Wellbrock, A;
Jones, GH;
Dresing, N;
Coates, AJ;
Wedlund, CS;
Nilsson, H;
Sanchez‐Cano, B;
... Mandt, K; + view all
(2022)
Observations of a Solar Energetic Particle Event from Inside and Outside the Coma of Comet 67P.
Journal of Geophysical Research: Space Physics
, 127
(12)
, Article e2022JA030398. 10.1029/2022ja030398.
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Abstract
We analyze observations of an SEP event at Rosetta’s target comet 67P/Churyumov-Gerasimenko during March 6th-10th 2015. The comet was 2.15AU from the Sun, with the Rosetta spacecraft approximately 70km from the nucleus placing it deep inside the comet’s coma and allowing us to study its response. The Eastern flank of an ICME also encountered Rosetta on March 6th and 7th. Rosetta’s RPC data indicate increases in ionization rates, and cometary water group pickup ions exceeding 1keV. Increased charge exchange reactions between solar wind ions and cometary neutrals also indicate increased upstream neutral populations consistent with enhanced SEP induced surface activity. In addition, the most intense parts of the event coincide with observations interpreted as an infant cometary bow shock, indicating that the SEPs may have enhanced the formation and/or intensified the observations. These solar transient events may also have pushed the cometopause closer to the nucleus.We track and discuss characteristics of the SEP event using remote observations by SOHO, WIND and GOES at the Sun, in-situ measurements at STEREO A, Mars and Rosetta, and ENLIL modeling. Based on its relatively prolonged duration, gradual and anisotropic nature and broad angular spread in the heliosphere, we determine the main particle acceleration source to be a distant ICME which emerged from the Sun on March 6th 2015 and was detected locally in the Martian ionosphere but was never encountered by 67P directly. The ICME’s shock produced SEPs for several days which traveled to the in-situ observation sites via magnetic field line connections.
| Type: | Article |
|---|---|
| Title: | Observations of a Solar Energetic Particle Event from Inside and Outside the Coma of Comet 67P |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1029/2022ja030398 |
| Publisher version: | https://doi.org/10.1029/2022ja030398 |
| Language: | English |
| Additional information: | This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
| Keywords: | Comets, Ionospheres, Planetary bow shocks, Energetic particles, Interactions with solar wind plasma and fields, Coronal mass ejections |
| UCL classification: | UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics UCL > Provost and Vice Provost Offices > UCL BEAMS UCL |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10158159 |
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