Inter‐Hemispheric Energy Input Into the Ionosphere‐Thermosphere System During Magnetic Storms: What We Can and Cannot Learn From DMSP Observations

• Published in: Journal of geophysical research. Space physics 2024-05, Vol.129 (5), p.n/a
• Main Authors: Oliveira, Denny M., Zesta, Eftyhia
• Format: Article
• Language: English
• Subjects: Coronal mass ejection; DMSP satellites; Energy; Energy flux; Fluctuations; Geomagnetic storms; Interplanetary magnetic field; inter‐hemispheric asymmetries; Ion precipitation; Ionosphere; Magnetic fields; Magnetic storms; Magnetospheres; magnetosphere‐ionosphere coupling; Meteorological satellite program; Meteorological satellites; Northern Hemisphere; Plasma drift; Satellite observation; Southern Hemisphere; Storms; Thermosphere
• ISSN: 2169-9380; 2169-9402
• DOI: 10.1029/2024JA032486

We present a long‐term superposed epoch analysis and statistical study with 427 magnetic storms caused by coronal mass ejections and the subsequent magnetospheric energy input into the ionosphere‐thermosphere system. Electron and ion precipitating energy flux data along with plasma drift velocity and magnetic field data (used for Earth‐bound Poynting flux computations) are used in this study. By carefully exploring conjugated inter‐hemispheric energy inputs as a function of storm intensity and seasons, we find that near two‐decades of Defense Meteorological Satellite Program observations indicate that the northern hemisphere (NH) receives slightly more energy than the southern hemisphere (SH) (Poynting flux and integrated electron/ion precipitating energy flux), with the NH receiving more energy as the storm becomes more intense. However, for the Poynting flux case, we find that generally the SH receives more energy when the east‐west component of the interplanetary magnetic field (IMF) becomes highly positive (By ≥ +5 nT), whereas this pattern reverses for cases when IMF By is highly negative (By ≤ −5 nT). The inter‐hemispheric interpretation for electron and ion precipitation energy inputs is ambiguous due to a severe lack of conjugated observations around the midnight sector for both hemispheres. Key Points The northern hemisphere (NH) appears to receive slightly more electromagnetic and particle precipitation energies in comparison to the southern hemisphere (SH) All types of energy inputs are higher on the dawnside in comparison to the duskside for all storm intensities and seasons in the NH and SH Defense Meteorological Satellite Program cannot provide conclusive answers to the problem of storm‐time IH asymmetries in the ionosphere‐thermosphere system due to incomplete conjugated orbits