THE STUDY WILL UTILIZE DATA FROM THE MMS SUMMER 2016 PHASE 1X AND 2017-2018 PHASE 2 INTERVALS THAT FOCUS ON THE MAGNETOTAIL AND THEMIS TAIL SCIENCE INTERVALS IN 2010-2015. RECONNECTION AND DIPOLARIZATION FRONT INTERVALS WILL BE IDENTIFIED USING MMS OR THEMIS DATA AND THE IONS IN THE PLASMA SHEET WILL BE ANALYZED USING HPCA FPI ESA AND/OR SST DATA. FOR THE IDENTIFIED INTERVALS DATA FROM THE TWINS ENA INSTRUMENTS WILL BE ANALYZED PROVIDING A GLOBAL PICTURE OF THE ION SPECTRA AND TEMPERATURES IN THE PLASMA SHEET FROM THE MAGNETOTAIL TO THE INNER MAGNETOSPHERE. THUS THE IN SITU MEASUREMENTS WILL BE PLACED IN A GLOBAL CONTEXT AND FEATURES OUTSIDE OF THE VIEW OF MMS/THEMIS WILL BE STUDIED IN RELATION TO THE MEASUREMENTS AT MMS/THEMIS. THE PROPOSED STUDY WILL ADDRESS THE GOALS OF THE MMS TWINS AND THEMIS MISSIONS. THE GOAL OF THE MMS MISSION IS TO REVEAL THE SMALL-SCALE AND THREE-DIMENSIONAL STRUCTURE AND DYNAMICS OF RECONNECTION IN THE MAGNETOSPHERE. THE GOAL OF THE TWINS MISSION IS TO ESTABLISH GLOBAL CONNECTIVITIES AND CAUSAL RELATIONSHIPS AMONG PROCESSES IN DIFFERENT REGIONS OF THE EARTH S MAGNETOSPHERE. THE SPECIFIC FOCUS OF THE TWINS MISSION IS TO IMPROVE OUR UNDERSTANDING OF FUNDAMENTAL PROPERTIES OF GEOSPACE IONS AND GLOBAL DYNAMICS OF INJECTION. THE THEMIS MISSION OBJECTIVES INCLUDE TRACKING THE MOTION OF PARTICLE INJECTION FRONTS THROUGH THE MAGNETOSPHERE TO UNDERSTAND THE VARIATIONS IN THE RADIATION BELTS AND IDENTIFY HOW LOCAL CURRENT DISRUPTION MECHANISMS COUPLE TO THE MORE GLOBAL SUBSTORM PHENOMENA. IMPROVING OUR UNDERSTANDING OF RECONNECTION AND THE ROLE IT PLAYS IN INJECTIONS OF IONS FROM THE MAGNETOTAIL TO THE INNER MAGNETOSPHERE IS ESSENTIAL TO UNDERSTANDING AND BEING ABLE TO PREDICT THE DYNAMICS DURING GEOMAGNETIC STORMS.