SM038-02
Magnetosheath high speed jets observed with Cluster and MMS with near-Earth upstream solar wind monitors
Monday, 14 December 2020: 20:34
Virtual
C Philippe Escoubet1, Jonathan P Eastwood2, Heli Hietala2, Ferdinand Plaschke3, Sergio Toledo Redondo4, Kyoung-Joo Hwang5, Lucile Turc6, Andrew P Dimmock7, Primoz Kajdic8, Robert C Fear9, Huishan Fu10, Jean Berchem11, Stein Haaland12, Malcolm Wray Dunlop13,14, Yulia Bogdanova14, Owen Roberts15, Harri E Laakso16, Arnaud Masson17, Matt Taylor17, Chris Carr18, Iannis S Dandouras19, Andrew Neil Fazakerley20, Rumi Nakamura21, James L Burch22, Barbara L Giles23, Craig Pollock24, Christopher T Russell25, Roy B Torbert26 and Vassilis Angelopoulos27, (1)European Space Research and Technology Centre, Noordwijk Zh, Netherlands, (2)Imperial College London, Physics, London, SW7, United Kingdom, (3)IWF ÖAW, Graz, Austria, (4)University of Murcia, Murcia, Spain, (5)Southwest Research Institute, San Antonio, TX, United States, (6)University of Helsinki, Department of Physics, Helsinki, Finland, (7)IRF Swedish Institute of Space Physics Uppsala, Uppsala, Sweden, (8)National Autonomous University of Mexico, Ciudad DE Armería, Mexico, (9)University of Southampton, Southampton, United Kingdom, (10)Beihang University, Beijing, China, (11)University of California Los Angeles, Department of Physics and Astronomy, Los Angeles, CA, United States, (12)MPS/BCSS, IFT, Bergen, Norway, (13)Beihang University, School of Astronautics, Beijing, China, (14)Rutherford Appleton Laboratory, Didcot, United Kingdom, (15)IWF Institute for Space Research, Graz, Austria, (16)ESA/ESAC, Villanueva de la Cañada, Spain, (17)European Space Agency, Villanueva De La Can, Spain, (18)Imperial College London, London, United Kingdom, (19)IRAP, Toulouse, France, (20)Mullard Space Science Lab., Dorking, United Kingdom, (21)Space Research Institute, Graz, Austria, (22)Southwest Research Institute San Antonio, San Antonio, TX, United States, (23)NASA Goddard Space Flight Center, Greenbelt, MD, United States, (24)Denali Scientific, Fairrbanks, AK, United States, (25)University of California, Los Angeles, CA, United States, (26)Univ New Hampshire, Durham, NH, United States, (27)University of California Los Angeles, Department of Earth, Planetary, and Space Sciences and Institute of Geophysics and Planetary Physics, Los Angeles, CA, United States
Abstract:
Magnetosheath High Speed Jets (HSJs) are regularly observed downstream of the Earth’s bow shock. Determining their origin from spacecraft observations is however a challenge since (1) L1 solar wind monitors are usually used with their inherent inaccuracy when plasma and magnetic data are propagated to the bow shock, (2) the number of measurement points around the bow shock are always limited. Various mechanisms have been proposed to explain HSJs such as bow shock ripples, solar wind discontinuities, foreshock transients, pressure pulses or nano dust clouds and it is difficult to relate these to HSJs with the lack of simultaneous measurements near the bow shock and immediately upstream. We will use a special Cluster campaign, where one spacecraft was lagged 8 hours behind the three other spacecraft, to obtain near-Earth solar wind measurements upstream of the bow shock, together with simultaneous measurements in the magnetosheath. The event of interest is first observed at ACE as a short 10 min. period of IMF-Bx dominant (cone angle around 140 deg.). This IMF-Bx dominant period is also observed, one hour later, by THEMIS B and C (ARTEMIS) and Geotail, which were at 60 and 25 RE from Earth on the dawnside. Cluster 1 just upstream of the bow shock, at 17 RE from Earth, observed also such IMF-Bx dominant period together with energetic ions reflected from the bow shock, variable solar wind beam, foreshock bubbles and hot flow anomalies. Finally, Cluster 3 and 4 and MMS1-4, a few RE from each other downstream of the shock, observed a turbulent magnetosheath with HSJs for 15 minutes. The HSJ characteristics will be investigated with the constellation of 6 spacecraft, as well as their relation with foreshock transients.
