Lawrence Wiencke
(Colorado School of mines)
10/06/2013 09:45
The earth’s atmosphere offers an enormous detector for cosmic rays. Without it, high energy particles could not generate air showers accompanied by profiles of detectable light. But once the light is created, these photons encounter a dynamic time-dependent medium through which they must propagate to reach the detector focal surface(s). Unraveling this process is a critical puzzle of a rich...
Dr
Laura Valore
(Universita' di Napoli Federico II)
10/06/2013 11:10
The Fluorescence Detector (FD) of the Pierre Auger Observatory provides a nearly calorimetric measurement of the primary particle energy, since the fluorescence light produced is proportional to the energy dissipated by an Extensive Air Shower (EAS) in the atmosphere.
The atmosphere is therefore assimilable to a giant calorimeter, whose properties need to be well known during data taking....
Dr
Takayuki Tomida
(RIKEN)
10/06/2013 11:40
Atmospheric monitoring is very important for the observation of air showers by the airfluorescence technique.
In the Telescope Array (TA) experiment, the LIDAR (LIght Detection And Ranging) system and the CLF (Central Laser Facility) system are used for the measurement of atmospheric transparency. The LIDAR system is located southeast of TA site, and the CLF is located in the center of the...
Michael Connolly
(NUI Galway)
10/06/2013 12:10
The stereoscopic Imaging Atmospheric Cherenkov Telescope array of VERITAS, situated at the F.L. Whipple Observatory administrative complex at the foot of the Santa Rita Mountains in southern Arizona, operates in the energy range between 100 GeV and 30 TeV.
The VERITAS collaboration engages in wide-ranging scientific and observational programs in the areas of galactic and extra-galactic...
Dr
Dusan Mandat
(Institute of Physics of Academy of Science of The Czech Republic)
10/06/2013 13:45
The All Sky Camera (ASC) was developed as an universal device for a
monitoring of the night sky quality and night sky background
measurement. ACS system consists of an astronomical CCD camera, a fish
eye lens, a control computer and associated electronics.
The measurement is carried out during astronomical twilight. The
analysis results are the cloud fraction (the percentage of the...
George Vasileiadis
(LUPM)
10/06/2013 14:15
We present an overview of a Elastic Lidar installed on the HESS site. Been in operation for the last 3 years, we will present the state of the analysis and correlation obtained in conjuction with the Hess central trigger data. Possible interpretaion and future plans will also be presented
Dr
Michael Daniel
(University of Liverpool)
10/06/2013 14:45
The attenuation of atmospheric Cherenkov photons is dominated by two processes: Rayleigh scattering from the molecular component and Mie scattering from the aerosol component. Aerosols are expected to contribute up to 30 Wm$^{-2}$ to the emission profile of the atmosphere, equivalent to a difference of ~20C to the clear sky brightness temperature under normal conditions. Here we investigate...
Dr
Markus Gaug
(Universitat Autònoma de Barcelona)
10/06/2013 15:15
The MAGIC telescopes are a system of two dishes operating stereoscopically for ground-based gamma-ray astronomy at the TeV since 2004. The energy and flux reconstruction in this kind of experiment, is substantially affected by the atmospheric conditions, specially by the presence of aerosols and clouds. For atmospheric monitoring, MAGIC hosts different subsystems: a single-channel...
Dr
Konrad Bernlöhr
(MPIK Heidelberg)
10/06/2013 16:15
In Monte-Carlo simulations of detector arrays on the ground (here mainly arrays of Cherenkov telescopes), the atmosphere enters in several ways: in the development of the particle showers, in the
emission of light by shower particles, and in the propagation of
Cherenkov light (or fluorescence light or of particles) down to
ground level. Relevant parameters and their typical impact...
Dr
Bianca Keilhauer
(Karlsruhe Institute of Technology)
10/06/2013 17:00
Extensive air showers initiate the fluorescence emissions from nitrogen molecules in air. The UV-light is emitted isotropically and can be used for observing the longitudinal development of extensive air showers in the atmosphere over many kilometers. This measurement technique is well established since it has been used since many decades by several cosmic ray experiments. However, a...
Joshua Colombi
(LPSC, CNRS/IN2P3, UJF-INPG)
10/06/2013 17:30
When cosmic rays enter the atmosphere, they induce extensive air showers composed of secondary particles. Charged particles excite atmospheric nitrogen molecules, and these molecules then emit fluorescence light in the 300-400 nm range. In cosmic ray observatories as the Pierre Auger Observatory or Telescope Array, the atmosphere is used as a giant calorimeter, where the fluorescence light is...
Dr
Sam Nolan
(Durham University)
11/06/2013 09:30
The current generation of imaging atmospheric Cherenkov telescopes are allowing the sky to be probed with greater sensitivity than ever before in the energy range below and around 100 GeV. To minimize the systematic errors on derived fluxes a full calibration of the atmospheric properties is important given the calorimetric nature of the technique. In this talk we will recount an approach used...
