ИСТИНА

We discuss a time-averaged model for Mercury’s magnetosphere, using MESSENGER magnetometer data from the first three Mercury years when MESSENGER orbiting around Mercury. Based on a paraboloid of revolution approximation to the magnetospheric shape, the paraboloid magnetospheric model has been tested by fitting of the magnetometer data. The magnetospheric field is the sum of contributions from the planetary dipole field, the magnetopause shielding field, and the field due to the tail current sheet. The model magnetospheric magnetic field is specified by a nine parameters: 1)six dipole field parameters: - the offset of the dipole from the planetary center along the MSO axes: dx, dy, dz, - the dipole tilt, psi, and azimuth, phi, and - the equatorial dipole field strength,Bd. 2)three magnetospheric current system parameters: - the sub-solar magnetopause distance,Rss, - the inner edge (closest approach to the planet) of the current sheet,R2, - the tail field,BT. The paraboloid magnetospheric Mercury model provides an excellent first order fit to the MESSENGER observations, with a root-mean-square misfit of less than 20 nT globally. For some specific orbits the discrepancy between model forecast magnetic field vector and vector magnetic field measurements is less than 10 nT for each component. Residual field strengths are typically less than 50 nT compared with maximum field strengths in the observations of up to 500 nT. The significant (up to 480 km) northward dipole offset previously mentioned by Alexeev et al.[2010]have been supported by orbital phase MESSEBGER observations. The tail current sheet crossing by MESSENGER that could be identified as magnetic field depression region well organized by the plane which also shifted to northward direction relative MSO equatorial plane on the dipole offset, dz.