TY - JOUR
T1 - First 3D hybrid-Vlasov global simulation of auroral proton precipitation and comparison with satellite observations
AU - Grandin, Maxime
AU - Luttikhuis, Thijs
AU - Battarbee, Markus
AU - Cozzani, Giulia
AU - Zhou, Hongyang
AU - Turc, Lucile
AU - Pfau-Kempf, Yann
AU - George, Harriet Elizabeth
AU - Horaites, Konstantinos
AU - Gordeev, Evgenii
AU - Ganse, Urs
AU - Papadakis, Konstantinos
AU - Alho, Markku Juhani
AU - Kebede, Fasil Tesema
AU - Suni, Jonas Emil
AU - Dubart, Maxime
AU - Tarvus, Vertti Aleksanteri
AU - Palmroth, Minna
PY - 2023/7/10
Y1 - 2023/7/10
N2 - The precipitation of charged particles from the magnetosphere into the ionosphere is one of the crucial coupling mechanisms between these two regions of geospace and is associated with multiple space weather effects, such as global navigation satellite system signal disruption and geomagnetically induced currents at ground level. While precipitating particle fluxes have been measured by numerous spacecraft missions over the past decades, it often remains difficult to obtain global precipitation patterns with a good time resolution during a substorm. Numerical simulations can help to bridge this gap and improve the understanding of mechanisms leading to particle precipitation at high latitudes through the global view they offer on the near-Earth space system. We present the first results on auroral (0.5-50 keV) proton precipitation within a 3-dimensional simulation of the Vlasiator hybrid-Vlasov model. The run is driven by southward interplanetary magnetic field conditions with constant solar wind parameters. We find that on the dayside, cusp proton precipitation exhibits the expected energy-latitude dispersion and takes place in the form of successive bursts associated with the transit of flux transfer events formed through dayside magnetopause reconnection. On the nightside, the precipitation takes place within the expected range of geomagnetic latitudes, and it appears clearly that the precipitating particle injection is taking place within a narrow magnetic local time span, associated with fast Earthward plasma flows in the near-Earth magnetotail. Finally, the simulated precipitating fluxes are compared to observations from Defense Meteorological Satellite Program spacecraft during driving conditions similar to those in the simulation and are found to be in good agreement with the measurements.
AB - The precipitation of charged particles from the magnetosphere into the ionosphere is one of the crucial coupling mechanisms between these two regions of geospace and is associated with multiple space weather effects, such as global navigation satellite system signal disruption and geomagnetically induced currents at ground level. While precipitating particle fluxes have been measured by numerous spacecraft missions over the past decades, it often remains difficult to obtain global precipitation patterns with a good time resolution during a substorm. Numerical simulations can help to bridge this gap and improve the understanding of mechanisms leading to particle precipitation at high latitudes through the global view they offer on the near-Earth space system. We present the first results on auroral (0.5-50 keV) proton precipitation within a 3-dimensional simulation of the Vlasiator hybrid-Vlasov model. The run is driven by southward interplanetary magnetic field conditions with constant solar wind parameters. We find that on the dayside, cusp proton precipitation exhibits the expected energy-latitude dispersion and takes place in the form of successive bursts associated with the transit of flux transfer events formed through dayside magnetopause reconnection. On the nightside, the precipitation takes place within the expected range of geomagnetic latitudes, and it appears clearly that the precipitating particle injection is taking place within a narrow magnetic local time span, associated with fast Earthward plasma flows in the near-Earth magnetotail. Finally, the simulated precipitating fluxes are compared to observations from Defense Meteorological Satellite Program spacecraft during driving conditions similar to those in the simulation and are found to be in good agreement with the measurements.
KW - 114 Physical sciences
KW - Auroral proton precipitation
KW - Model-observation comparison
KW - Numerical simulations
U2 - 10.1051/swsc/2023017
DO - 10.1051/swsc/2023017
M3 - Article
SN - 2115-7251
VL - 13
JO - Journal of space weather and space climate
JF - Journal of space weather and space climate
M1 - 20
ER -