Dr
Cameron Rulten
(Observatoire de Paris)
11/06/2013 10:00
The Cherenkov Telescope Array (CTA) will be the world's first observatory for detecting gamma-rays from astrophysical phenomena and is now in its prototyping phase with construction expected to begin in 2015/16. In this talk we will discuss the detailed simulation studies performed to assess the need for atmospheric monitoring and the methods by which correction for atmospheric variation may...
Raphaël Chalmé-Calvet
(LPNHE)
11/06/2013 11:00
The H.E.S.S. cameras require a precise and regular calibration over time, to reconstruct the gamma-ray characteristics. The different sub-systems used to determine the gain and the uniformity of the PMTs and their evolution with time are presented. Then, we focus on the absolute energy scale calibration, by using a full reconstruction of isolated muons recorded during normal observation, which...
Dr
Pablo Ristori
(Lidar Division - CEILAP (CITEDEF-CONICET))
11/06/2013 11:30
The present work presents monthly statistics of satellite aerosol measurements over the H.E.S.S. site analyzing their seasonal trends during the period 2000 – 2013. Basic changes in the aerosol load distribution mainly correspond to biomass burning transport. It is known that large retrieval uncertainties over land can be expected depending on variable land cover and complex topography...
Dr
Giuseppe Leto
(INAF-Catania Astrophysical Observatory), Dr
Maria Conettta Maccarone
(INAF - IASF Palermo)
11/06/2013 12:00
ASTRI ("Astrofisica con Specchi a Tecnologia Replicante Italiana") is a Flagship Project financed by the Italian Ministry of Education, University and Research, and lead by the Italian National Institute of Astrophysics, INAF. Primary goal of the ASTRI project is the design, development and construction of an end-to-end prototype of a Small Size Telescope for the CTA (Cherenkov Telescope...
Dr
Markus Gaug
(Universitat Autònoma de Barcelona)
11/06/2013 15:00
We investigate the performance of the MAGIC telescopes under three simulated atmospheric conditions: an increased aerosol content in the lower part of the troposphere, the presence of a cloud and an extremely clean atmosphere. We find that the effective area of the telescopes system is gradually reduced in the presence of varying concentrations of aerosols whereas the energy threshold rises....
Michele Doro
(University of Padova and INFN)
11/06/2013 15:05
CTA is an advanced facility for ground-based gamma-ray astronomy in the GeV-TeV regime, currently in the Preparatory Phase. For a correct reconstruction of gamma-ray energies and fluxes, a precise monitoring of the atmospheric transmission is needed. With this aim, the IFAE and UAB institutes are building a specific Raman lidar.
For the optical module, we have foreseen to read-out from the...
Dr
Dusan Mandat
(Institute of Physics of Academy of Science of The Czech Republic)
11/06/2013 15:15
FRAM (F/Photometric Robotic Atmospheric Monitor) is a small optical telescope located at the Pierre Auger Observatory equipped with two CCD cameras with Johnson-Bessel UBVRI filters. We will present its observation program - spanning from the measurements of wavelength dependence of extinction (Angstrom coefficient) using the Landolt fields of standard stars, through the rapid monitoring of...
Dr
Bianca Keilhauer
(Karlsruhe Institute of Technology)
11/06/2013 15:20
A good knowledge of atmospheric parameters is necessary for the reconstruction of air showers, especially with the fluorescence technique. The Global Data Assimilation System (GDAS) provides altitude-dependent profiles of temperature, pressure, humidity and several other state variables. Every three hours, a new data set is available for the entire globe. These GDAS data are now used in the...
Dr
Karim Louedec
(LPSC, CNRS/IN2P3)
11/06/2013 15:25
Aerosols play an important role in the attenuation of UV fluorescence light originated when cosmic rays cross the atmosphere, interacting with the atmospheric nitrogen molecules. This light is recorded by the fluorescence detector (FD) of the Pierre Auger Observatory (www.auger.org), composed of 27 telescopes distributed in 4 stations. In one of these stations, named Coihueco (35° 06’ 52.9’’...
Francois-Marie Breon Breon
(CEA/LSCE)
11/06/2013 15:45
This presentation will describe the various atmospheric monitoring techniques that may be of interest to the Atmohead community :
• Temperature (density) profile of the atmosphere, from the surface and by satellite
• Cloud cover and cloud parameters by satellite
• Aerosol extinction profile by ground-based Lidar
• Aerosol extinction profile by spaceborne Lidar
• Aerosol scattering...
