Dawn‐Dusk Asymmetries in Jupiter's Magnetosphere

Local time asymmetries in the structure of a planetary magnetosphere are fundamentally the result of the solar-wind interaction with the magnetosphere. In contrast to the Earth, Jupiter has a rotationally driven magnetosphere with an internal primary plasma source, the moon Io. Nevertheless, local time, particularly dawn-dusk, asymmetries are observed throughout the Jovian magnetosphere. For instance, the configuration of the magnetic field, the plasma flows around the planet, the current distribution, and the current sheet thickness all exhibit discrepancies between dawn and dusk. In addition, the auroral emissions in the ionosphere of Jupiter display these dawn-dusk asymmetries in their shape and their brightness. In this chapter, we review the dawn-dusk asymmetries that have been modeled or observed by the different spacecraft having explored the largest magnetosphere of the solar system.