Authors: Zubair Shaikh (Space Sciences Laboratory, University of California at Berkeley, CA, USA,), Ivan Vasko (William B. Hanson Center for Space Sciences, University of Texas at Dallas, Richardson, TX, USA)

Electrostatic solitary waves (ESWs) are localized, non-linear structures commonly observed in various space plasma environments, including the Earth’s magnetosphere, solar wind, and planetary magnetospheres. It plays a critical role in transferring energy and momentum in plasmas, influencing processes such as particle acceleration, turbulence, and plasma heating. We present a statistical analysis of >2100 bipolar solitary waves observed within three distinct Earth’s Magnetosheath observed by the Magnetospheric Multiscale (MMS) Mission. We argue that ~48% of observed ESWs show positive polarity, whereas 52% have negative polarity. The observed positive and negative potential structures are well separated, and both the waves have almost similar properties, such as a length of few Debye-scale, with velocities <200 km/s and amplitudes between 0.01% and 10% of local electron temperature. We further demonstrated that the observed positive polarity ESWs are electron holes (EHs), whereas the negative polarity is ion holes (IHs).  We also present evidence that observed ESWs are slow EHs and slow-IHs; their plasma frame velocities are significantly lower than electron thermal speed and comparable with ion thermal speed. Both of them have quasi-Maxwellian ion velocity distribution functions. Interestingly, we noted that the effect of turbulence on the nature and characteristics of EHs/IHs is negligible. Our detailed analysis enhances the understanding of the high-frequency electrostatic fluctuations within the turbulent plasma regimes, which can be useful for exploring the fundamental electrostatic plasma processes in the planetary magnetosphere and interplanetary space.