The dependence of magnetic reconnection on plasmaβand magnetic shear: Evidence from magnetopause observations

摘要: [1] We have performed a statistical study of THEMIS spacecraft crossings the asymmetric dayside magnetopause to test prediction that diamagnetic drift X-line due plasma pressure gradient across can suppress magnetic reconnection. The includes both when reconnection exhausts were present and they absent in current sheet. When we restrict survey subsolar region (10 < MLT < 14), find for low Δβ (the difference β on two sides sheet) majority events occurred over large range shears, whereas was high only shears. Furthermore, nonreconnection primarily Δβ-shear regime which is predicted be suppressed, good agreement with theory. condition should general consequences occurrence space laboratory plasmas.