Solar Modulation

Solar modulation potential based on proton proxies

Data set of monthly solar modulation potential values (1973-2017) derived from 1.28 GV proton proxies IMP-8 He and ACE/CRIS C

An Empirical Modification of the Force Field Approach to Describe the Modulation of Galactic Cosmic Rays Close to Earth in a Broad Range of Rigidities

On their way through the heliosphere, galactic cosmic rays (GCRs) are modulated by various effects before they can be detected at Earth. This process can be described by the Parker equation, which calculates the phase space distribution of GCRs …

Spatial gradients of GCR protons in the inner heliosphere derived from Ulysses COSPIN/KET and PAMELA measurements

*Context.* During the transition from solar cycle 23 to 24 from 2006 to 2009, the Sun was in an unusual solar minimum with very low activity over a long period. These exceptional conditions included a very low interplanetary magnetic field (IMF) …

Galactic cosmic ray quiet time spectra from 300 MeV up to above 1 GeV measured with SOHO/EPHIN

The solar modulation of galactic cosmic rays (GCR) can be studied in detail by long term vari-ations of the GCR energy spectrum (e.g. on the scales of a solar cycle). With almost 20 yearsof data, the Electron Proton Helium INstrument (EPHIN) aboard …

Mini neutron monitor measurements at the Neumayer III station and on the German research vessel Polarstern

Neutron monitors (NMs) are ground-based devices to measure the variation of cosmic ray intensities, and although being reliable they have two disadvantages: their size as well as their weight. As consequence, [1] suggested the development of a …

Simultaneous Analysis of Recurrent Jovian Electron Increases and Galactic Cosmic Ray Decreases

The transport environment for particles in the heliosphere, e.g. galactic cosmic rays (GCRs) and MeV electrons (including those originating from Jupiters magnetosphere), is defined by the solar wind flow and the structure of the embedded heliospheric …

Recurrent modulation of galactic cosmic rays: A comparative study between IMP, SOHO, STEREO, and Ulysses

It is well known that the galactic cosmic ray (GCR) flux is modulated by corotating interaction regions (CIR) in the vicinity of Earth. When Ulysses first explored high latitude regions in 1996, it was found that the flux of GCRs was still modulated …

Modulation of galactic cosmic ray protons and electrons during an unusual solar minimum

During the latest Ulysses out-of-ecliptic orbit the solar wind density, pressure, and magnetic field strength have been the lowest ever observed in the history of space exploration. Since cosmic ray particles respond to the heliospheric magnetic …