16:15 〜 16:30
[PPS05-09] Mercury's magnetotail twist: Predicting MPO and Mio observations
キーワード：Mercury, Magnetosphere, BepiColombo, Numerical Modeling
Previous studies have reported magnetotail twisting in several planetary magnetospheres in the solar system.
Such twisted tails may be the result of magnetic reconnection between the Interplanetary Magnetic Field (IMF) and the planetary intrinsic magnetic field.
In particular, MESSENGER Magnetometer observations of the nightside current sheet reveal the near magnetotail of Mercury presents a very small twist (up to 3 degrees), despite the Hermean magnetosphere being continuously driven by reconnection.
However, given that the influence of the planetary magnetic field weakens as the downtail distance increases, an increasing tail twist could be expected, depending on the IMF direction.
In this study, we conduct multiple global 3D hybrid simulation runs for 14 different IMF directions and compare the degree of tail twist at altitudes covered by MPO, MESSENGER, and Mio.
Our results indicate a strong downtail dependency of the location of the X-line, the lobe field configuration, and the tail twist on the IMF orientation.
In addition, we also find that magnetic field observations along certain nightside orbits of MPO and Mio show a strong correlation with the IMF, therefore, we suggest these observations could be used to provide a proxy for the upstream IMF polarity.
Such twisted tails may be the result of magnetic reconnection between the Interplanetary Magnetic Field (IMF) and the planetary intrinsic magnetic field.
In particular, MESSENGER Magnetometer observations of the nightside current sheet reveal the near magnetotail of Mercury presents a very small twist (up to 3 degrees), despite the Hermean magnetosphere being continuously driven by reconnection.
However, given that the influence of the planetary magnetic field weakens as the downtail distance increases, an increasing tail twist could be expected, depending on the IMF direction.
In this study, we conduct multiple global 3D hybrid simulation runs for 14 different IMF directions and compare the degree of tail twist at altitudes covered by MPO, MESSENGER, and Mio.
Our results indicate a strong downtail dependency of the location of the X-line, the lobe field configuration, and the tail twist on the IMF orientation.
In addition, we also find that magnetic field observations along certain nightside orbits of MPO and Mio show a strong correlation with the IMF, therefore, we suggest these observations could be used to provide a proxy for the upstream IMF polarity.