Comparison of Diffusion Region Proxy Parameters in the Geomagnetic Tail

Parameters derived from direct field measurements and particle distribution functions such as the adiabatic expansion parameter and the Swisdak sqrt(Q) parameter are often used to identify or even define the detection of a reconnection diffusion region in in situ data. We calculate these and other "Proxy" parameters for known diffusion regions in the geomagnetic tail as observed by the MMS spacecraft during the 2017 and 2018 Tail Campaigns and identified using only the field and particle moment measurements directly. The reliability and efficacy of each proxy parameter is then discussed. Commonly held prerequisite conditions such as the value of the plasma β are also calculated and discussed.