Context. Jovian electrons serve an important role in test-particle distribution in the inner heliosphere. They have been used extensively in the past to study the (diffusive) transport of cosmic rays in the inner heliosphere. With new limits on the Jovian source function, that is, the particle intensity just outside the Jovian magnetosphere, and a new set of in-situ observations at 1 AU for cases of both good and poor magnetic connection between the source and observer, we revisit some of these earlier simulations. Aims. We aim to find the optimal numerical set-up that can be used to simulate the propagation of 6 MeV Jovian electrons in the inner heliosphere. Using such a setup, we further aim to study the residence (propagation) times of these particles for different levels of magnetic connection between Jupiter and an observer at Earth (1 AU). Methods. Using an advanced Jovian electron propagation model based on the stochastic differential equation approach, we calculated the Jovian electron intensity for different model parameters. A comparison with observations leads to an optimal numerical setup, which was then used to calculate the so-called residence (propagation) times of these particles. Results. Through a comparison with in-situ observations, we were able to derive transport parameters that are appropriate for the study of the propagation of 6 MeV Jovian electrons in the inner heliosphere. Moreover, using these values, we show that the method of calculating the residence time applied in the existing literature is not suited to being interpreted as the propagation time of physical particles. This is due to an incorrect weighting of the probability distribution. We applied a new method, where the results from each pseudo-particle are weighted by its resulting phase-space density (i.e. the number of physical particles that it represents). We thereby obtained more reliable estimates for the propagation time.

Context. Jovian electrons serve as an important test-particle distribution in the inner heliosphere and have been used extensively in the past to study the (diffusive) transport of cosmic rays in the inner heliosphere. With new limits on the Jovian source function (i.e. the particle intensity just outside the Jovian magnetosphere), and a new set of in-situ observations at 1 AU for both cases of good and poor magnetic connection between the source and observer, we revisit some of these earlier simulations. Aims. We aim to find the optimal numerical set-up that can be used to simulate the propagation of 6 MeV Jovian electrons in the inner heliosphere. Using such a set-up, we further aim to study the residence (propagation) times of these particles for different levels of magnetic connection between Jupiter and an observer at Earth (1 AU). Methods. Using an advanced Jovian electron propagation model based on the stochastic differential equation (SDE) approach, we calculate the Jovian electron intensity for different model parameters. A comparison with observations leads to an optimal numerical set-up, which is then used to calculate the so-called residence (propagation) times of these particles.Results. Comparing to in-situ observations, we are able to derive transport parameters that are appropriate to study the propagation of 6 MeV Jovian electrons in the inner heliosphere. Moreover, using these values, we show that the method of calculating the residence time applied in former literature is not suited to being interpreted as the propagation time of physical particles. This is due to an incorrect weighting of the probability distribution. We propose and apply a new method, where the results from each pseudo-particle are weighted by its resulting phase-space density (i.e. the number of physical particles that it represents). Thereby we obtain more reliable estimates for the propagation time.

Although the main processes are well known, the transport parameters of charged particles in the inner heliosphere are still under investigation. A newly developed GPU-accelerated code to solve Parker's transport equation by means of stochastic differential equations (SDEs) offers the possibility to perform extensive parameter studies. Investigating electrons originating from the Jovian magnetosphere, we will present the potential of the code as well as first results of the time profile near Earth as a function of varying the solar wind speed, the strength of the diffusion and relation between the parallel and the perpendicular diffusion coefficient.

<p>Galactic cosmic rays (GCRs) consist of energetic electrons and nuclei which are a direct sample of material from far beyond the solar system. Measurements by various particle detectors have shown that the intensity varies on different timescales, caused by the Sun’s activity and geomagnetic variation. Interplanetary disturbances cause space weather effects which warrant a more detailed study. Many studies on GCR intensity decreases is based on the analysis of ground-based neutron monitors and muon telescopes. Their measurements depend on the geomagnetic position, and the processes in the Earth's atmosphere. In order to get a better understanding of the geomagnetic filter over the solar cycle, the Christian-Albrechts-Universität zu Kiel, DESY Zeuthen, and the North-West University in Potchefstroom, South Africa agreed on a regular monitoring of the GCR intensity as a function of latitude, by installing a portable device aboard the German research vessel Polarstern in 2012. The vessel is ideally suited for this research campaign because it covers extensive geomagnetic latitudes (i.e. goes from the Arctic to the Antarctic) at least once per year. Here we present the measurements for different latitude surveys including the periods of solar maximum in 2014 and solar minimum in 2019. </p><p>The Kiel team received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 870405. The team would like to thank the crew of the Polarstern and the AWI for supporting our research campaign.</p>

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