Adrian LaMoury

Magnetosheath jets are localised high-dynamic pressure pulses originating at Earth’s bow shock and propagating earthward through the magnetosheath. Jets can influence magnetospheric dynamics upon interacting with the magnetopause; however a significant fraction dissipate before reaching it. Using a database of 13,096 jets observed by the THEMIS spacecraft and associated upstream solar wind conditions from OMNI from 2008 to 2018, we statistically determine how upstream solar wind conditions control the likelihood of jets forming at the bow shock, and how they affect the jets’ likelihood of propagating to the magnetopause. We see that these two effects are separate, but when combined, the observations indicate that jets are approximately 12 times more likely to reach and impact the magnetopause during low IMF cone angle conditions, and 5 times more likely during high solar wind speeds. On the other hand, solar wind plasma beta and dynamic pressure display no net effect on magnetopause impacts. Our results suggest that jet impact rates may have a solar cycle dependence as well as vary during the passage of solar wind transients. In addition, we study the properties of near-magnetopause jets to further investigate their potential influence on magnetospheric processes.