmosphere on high-energy cosmic-ray and gamma-ray astroparticle detectors. The 2022 edition is focused on atmospheric monitoring and on the detection and study of events related to atmospheric electricity. The event follows the tradition of previous AtmoHEAD conferences - AtmoHEAD 2013 in Saclay, 2014 in Padova, 2016 in Olomouc and 2018 in Anacapri.The atmosphere is an integral component of many high-energy astroparticle detectors. These include Imaging Atmospheric Cherenkov Telescopes (IACTs) and ground or space based cosmic-ray extensive air shower detectors. All these observatories use the atmosphere as a giant calorimeter where cosmic rays and gamma rays deposit their energy and initiate extensive air showers; it is also the medium through which the resulting Cherenkov and Fluorescence light propagates, and through which it is attenuated and scattered before reaching the detectors. Clearly, a precise and quantitative monitoring of the atmospheric aerosol and molecular conditions are mandatory for an accurate reconstruction of the detected events. Moreover, in the last years there is a growing interest in the detection of electrical phenomena (ELVES, TGFs, ...) developed in atmosphere with high-energy astroparticle detectors, which represent a unique opportunity to study the characteristics of these events with large statistics and precision.New and common monitoring and calibration instruments including lidars, distant laser facilities, cloud monitors, all sky cameras, sun/moon photometers, satellite observations, lightning sensors, as well as simulations, are among the most important tools of these observatories.These online workshop proceedings are grouped in two main sections, Atmospheric Characterization and Atmospheric Electricity and focus on the state-of-the-art and future perspectives of techniques and instruments.Some more detail on the topics treated in the workshop :• the influence of the atmosphere on the measurements of present and future UHECR and gamma-ray experiments• terrestrial gamma-ray flashes, transient luminous events and general topics in atmospheric electricity• analysis techniques and instruments• public global data sets, models and simulationsWe take advantage of this preface to thank all the participants for the very fruitful discussions that came up during the workshop in a friendly and collaborative atmosphere, among participants of different but complementary fields. This was the main goal of AtmoHEAD 2022.AtmoHEAD 2022 was organized by the Department of Physics “E. Pancini ” of the University of Napoli Federico II and by the Napoli Division of the National Institute of Nuclear Physics (INFN).