Investigation of diurnal variations of cosmic ray fluxes measured with using ASEC and NMDB monitors Original Research Article

A study of daily variations of secondary Cosmic Rays (CR) is performed using data on charged and neutral CR fluxes. Particle detectors of Aragats Space-Environmental Center (ASEC), Space Environmental Viewing and Analysis Network (SEVAN) and neutron monitors of the Neutron Monitor Database (NMDB) are used. ASEC detectors continuously register various species of secondary CR with different threshold energies and incident angles. NMDB joins data of 12 Eurasian neutron monitors. Data at the beginning of the 24th solar activity cycle are used to avoid biases due to solar transient events and to establish a benchmark for the monitoring of solar activity in the new started solar cycle.After eliminating changes associated with atmospheric pressure variations, solar diurnal variations are clearly seen in muon and neutron fluxes. Neutrons daily variations magnitudes, corresponding to the lowest energy primary protons, are comparable with the magnitudes of variations of charged secondary CR. Diurnal variations of neutron flux are higher for the high latitudes comparing with middle latitudes. For low energy muons, the variations are bigger comparing higher energy muons.