Possible observational evidence of contact discontinuities

Contact discontinuities (CDs) are discontinuities that have the continuous magnetic fields linked between two sides but no plasma flow across their surfaces. Due to a lack of the CDs evidence in observations, their stable existence is still under debate. CDs are not expected to be observed because of rapid plasma diffusion along the magnetic fields across their surfaces. In this study, we propose a feasible procedure with single-satellite data for selecting CD based on MHD jump conditions. We find two CD events, one in the solar wind and another in magnetosphere. The electron temperature is smaller than the ion temperature, and the magnetic pressure is larger than the thermal pressure in both CD events. The widths of the transition in the CD events are estimated to be 4.3 and 11.7 ion gyroradii. These two events might be CDs. Multiple spacecraft analyses are needed for further advancement in this topic.