The ESA/NASA Solar Orbiter mission, to be launched in October, 2018, will employ a suite of solar remote sensing and in-situ heliospheric instruments to address a number of top-level science questions including:

a. What drives the solar wind and where does the coronal magnetic field originate from?
b. How do solar transients drive heliospheric variability?
c. How do solar eruptions produce energetic particle radiation that fills the heliosphere?
d. How does the solar dynamo work and drive connections between the Sun and the heliosphere?

UK groups have been active in these and related fields for many years, both through their roles in past and current missions e.g. Ulysses, Cluster, SOHO, Hinode, Stereo, SDO and in advanced theoretical and modelling investigations. The origins of both fast and slow solar wind, their linkage to the heliosphere and the production of energetic particles are also all matters of special interest given current concerns with the impacts of space weather on the near-Earth environment. We invite contributions which explore relevant topics with reference to the existing body of remote sensing solar and in-situ heliospheric data, related scientific synergies and/or to the planning of observations required from Solar Orbiter which would bring about major advances in these fields.

We particularly welcome contributions which relate to the origins of both the fast and slow solar wind with particular reference to the role played by the generation and interaction of magnetic fields and the formation and development of magnetic structures e.g. active regions, filament channels, streamers. Transient events, e.g. flares, CMEs, and the generation of solar energetic particles are also priority topics for the session. In relation to in-situ heliospheric studies, contributions addressing the magnetic structure of the heliosphere and the results of electromagnetic field and wave interactions with the in-situ plasma are of particular interest, as is the consideration of the impacts of transient solar events on the heliosphere. Finally, the discussion would also benefit from contributions addressing the role of the upcoming Solar Orbiter mission and/or the definition of observational strategies to be implemented during the periods of the spacecraft’s close approaches to the Sun. Contributions addressing the unique capability of the Solar Orbiter instruments both to observe solar atmospheric transient phenomena remotely and to register the resulting impacts on the heliospheric plasma and energetic particle populations and magnetic fields are again particularly welcomed.