Using EDGE2D-EIRENE to simulate the effect of impurity seeding and fueling on the upstream electron separatrix temperature

•Compared electron separatrix temperature between two point model (TPM) and EDGE2D.•The simulations included varying neon, nitrogen seeding and density.•A factor two variation in EDGE2D electron separatrix temperature (Te) was observed.•The observed electron temperature in EDGE2D was inconsistent with the TPM.•Te was driven by seeding radiation, power crossing separatrix and radial heat flux.