A Holistic Approach to the SMILE Mission and SMILE Public Engagement.

Here we consider initial steps of how upcoming data from the SMILE Soft X-ray Imager and Ultraviolet Imager may be combined with additional data sources to provide a more holistic view of the coupled magnetosphere-ionosphere system. The Ground-based and Additional Science Working Group aims to embed SMILE in a multi-scale and holistic view of the Earth's magnetosphere by exploring coordination of ground-based and other spacecraft's data with SMILE. This working group is one of four working groups within the SMILE Science Working Team who are tasked with preparing all aspects of the mission. Adequate preparation is essential to optimise the tools, multiple instrument campaigns and procedures to allow the maximum science return from SMILE in the context of the entire available range of temporal and spatial scales in the terrestrial system. SMILE instruments will not work in isolation from each other, nor from other spacecraft or ground-based experiments. Synergies with other missions and ground-based experimentation will be fundamental for full science exploitation of the data. In this paper, we expand on the previous publications by the Ground-Based and Additional Science working group, by exploring the possibilities of using a two-way approach to deriving scientific results from SMILE, using a small isolated substorm as a case study. We use knowledge of the contemporaneous solar wind conditions during the substorm to simulate SMILE Soft X-ray Imager data. We also use observed ultraviolet auroral emissions and field-aligned current data as measured in the high-latitude polar regions to act as either a proxy for the SMILE Ultraviolet Imager, or an alternative source of information for the open-closed field line boundary. The observational data is used to constrain the minimisation of the two-dimensional X-ray images, leading to an improvement in the derived shape of the flank magnetopause position. We also comment on mission's possibilities to inspire the public through various engagement programmes, and current activities to involve diverse communities in the preparations and science exploitation of SMILE.