EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Diurnal anisotropy of polar neutron monitors, Dome C looks poleward

Agnieszka Gil1, Alexander Mishev2, Stepan Poluianov2, and Ilya Usoskin
Agnieszka Gil et al.
  • 1Institute of Mathematics, Siedlce University, Siedlce, Poland (
  • 2Space Physics and Astronomy Research Unit and Sodankyla Geophysical Observatory, University of Oulu, Oulu, Finland

Galactic cosmic rays (GCR) show a small local anisotropy detected as a diurnal variability of neutron monitor (NM) count rates. As the asymptotic directions of different NMs are diverse, the capability of the GCR diurnal variation observation is also various. Here we present that the Dome C (DOMC) NM is barely sensitive to the diurnal variation. Its amplitude is very small, 0.03%, in comparison to other polar NMs, for which the diurnal variability amplitudes vary from 0.16 to 0.4%. This fact is associated to the narrow asymptotic-direction cone of DOMC NM looking almost to the South pole with geographic latitude above 75o. Thus, DOMC NM is the only existing NM accepting cosmic-ray particles from the off-equatorial region, which makes this station a unique detector.

How to cite: Gil, A., Mishev, A., Poluianov, S., and Usoskin, I.: Diurnal anisotropy of polar neutron monitors, Dome C looks poleward, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1221,, 2022.


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