High‐Resolution Poynting Flux Statistics From the Swarm Mission: How Much Is Being Underestimated at Larger Scales?

Abstract

The energy transfer rate between the magnetosphere and the ionosphere-thermosphere via field-aligned currents, known as the Poynting flux, quantifies the impact of space weather changes on the atmosphere of Earth. The magnetosphere-ionosphere-thermosphere (MIT) system at high-latitudes is strongly coupled, resulting in Poynting flux transfer significantly affecting many atmospheric features (such as field-aligned currents and neutral density perturbations). In addition to the energy flux from precipitating particles (Newell et al., 2009), it is perhaps one of the most significant measures of the MIT energy budget and thus important to quantify accurately.The Poynting flux along a field line can be considered as consisting of two components. First, the quasi-static/DC large-scale Poynting flux associated with the typical R1/R2 field-aligned current system (Iijima & Potemra, 1976), with a scale size of several hundreds of kilometers at ionospheric F-region altitudes. The second is Poynting flux fluctuations on small spatial scales, less than 10 km, which can include and can be dominated by Alfvénic/AC fluctuations of the electric field (Knudsen et al., 1992). Electric field variability on small spatial and temporal

DMSP Poynting Flux: Data Processing and Inter‐Spacecraft Comparisons

“…They also showed that, consistent with previous reports by Pakhotin et al (2021) for Alfvénic PF, there is a clear preference for excess northern hemisphere deposition of PF. Billett et al (2022) and Cosgrove et al (2022) recently confirmed the northern hemispheric PF preference in re-processed Fast Auroral Snapshot data and Swarm data, respectively. The present paper provides more detail about the processing and inter-comparison of spacecraft data that support the multiyear analysis in Knipp et al (2021) and will support future research.…”

“…Billett et al. (2022) and Cosgrove et al. (2022) recently confirmed the northern hemispheric PF preference in re‐processed Fast Auroral Snapshot data and Swarm data, respectively.…”

Light ion dynamics in the topside ionosphere and plasmasphere during geomagnetic storms

“…In turn, understanding the plasma composition and its dynamics allows to construct more accurate maps of species density profiles, estimate characteristic timescales for significant events, and potentially infer more accurately the degree of electromagnetic coupling between the subsystems. Besides the so-called transition height (i.e., the altitude where [O+] = [H+]), the balance of light and heavy (primarily O+) ions determines the Alfven speed which is an important parameter in MIT coupling through its relationship with integrated Pedersen conductance to form the reflection coefficient governing downwards Poynting flux (Lysak 1991;Knudsen et al 1992;Pakhotin et al 2018Pakhotin et al , 2020Pakhotin et al , 2021Billett et al 2022). In addition, the propagation of magnetospheric plasma waves such as electromagnetic ion cyclotron (EMIC) waves, which play a significant role in radiation belt dynamics (e.g., Shprits et al 2008), is governed by the relative abundances of ion species.…”

Light Ion Dynamics in the Topside Ionosphere and Plasmasphere during Geomagnetic Storms

“…[O+]=[H+]), the balance of light (primarily H+) and heavy (primarily O+) ions determines the Alfven speed which is an important parameter in MIT coupling through its relationship with integrated Pedersen conductance to form the re ection coe cient governing downwards Poynting ux (Lysak, 1991, Knudsen et al, 1992, Pakhotin et al, 2018, 2021, Billett et al, 2022. In addition, the propagation of magnetospheric plasma waves such as electromagnetic ion cyclotron (EMIC) waves, which play a signi cant role in radiation belt dynamics (e.g.…”