Observation of a time lag in solar modulation of cosmic rays in the heliosphere

TL;DR

This paper presents evidence of an eight-month time lag in solar modulation of cosmic rays, enabling improved forecasting of cosmic ray fluxes at Earth based on solar activity monitoring.

Contribution

The study introduces a data-driven model revealing a time lag in cosmic ray modulation, enhancing predictive capabilities for cosmic ray fluxes at Earth.

Findings

Identified an eight-month time lag in cosmic ray modulation.

Validated model predictions with AMS space measurements.

Enabled early forecasting of cosmic ray fluxes.

Abstract

The solar modulation effect of Galactic cosmic rays is a time-dependent phenomenon that is caused by the transport of these particles through the magnetized plasma of the heliosphere. Using a data-driven model of cosmic-ray transport in the heliosphere, in combination with a large collection of data, we report the evidence for a eight-month time lag between observations of solar activity and measurements of cosmic-ray fluxes in space. As we will discuss, this result enables us to forecast the cosmic ray flux at Earth well in advance by monitoring solar activity. We also compare our predictions with the new multi-channel measurements of cosmic rays operated by the AMS experiment in space.