Speaker
Description
Neutron monitors (NMs) have been continuously measuring the secondary nucleonic component of the galactic cosmic ray (CR) intensity for more than 70 years. NMs have played a fundamental role in our understanding of: solar modulation, namely significant global and temporal variations in the galactic CR intensity and energy spectra as a function of position inside the heliosphere on long time scales (11-year solar activity cycle, 22-year magnetic polarity cycle); short-term variations such as Forbush decreases, i.e. depressions in the GCR intensity due to effect of interplanetary perturbations; ground level enhancements produced by the arrival of relativistic solar particles (the so-called solar cosmic rays) in the Earth atmosphere. This tutorial provides an overview of neutron monitors measurements and cosmic ray science, focusing on the physical processes in the interplanetary space responsible for CR short-term variations and those favoring the high energy particle acceleration at the Sun.
