# AtmoHEAD: Atmospheric Monitoring for High-Energy Astroparticle Detectors

10-12 June 2013
CEA Saclay
Europe/Paris timezone

## Determining atmospheric aerosol content with an infra-red radiometer

10 Jun 2013, 14:45
30m
Galileo Room, Building 713C (CEA Saclay)

### Galileo Room, Building 713C

#### CEA Saclay

France
Talk Monitoring facilities in operation

### Speaker

Dr Michael Daniel (University of Liverpool)

### Description

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 the aerosol contribution of the measured sky brightness temperature at the H.E.S.S. site; compare it to effective changes in the telescope trigger rates; and discuss how it can be used to provide an assessment of sky clarity that is unambiguously free of telescope systematics.

### Primary author

Dr Michael Daniel (University of Liverpool)

 Slides