NMDB workshop 2019

The NMDB workshop will be held in Athens from March 5th till March 7th, 2019.

workshop programme

Scientific contributions

Oral

  • Rolf Bütikofer, Long-term stability of neutron monitor count rates at high altitudes. Today, the worldwide network of neutron monitors (NMs) consists of about 50 NM stations. To investigate the long-term influence of the solar activity on the characteristics of the galactic cosmic rays near Earth based on NM observations, a stable operation of the NM network is of fundamental requirement. In 2007 Bieber et al. have reported that the 1997 peak count rate of the South Pole NM was about 8% lower than the 1965 peak count rate. However, this decrease was not observed at other South polar NM stations. In their investigations Bieber et al. therefore do not rule out ageing of detector tubes as the reason for the decline in the count rate. If this hypothesis is correct, a detector tube ageing effect should also be present e.g. at the NM64 NM Jungfraujoch (JUNG1), because the NM64 NM at Jungfraujoch has the same type of counter tubes and a similar counting rate per tube as the South Pole NM, i.e. 100 cts/second. The presentation compares the count rates of the two NM stations at Jungfraujoch (JUNG and JUNG1) with other NM stations of the worldwide network until 2018.

  • Rolf Bütikofer, SEP events that should be GLEs. Kühl et al. (2017) investigated solar energetic particle (SEP) events with protons accelerated to energies >500 MeV using the data from the Electron Proton Helium Instrument (EPHIN) aboard SOHO in the time interval 1995 – 2015. High latitude, sea level neutron monitors (NMs) detect primary protons with energies >500 MeV. Polar, high altitude NMs (South Pole, Dome C) have even +an atmospheric cutoff energy of only about 300 MeV. Although the investigated SEP events show an increase in the proton flux with energies >500 MeV, some of these SEP events were not detected by the worldwide network of NMs as a GLE. In the list of investigated events by Kühl et al., the SEP event on 9 November 2000 with maximum intensity at 500 MeV protons of >0.1 +(cm2 s sr MeV)^-1 is outstanding as it is not in the official list of GLEs, although the maximum proton flux at 500 MeV is comparable with the SEP events on 14 July 2000 (GLE59) and 15 April 2001 (GLE60). What are the reasons that the SEP event on 9 November 2000 is not a GLE? What can be the contribution of NM data to characterize such SEP events?

  • Christian T. Steigies, The future of NMDB. abstract text

Poster

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