The energetic electrons and ions embedded in Earthward‐moving plasmoid structures have been observed. These plasmoids are associated with a rotational local B_z component (bi‐polar) signature. Energetic electrons are found to be confined in a smaller spatial region than ions inside the plasmoid. Energetic ions and electrons seem to be a good indicator for the structure boundary. The fleet of Cluster spacecraft cross the plasmoid structure in a “first entry, last out” order (Note: when spacecraft cross a planar discontinuity, e.g. magnetopause, they will be in “first entry, first out” order). This documents the fact that the plasmoid has a non‐planar nested structure. The large separation distance (around 1 R_E) of the Cluster satellites in October 2002 is an advantage to provide constraints on the size and shape of the plasmoid structure of interest. In addition, the plasmoid (with closed field lines) should preserve the ion composition information where it is formed. The ion composition observed in the plasmoid shows significantly lower O and He than in the ambient plasma. This implies few heavy ions are involved in the reconnection process where the plasmoid is formed. Multiple flux ropes/plasmoids observation presented in this paper can be interpreted as strong evidence for multiple X‐lines.

We present Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations of a “Spontaneous Hot Flow Anomaly” (SHFA) upstream from the prenoon bow shock at 0431 UT on 12 August 2007. Although the SHFA exhibited the greatly heated and deflected solar wind plasmas used to identify hot flow anomalies (HFAs), it did not result from the standard mechanism invoked for the formation of HFAs, namely the interaction of an interplanetary magnetic field (IMF) discontinuity with the bow shock. We employ THEMIS A, B, C, and D observations to describe the evolution of the event from a proto‐SHFA exhibiting regions of depressed magnetic field strength and density but little evidence for plasma heating or flow deflection, to a well‐developed SHFA further downstream. These observations show that SHFA can be generated without the presence of an IMF discontinuity and are therefore a new category of HFAs.