The Sun dynamically modifies the conditions of the heliospheric environment, with its pressure-driven solar wind (SW) outflow and solar eruptive events, such as solar flares (SFs) and Coronal mass ejections (CMEs), which are the major drivers of space weather effects at the Earth. The magnetic structure and plasma properties of CMEs, as well as their arrival times at L1, however, are hard to predict with reasonable accuracy. In recent decades, advanced instrumentation onboard many spacecraft has extended our ability to explore structures in the SW, such as interplanetary CMEs (ICMEs) and co-rotating interaction regions (CIRs), as well as solar energetic particles (SEPs) from multiple vantage points throughout the heliosphere. It is now also possible to measure and quantify the radiation environment on different planets and to observe Forbush decreases (FDs). The combination of remote sensing, in-situ and ground based observations has led to the development of models that couple solar eruptive events to their effects on a heliospheric scale. Missions including MESSENGER, Venus Express, STEREO, SOHO, Wind, ACE, MAVEN, Rosetta, Ulysses, INTEGRAL, GOES and ground based measurements from Earth (neutron monitors) and Mars (Mars Science Laboratory), coupled with the imminent launches of Solar Orbiter and Parker Solar Probe, as well as potential future missions at L1 and L5, mean it is an opportune time to showcase current developments dealing with such multi-point studies.
Accordingly, we invite abstracts addressing the following topics: multi-point observations of SEPs with regards to their angular distribution, as well as their injection, acceleration, propagation and transport conditions; the latest observational and modeling efforts of the propagation and evolution of ICMEs in the heliosphere; and the use of such ICME properties for the identification of their effects on magnetospheres and on the ground, such as FDs. We welcome contributions on observations, modelling and theory of the SW, CMEs (ICMEs), CIRs, SFs, SEPs and FDs.