Mario Buscemi
(Università di Napoli "Federico II", ITALY)
11/06/2013 16:45
The characterization of the optical properties of the atmosphere in the near UV, in particular the tropospheric aerosol stratification, clouds optical depth and distribution are common to the field of the physics of the atmosphere, due to aerosol effect on climate, and also to the physics of cosmic rays, for a correct reconstruction of energy and longitudinal development of showers.
The goal...
Dr
Pablo Ristori
(CEILAP (CITEDEF-CONICET), UMI-IFAECI-CNRS (3351))
11/06/2013 17:15
A multi-wavelength scanning Raman lidar is being developed at CEILAP (CITEDEF-CONICET) to monitor the spectral properties of the aerosol extinction in the future CTA Observatory. The reception system of the lidar uses six Newtonian telescopes, with a mirror diameter of 40 cm and a focal length of 1 m. Fused silica optical fibers fix the field of view of the telescopes to 1 mrad and send the...
Dr
Aurelio Siro Tonachini
(Università degli Studi di Torino, ITALY)
12/06/2013 09:30
The elves are transient luminous events triggered by cloud-to-ground lightning return strokes. These events appear as rapidly expanding rings along the lower boundary of the ionosphere, on timescales of the order of 1 ms. The Fluorescence Detectors of the Pierre Auger Observatory can provide 3D imaging of elves with an unprecedented resolution. A dedicated trigger has been designed based on 60...
Dr
Yves BALKANSKI
(IPSL/LSCE)
12/06/2013 10:05
Mineral dust transported form desert areas is ubiquitous in tropical and sub-tropical regions where arid and semi-arid deserts constitute an important source for this natural aerosol. At southern mid- and high-latitudes, the concentrations of mineral dust are less important, but it plays an important role to provide trace metals for phytoplankton in the oceans. The austral region between 40...
stephane vincent
(desy zeuthen)
12/06/2013 11:10
The Cherenkov Telescope Array (CTA) will be the next high-energy gamma-ray
observatory. Selection of the sites, one in each hemisphere, is not obvious since several factors have to be taken into account. Among them, and probably the most crucial, are the atmospheric conditions.
Since July 2012, the site working group has deployed automatic ground based instrumentation (ATMOSCOPE) on all the...
Michele Doro
(University of Padova and INFN)
12/06/2013 11:45
The Cherenkov Telescope Array (CTA) is the next generation of Imaging Atmospheric Cherenkov Telescopes (IACTs). It would reach a sensitivity and an energy resolution never seen before in very high energy gamma-ray astronomy. In order to achieve this goal, the systematic uncertainties derived from the atmospheric conditions shall be reduced to the minimum. Different instruments may help to...
Fred Sarazin
(Colorado School of Mines)
12/06/2013 13:30
The Extreme Universe Space Observatory on board the Japanese Experiment Module (JEM-EUSO) on the International Space Station (ISS) aims at measuring the properties of Extreme Energy Cosmic-Rays (EECRs) by recording their Extensive Air Shower developments in Earth's atmosphere from space. In order to test the good operation of the JEM-EUSO telescope, a network of ground-based Xenon flashers and...
Dr
Simona Toscano
(University of Geneva)
12/06/2013 14:05
The JEM-EUSO observatory on board of the International Space Station (ISS) is a new concept of Space mission devoted to the investigation of Ultra High Energy Cosmic Rays (UHECRs). Looking downward to the Earth atmosphere the JEM-EUSO telescope will detect the fluorescence and Cherenkov UV emission from UHECRs induced Extensive Air Showers (EAS) penetrating in the atmosphere within a 60◦ Field...
M.
Alexandre Boucaud
(APC, université Paris 7 diderot)
12/06/2013 15:45
The LSST is a 8m wide-field photometric telescope that will run at Cerro Pachón in Chile, starting in 2020. As part of the calibration of the 6 large photometric bands ugrizy, there is a need to monitor the atmospheric transmittance in time and across the field of view (~10 deg2). An auxiliary telescope with a spectrometer will be dedicated to that task, fitting an atmospheric model to the...
M.
Trent Grubb
(The University of Adelaide)
Monitoring facilities under development
Talk
Atmospheric cloud cover is an important parameter for many scientific experiments. At the Pierre Auger Observatory the precise locations of clouds, in the field of view of fluorescence detectors, is required to accurately reconstruct the energies and directions of cosmic ray air showers. To improve the current cloud detection system at the Pierre Auger Observatory, Gobi-384 uncooled...
Dr
Michael Prouza
(Institute of Physics - Prague)
Aerosols and interdisciplinary studies
Talk
To select the optimal site for the location of the future Cherenkov Telescope Array project (CTA) for observation of very high energy gamma rays many different data sourced are being analyzed and exploited. In order to obtain the reliable estimate of long-term evolution of the cloud cover above the candidate sites, we have used also the data from geostationary satellites. We will present the...
