Cosmic ray flux depends on altitude.

During this period the cosmic ray flux on Earth would increase by a factor of 1000.

The cosmic ray flux varies and the different materials around the laboratory can produce very different amounts of background neutrons from one place to another.

However, the strength of the solar wind is not constant, and hence it has been observed that cosmic ray flux is correlated with solar activity.

In the past, it was believed that the cosmic ray flux remained fairly constant over time.

However, recent research suggests 1.5 to 2-fold millennium-timescale changes in the cosmic ray flux in the past forty thousand years.

As a consequence, the cosmic ray flux in the inner solar system is anticorrelated with the overall level of solar activity.

Dedicated ground-level neutron detectors, namely neutron monitors, are employed to monitor variations in cosmic ray flux.

Firstly, while sunspot activity declined after 1985, cosmic ray flux reached a minimum in 1992 and contributed to warming during the 1990s.

As a result, cosmic ray fluxes within the heliopause are inversely correlated with the solar cycle.