Heli Hietala
Assistant Researcher
6844 Geology


Heli Hietala studies particle energization in shocks, magnetic reconnection, and radiation belts using multi-spacecraft observations and modelling.

She is currently an Assistant Researcher in the Experimental Space Physics Group, Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles.


Lead-proposer and co-chair of the GEM Focus Group "Dayside kinetic processes in global solar wind - magnetosphere interaction" (2016-2020).

Co-leader of the International Space Science Institute (ISSI) International Team Jets Downstream of Collisionless Shocks (2015-2017), and the co-I of the global hybrid-Vlasov simulation model Vlasiator.

Young Scientist in the ISSI team Ion and Electron Bulk Heating by Magnetic Reconnection (2013-2015).

Visit my Orcid Page


Selected Publications

Mistry, R., J.P. Eastwood, C.C. Haggerty, M.A. Shay, T.D. Phan, H. Hietala, and P.A. Cassak, Observations of Hall Reconnection Physics Far Downstream of the X Line, Phys. Rev. Lett. 117, 185102, doi:10.1103/PhysRevLett.117.185102.

Pfau-Kempf, Y., Hietala, H., Milan, S. E., Juusola, L., Hoilijoki, S., Ganse, U., von Alfthan, S., and Palmroth, M.: Evidence for transient, local ion foreshocks caused by dayside magnetopause reconnection, Ann. Geophys., 34, 943-959, doi:10.5194/angeo-34-943-2016, 2016.

Turner, D. L., T. P. O'Brien, J. F. Fennell, S. G. Claudepierre, J. B. Blake, E. K. J. Kilpua, and H. Hietala (2015), The effects of geomagnetic storms on electrons in Earth's radiation belts, Geophys. Res. Lett., 42, 9176–9184, doi:10.1002/2015GL064747.

Eriksson E., A. Vaivads, D. B. Graham, Yu. V. Khotyaintsev, E. Yordanova, H. Hietala, M. André, L. A. Avanov, J. C. Dorelli, D. J. Gershman, B. L. Giles, B. Lavraud, W. R. Paterson, C. J. Pollock, Y. Saito, W. Magnes, C. Russell, R. Torbert, R. Ergun, P-A. Lindqvist, J. Burch (2016), Strong current sheet at a magnetosheath jet: kinetic structure and electron acceleration, J. Geophys. Res., 121, doi:10.1002/2016JA023146.

Liu, T. Z., H. Hietala, V. Angelopoulos, and D.L. Turner (2016), Observations of a new foreshock region upstream of a foreshock bubble's shock, Geophys. Res. Lett., DOI: 10.1002/2016GL068984.

Plaschke, F., H. Hietala, V. Angelopoulos, and R. Nakamura (2016), Geoeffective jets impacting the magnetopause are very common, J. Geophys. Res. Space Physics, 121, doi:10.1002/2016JA022534.

Eastwood, J. P., M. V. Goldman, H. Hietala, D. L. Newman, R. Mistry, and G. Lapenta (2015), Ion reflection and acceleration near magnetotail dipolarization fronts associated with magnetic reconnection, J. Geophys. Res. Space Physics, 120, 511–525, doi:10.1002/2014JA020516.

Eastwood, J.P., H. Hietala, G. Toth, T.D. Phan, M. Fujimoto, What Controls the Structure and Dynamics of Earth’s Magnetosphere?, Space Sci. Rev., 188: 251. doi:10.1007/s11214-014-0050-x.

Palmroth, M., et al. (2015), ULF foreshock under radial IMF: THEMIS observations and global kinetic simulation Vlasiator results compared, J. Geophys. Res. Space Physics, 120, 8782–8798, doi:10.1002/2015JA021526.

Hietala, H., J. F. Drake, T. D. Phan, J. P. Eastwood, and J. P. McFadden (2015), Ion temperature anisotropy across a magnetotail reconnection jet, Geophys. Res. Lett., 42, 7239–7247, doi:10.1002/2015GL065168.

Kilpua, E. K. J., H. Hietala, D. L. Turner, H. E. J. Koskinen, T. I. Pulkkinen, J. V. Rodriguez, G. D. Reeves, S. G. Claudepierre, and H. E. Spence (2015), Unraveling the drivers of the storm time radiation belt response. Geophys. Res. Lett., 42, 3076–3084. doi: 10.1002/2015GL063542.

Mistry, R., J. P. Eastwood, and H. Hietala (2015), Detection of small-scale folds at a solar wind reconnection exhaust, J. Geophys. Res. Space Physics, 120, 30–42, doi:10.1002/2014JA020465.

Mistry, R., J. P. Eastwood, T. D. Phan, and H. Hietala (2015), Development of bifurcated current sheets in solar wind reconnection exhausts, Geophys. Res. Lett., 42, 10,513–10,520, doi:10.1002/2015GL066820.