Magnetosheath jets constitute a significant coupling effect between the solar wind (SW) and the magnetosphere of the Earth. In order to investigate the effects and forecasting of these jets, we present the first-ever statistical study of the jet production during large-scale SW structures like coronal mass ejections (CMEs), stream interaction regions (SIRs) and high speed streams (HSSs). Magnetosheath data from Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft between January 2008 to December 2020 serve as measurement source for jet detection. Two different jet definitions were used to rule out statistical biases induced by our jet detection method. For the CME and SIR+HSS lists, we used lists provided by literature and expanded on incomplete lists using OMNI data to cover the time range of May 1996 to December 2020. We find that the number and total time of observed jets decrease when CME-sheaths hit the Earth. The number of jets is lower throughout the passing of the CME-magnetic ejecta (ME) and recovers quickly afterwards. On the other hand, the number of jets increases during SIR and HSS phases. We discuss a few possibilities to explain these statistical results.

Magnetosheath jets are dynamic pressure enhancements observed in the terrestrial magnetosheath. Their generation mechanisms are currently debated but can be linked to foreshock processes. Recent results showed that jets are less numerous when coronal mass ejections (CME) cross the magnetosheath. Here, we show for the first time how CMEs and their magnetic ejecta (ME) region are related to jet production. Based on THEMIS and OMNI data covering 2008–2021, we show the probability distribution of jet production in 2D parameter histograms using the IMF cone angle and Alfvén Mach number. We compare this distribution with the values within CME-MEs. We find high cone angles and low Alfvén Mach numbers within CME-MEs, which both are unfavorable for jet production as they may inhibit a proper foreshock region. We predict that future missions, measuring the magnetosheath of Mercury, will find low numbers of jets due to low Alfvén Mach numbers.