Project Summary

Magnetospheric processes are highly dependent on the solar wind input to the magnetosphere. More precisely, it is the magnetosheath plasma that is in direct contact with the outer magnetospheric boundary, the magnetopause. One of the geo-effective magnetosheath phenomena are localized transient enhancements in density and/or dynamic pressure (called, e.g., jets or plasmoids) that cannot be explained by direct solar wind driving. These jets shall be the subject of the proposed team effort. Their occurrence should not be restricted to the Earth’s magnetosheath. Instead, the phenomenon should be universal, downstream of collisionless shocks.

Recent statistical studies have shown that many of these transients occur downstream of the quasi-parallel bow shock, linking them to processes in the foreshock or at the shock itself. However, statistical findings also imply that different types of jets/plasmoids exist, which feature a range of characteristics and may be associated to a number of different source mechanisms proposed in many case studies. Yet these studies were based on differing definitions of transients, have used varying terminology, methodology, data sets/simulations, and yielded, not unexpectedly, differing results on origin and characteristics of jets. In any case, the jets/plasmoids appear to be plasma entities that flow through an ambient plasma of different characteristics. They share this fundamental property with magnetotail bursty bulk flows, to which they have not been compared to date.

So far, different groups studying jets/plasmoids (including source regions/mechanisms and jet impacts) have been largely disconnected from each other. Consequently, the findings in this field currently resemble pieces of a puzzle rather than a full picture. Our aim is to bring existing and new pieces together in order to construct that picture. We will do so: by compiling a comprehensive review article; by initiating teamwork between researchers familiar with data analysis and simulations, to reconcile findings from both approaches; and by launching inter-disciplinary collaborations to significantly advance our understanding of the nature of jets/plasmoids and bursty bulk flows. In order to achieve these objectives, we bring together a strong team, composed by top tier researchers from 7 different countries. Our team’s combined expertise covers all areas relevant to the proposed research. The team is, hence, in a unique position to overcome present shortcomings of individual approaches to the jet/plasmoid phenomenon.

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