SHARP (SHocks: structure, AcceleRation, dissiPation)

The SHARP project is funded by the European Union’s Horizon 2020 research and innovation programme. Running 3 years from January 1st, 2021 Swedish Institute of Space Physics (IRF) collaborates with world-leading experts on collisionless shocks with the goal to achieve a breakthrough in our understanding of collisionless shocks across multiple plasma environments.

IRF leads a work package to develop an extensive database of collisionless shock crossings by spacecraft on Earth, Mars, Venus, and interplanetary space. This assists future shock investigations by making it easier to find shock matching specific criteria and/or by providing a means to perform large-scale statistical studies. IRF also contribute to other work packages that will advance scientific understanding of shocks.

Shockwaves appear everywhere in space, around planets, comets, the interplanetary medium, and interstellar space. They are of exceptionally high scientific interest because they are known to be one of the most efficient accelerators of particles in space. On Earth, shock waves are also common such as those at fast-moving objects. However, these types of shocks differ from shocks in space since plasma shocks are collisionless, meaning collisions between particles are so rare that they can be ignored entirely. Instead, the interaction between the particles and electric and magnetic fields governs shock physics. For this reason, space is an ideal laboratory to study collisionless shocks. The only type of shocks that can be reached by spacecraft is those in our solar system. On the other hand, distant astrophysical shocks can only be studied remotely based on the types of radiation they emit.

Latest Activities

Publication by Andreas Johlander (link to paper) on electron heating scales in collisionless shocks
IRF held a collisionless shock meeting (schedule available here) that was hybrid with over 35 participants
Publication by A. P. Dimmock (link to paper) on back streaming ions at a high Mach number interplanetary shock
Publication by D. B. Graham (link to paper) submitted to JGR: space physics on ion dynamics across a low Mach number bow shock
IRF SHARP team (A. P. Dimmock, D. B. Graham, and A. Lalti) gave lectures and workshops at the SHARP summer school in Levi, Finland.

Shock databases

A machine learning method was applied to observations of the Magnetospheric Multiscale (MMS) spacecraft (Olshevsky et al., 2021) to automatically identify bow shock traversals. A database of 2,797 shock crossings from October 2015 to December 2020 (including various spacecraft-related and shock-related parameters) was created as well as quick-look plots for each shock. The terrestrial shock database is available through the SHARP webpage or Zenodo and fully documented in Lalti et al., 2022.

How to access the database(s):

Note that databases on interplanetary shocks (ARTEMIS), Venus (Venus Express), and Mars (MAVEN) are available via the SHARP website.

References:

Olshevsky, V., Khotyaintsev, Y. V., Lalti, A., Divin, A., Delzanno, G. L., Anderzén, S., et al. (2021). Automated classification of plasma regions using 3D particle energy distributions. Journal of Geophysical Research: Space Physics, 126, e2021JA029620. https://doi.org/10.1029/2021JA029620

Lalti, A., Khotyaintsev, Yu. V., Dimmock, A. P., Johlander, A., Graham, D. B., & Olshevsky, V. (2022). A database of MMS bow shock crossings compiled using machine learning. Journal of Geophysical Research: Space Physics, 127, e2022JA030454. https://doi.org/10.1029/2022JA030454

Johlander, A., Khotyaintsev, Y. V., Dimmock, A. P., Graham, D. B., & Lalti, A. (2023). Electron heating scales in collisionless shocks measured by MMS. Geophysical Research Letters, 50, e2022GL100400. https://doi.org/10.1029/2022GL100400

A. P. Dimmock, M. Gedalin, A. Lalti, D. Trotta, Yu. V. Khotyaintsev, D. B. Graham, A. Johlander, R. Vainio, X. Blanco-Cano, P. Kajdič, C. J. Owen and R. F. Wimmer-Schweingruber, Backstreming ions at a high Mach number interplanetary shock: Solar Orbiter measurements during the nominal mission phase, Astronomy & Astrophysics, https://doi.org/10.1051/0004-6361/202347006

D. B. Graham, Yu. V. Khotyaintsev, A. P. Dimmock, A. Lalti, J. J. Boldu, S. F. Tigik, S. A. Fuselier, Ion Dynamics across a Low Mach Number Bow shock, submitted to JGR: Space Physics, https://arxiv.org/abs/2311.11373

Acknowledgment

These works are supported by the European Union’s Horizon 2020 research and innovation program under grant agreement number 101004131 (SHARP).