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Contribution Poster
Variation of the shower lateral spread with air temperature at the ground
Speakers
- Dr. Barbara WILCZYNSKA
Primary authors
- Dr. Barbara WILCZYNSKA (Institute of Nuclear Physics PAN, Krakow, Poland)
Co-authors
- Ralph ENGEL (Forschungszentrum Karlsruhe, Germany)
- Piotr HOMOLA (Institute of Nuclear Physics PAN, Krakow, Poland)
- Bianca KEILHAUER (Universitaet Karlsruhe, Germany)
- Hans KLAGES (Forschungszentrum Karlsruhe, Germany)
- Jan PEKALA (Institute of Nuclear Physics PAN, Krakow, Poland)
- Henryk WILCZYNSKI (Institute of Nuclear Physics PAN, Krakow, Poland)
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Abstract content
The vertical profile of air density at a given site varies considerably with time. Well understood seasonal differences are present, but sizeable effects on shorter time scales, like day to night or day to day variations, are also observed. In consequence, the Moliere radius changes, influencing the lateral distribution of particles in the air showers and therefore may influence the shower detection in surface detector arrays. In air shower reconstruction, usually seasonal average profiles of the atmosphere are used, because local daily measurements of the profile are rarely available. Therefore, the daily fluctuations of the atmosphere are not accounted for. This simplification increases the inaccuracies of shower reconstruction. We show that a universal correlation exists between the ground temperature and the shape of the atmospheric profile, up to altitudes of several kilometers, hence providing a method to reduce inaccuracies in shower reconstruction due to weather variation.
Reference
Proceedings of the 30th International Cosmic Ray Conference; Rogelio Caballero, Juan Carlos D'Olivo, Gustavo Medina-Tanco, Lukas Nellen, Federico A. Sánchez, José F. Valdés-Galicia (eds.); Universidad Nacional Autónoma de México, Mexico City, Mexico, 2008; Vol. 4 (HE part 1), pages 369-372