EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

The solar wind angular-momentum flux observed during Solar Orbiter's first orbit

Daniel Verscharen1,2, David Stansby1, Adam Finley3, Christopher Owen1, Timothy Horbury4, Marco Velli5, Stuart Bale4,6,7, Philippe Louarn8, Andrei Fedorov8, Roberto Bruno9, Stefano Livi10, Gethyn Lewis1, Chandrasekhar Anekallu1, Christopher Kelly1, Gillian Watson1, Dhiren Kataria1, Helen O'Brien4, Vincent Evans4, and Virginia Angelini4
Daniel Verscharen et al.
  • 1Mullard Space Science Laboratory, University College London, Dorking, United Kingdom (
  • 2Space Science Center, University of New Hampshire, Durham NH, United States
  • 3DRF/IRFU/DAp/LDE3, CEA Paris-Saclay, Gif-sur-Yvette, France
  • 4Department of Physics, The Blackett Laboratory, Imperial College London, London, United Kingdom
  • 5Department of Earth, Planetary, and Space Sciences, University of California Los Angeles, Los Angeles CA , United States
  • 6Space Sciences Laboratory and Physics Department, University of California, Berkeley CA, United States
  • 7School of Physics and Astronomy, Queen Mary University of London, London, United Kingdom
  • 8Institut de Recherche en Astrophysique et Planétologie, Toulouse, France
  • 9INAF-Istituto di Astrofisica e Planetologia Spaziali, Roma, Italy
  • 10Southwest Research Institute, San Antonio TX, United States

The Solar Orbiter mission is currently in its cruise phase, during which the spacecraft's in-situ instrumentation measures the solar wind and the electromagnetic fields at different heliocentric distances. 

We evaluate the solar wind angular-momentum flux by combining proton data from the Solar Wind Analyser (SWA) Proton-Alpha Sensor (PAS) and magnetic-field data from the Magnetometer (MAG) instruments on board Solar Orbiter during its first orbit. This allows us to evaluate the angular momentum in the protons in addition to that stored in magnetic-field stresses, and compare these to previous observations from other spacecraft. We discuss the statistical properties of the angular-momentum flux and its dependence on solar-wind properties. 

Our results largely agree with previous measurements of the solar wind’s angular-momentum flux in the inner heliosphere and demonstrate the potential for future detailed studies of large-scale properties of the solar wind with the data from Solar Orbiter.

How to cite: Verscharen, D., Stansby, D., Finley, A., Owen, C., Horbury, T., Velli, M., Bale, S., Louarn, P., Fedorov, A., Bruno, R., Livi, S., Lewis, G., Anekallu, C., Kelly, C., Watson, G., Kataria, D., O'Brien, H., Evans, V., and Angelini, V.: The solar wind angular-momentum flux observed during Solar Orbiter's first orbit, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6306,, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.