Major atmospheric events monitored by deep underground muon data

Abstract

Muon data from the Main Injector Neutrino Oscillation Search (MINOS) underground detector were recently reported to be highly correlated with an effective temperature defined by using a weighting function related to the importance of each level in the stratosphere. During one period of sudden stratospheric warming (SSW), there was a sharp rise in the muon detection rate (and the effective temperature). With a view to studying in more detail the proposed explanation of this sharp rise in the muon detection rate, we have studied a number of other SSW events and in each case found a cooling (or in one case no change) in some part of the stratosphere. This would need to be taken into account in the explanation of the strong correlation between the observed underground muon flux and the upper air temperature.