IMF By Effects on the Strength and Latitude of Polar Electrojets: CHAMP and Swarm Joint Observations

Abstract

AbstractIn this study, the impact of the interplanetary magnetic field (IMF) By component on the peak strength and position of polar electrojets (PEJs) is analyzed, based on 16 years of joint observations from Challenging Minisatellite Payload (CHAMP; 2000–2010) and Swarm (2014–2020) satellites, while focusing on the local time and hemispherical differences. With a more positive IMF By, the duskside eastward PEJ enhances significantly at June solstice in the Northern Hemisphere. Around midnight, the impact of IMF By on the PEJ is more significant in the winter hemisphere; the westward PEJ is stronger in the Northern (Southern) Hemisphere for a more positive (negative) IMF By. In 03–08 MLT, the impact of IMF By is similar in both the winter and summer hemispheres: for IMF By > 0 and By < 0, the PEJ in the dawn sector is stronger in the December and June solstices, respectively. Around noon, a more duskward (dawnward) IMF By component leads to a higher eastward (westward) PEJ in the northern (southern) summer hemisphere. The northern westward (eastward) PEJ peaks at higher latitudes than the southern PEJ for a negative (positive) IMF By.