The analysis of initial Juno magnetometer data using a sparse magnetic field representation

作者:Moore Kimberly M*; Bloxham Jeremy; Connerney John E P; Jorgensen John L; Merayo Jose M G
来源:Geophysical Research Letters, 2017, 44(10): 4687-4693.
DOI:10.1002/2017GL073133

摘要

The Juno spacecraft, now in polar orbit about Jupiter, passes much closer to Jupiter's surface than any previous spacecraft, presenting a unique opportunity to study the largest and most accessible planetary dynamo in the solar system. Here we present an analysis of magnetometer observations from Juno's first perijove pass (PJ1; to within 1.06R(J) of Jupiter's center). We calculate the residuals between the vector magnetic field observations and that calculated using the VIP4 spherical harmonic model and fit these residuals using an elastic net regression. The resulting model demonstrates how effective Juno's near-surface observations are in improving the spatial resolution of the magnetic field within the immediate vicinity of the orbit track. We identify two features resulting from our analyses: the presence of strong, oppositely signed pairs of flux patches near the equator and weak, possibly reversed-polarity patches of magnetic field over the polar regions. Additional orbits will be required to assess how robust these intriguing features are. Plain Language Summary We analyze magnetic field data from the NASA Juno spacecraft's first orbital pass around Jupiter. Juno passes almost 10 times closer to Jupiter than any previous spacecraft, providing a unique look into the planet's physics. We use a new math technique to model the field near the orbit, providing a high-resolution enhancement to existing models in the regions where we have new data from the Juno Mission. The results have implications for the solid/rocky core of Jupiter, and the physics of how Jupiter generates its magnetic field.

  • 出版日期2017-5-28