Abstract
We present a comparison of the measured cosmic ray (CR) muon fluxes from
two identical detectors at different geolocations and their sensitivity
to space weather events in real time. The first detector is installed at
Mount Wilson Observatory, CA, USA (geomagnetic cutoff rigidity Rc
$\sim$ 4.88 GV), and the second detector is running on
the downtown campus of Georgia State University in Atlanta, GA, USA (Rc
$\sim$3.65 GV). The variation of the detected muon
fluxes is compared to the changes of the interplanetary solar wind
parameters at L1 Lagrange point and geomagnetic indexes. We have also
investigated the muon flux behavior during major interplanetary shock
events and geomagnetic disturbances. To validate the interpretation of
the measured muon signals, the muon fluxes are compared to the neutron
flux measurement from the Oulu neutron monitor (NM) in northern Finland
(Rc $\sim$0.8 GV). The results of this analysis show
that the cosmic ray flux percentage changes from all stations are
significantly correlated with each other and with solar wind parameters
at L1, and the decreases of the muon fluxes can sometimes be observed
several hours ahead of the onsets of the interplanetary shock arrivals
at L1 and geomagnetic disturbances. Although this is yet an initial
effort of building a global network of cosmic ray muon detectors for
monitoring the space and earth weather in real time, the study provides
evidence that muon network detection efficiency can be a diagnostic and
forecasting tool for geomagnetic storms hours before they hit the Earth.