The Cherenkov Telescope Array (CTA) is the next generation ground-based observatory for gamma-ray astronomy at very-high energies which will consist of the northern (CTA-N, La Palma, Spain) and southern (CTA-S, Paranal, Chile) arrays. The atmosphere, as an integral part of the Cherenkov telescope detector, has a great impact on the observed data, especially in means of reduced sensitivity. One...
Aerosol levels influence the wavelength dependent transmission properties of the atmosphere. Variations in aerosol levels therefore affect the amount of Cherenkov light from air showers that can reach an atmospheric Cherenkov detector. As the amount of detected Cherenkov light is directly related to a primary shower particle's energy, deviations between actual and assumed atmospheric...
The Pierre Auger Observatory is detecting ultra-high energy cosmic rays (UHECR) since the early 2000s years in the Pampa Amarilla, Argentina. It is composed of different detection techniques which requires the monitoring of several aspects of atmospheric conditions along with the UHECR detection. We are presenting the multitude of atmospheric monitoring devices and their application in air...
ELVES are regularly being studied since 2013 with the twenty-four FD Telescopes of the Pierre Auger Observatory, exploiting a dedicated trigger and extended readout.
A large fraction of the observed events shows double ELVES within the time window, and, in some cases, even more complex structures are observed. We classify double ELVES using radial variation of the time gap and the photon flux...
The Pierre Auger Observatory is the largest ground-based experiment for the detection of ultra-high energy cosmic rays. In a hybrid approach, many detectors - including radio antennas - observe the extensive air showers induced by cosmic rays. As part of the AugerPrime upgrade, new antennas will be installed on each of the surface detector stations covering a total area of around 3000 km²....
In this talk I will present observations of lightning and terrestrial gamma ray initiation at the Telescope Array (TA) detector. The Telescope Array detector is located in the southwestern desert of the State of Utah. The combination of size and elevation makes it a unique tool that allows us to study thunderstorms. Currently it is the largest ultra high energy cosmic ray experiment in the...
Multiple recent works by the LOFAR lightning team have established the existence of a type of negative leader that emits extremely intense radio radiation. In addition, these leaders propagate about ten times faster than normal negative leaders (10^6 m/s vs 10^5 m/s). We refer to this phenomena as Intensely Radiating Negative Leaders or IRNLs; it is plausible they could be related to...
Serendipitously discovered by the BATSE mission in the nineties, Terrestrial Gamma-ray Flashes (TGFs) represent the most intense and energetic natural emission of gamma rays from our planet. TGFs consist of sub-millisecond bursts of gamma rays (energy up to one hundred MeV) generated during powerful thunderstorms by lightenings and are in general companions of several other counterparts...
We present a full analysis of the seven years of quasi-continuous LIDAR data
taken during those nights when the MAGIC telescopes were operating. Characterization of the nocturnal ground layer yields zenith and azimuth angle dependent aerosol
extinction scale heights for clear nights. We derive aerosol transmission statistics for light emitted from various altitudes throughout the year and...
The Major Atmospheric Gamma-ray Imaging Cherenkov (MAGIC) telescopes are a system of two Imaging Atmospheric Cherenkov Telescopes (IACTs). IACTs make calorimetric use of the Earth’s atmosphere, which allows them to reach large effective areas, but also makes them strongly dependent on the quality of the atmosphere at the time of the observations. Dust intrusions or clouds obscuring the...
Every large world-class observatory must operate in a very dark environment that is as free as possible of anthropogenic sources of light pollution, which can degrade the quality of ground-based astronomical observations. Any LIDAR is able to measure, and subtract from its laser return signals, a corresponding contribution from the night-sky brightness. Our elastic LIDAR system is operated in...
The ARCADE Raman Lidar (RL) has been installed at ORM in October 2018 for the pre-production phase of Cherenkov Telescope Array (CTA). The RL has collected vertical profiles of aerosol optical properties and water vapour two times a day, at sunrise and sunset, in automatic and unattended mode. Although the on-site services have been less than scheduled, mainly because the COVID-19 outbreak,...
Cloud features above the Pierre Auger Observatory (Mendoza Province, Argentina) produce significant effects on the reconstruction of Extensive Air Showers.
In this work, we present seasonal variations of cloud-base height, cloud coverage, and correlation between different sites using the information of elastic multiangle lidar data.
This system locates the presence of clouds by measuring...
The Raman lidar (RL) at the Central (Raman) Laser Facility (CRLF) of the Pierre Auger Observatory in Argentina, has been operational since September 2013.
In this talk, the Auger RL performances are discussed in terms of the data quality for the assessment of the aerosol contribution to the atmospheric UV optical transparency, and how much this is important for the reconstruction of the UHECR...
The Cherenkov Telescope Array (CTA), currently under construction, is the next-generation very-high-energy gamma-ray observatory, providing the coverage for photons in enegy range 20 GeV to 300 TeV. CTA will increase detection sensitivity in the 100 GeV to 10 TeV range for a factor of 5 − 10 with respect to present experiments. It retrieves the properties of very-high-energy gamma-rays by...
The Pierre Auger Observatory is a large-scale experiment for the investigation of ultra-high-energy cosmic rays. A combination of Surface Detector and Fluorescence Detector is used to measure the extensive air showers that are initiated by cosmic ray particles.
Aeolus is a satellite that is operated by the ESA with the purpose of making wind profile measurements on a global scale. To this...
The Telescope Array (TA) experiment detects airshowers induced by ultra high energy cosmic rays. The atmospheric Fluorescence telescopic Detector(FD) observes cosmic ray airshower, which is incident very far from the telescope. The observation does not take place in overcast night. However, the cloud status changes quickly and sometimes there are some isolated clouds. For airshower...
Cosmic radiation is a potential additional tool for atmospheric monitoring. High-energy cosmic rays, interacting in atmosphere, produce secondary particles, the production and propagation of which is ruled by the state of the atmosphere. In particular, atmospheric muons carry information on the stratosphere, as its temperature modulates their intensity.
We present a comprehensive...
The Fluorescence detector Array of Single-pixel Telescopes (FAST) is a design for a next-generation ground-based ultra-high energy cosmic ray observatory, addressing the requirements for a large-area, low-cost detector suitable for measuring the properties of the highest energy cosmic rays with an unprecedented aperture. Three telescope prototypes are installed nearby the fluorescence...
The Southern Wide-field Gamma-ray Observatory (SWGO) is a proposed gamma-ray observatory based on the ground-level particle detection technique, with close to 100% duty cycle and an order of steradian field of view. SWGO will be located in South America at a latitude between 10 and 30 degrees south and an altitude of 4.4 km or higher, covering an energy range from hundreds of GeV to PeV. The...
