The ionosphere of Jupiter in the Juno era

点击翻译按钮获取中文摘要

"The NASA Juno spacecraft has been in orbit at Jupiter since 2016 in 53 day long polar orbit. This provides completely new and dramatic views of the planet, very different from the ones we get from here at Earth. The near-infrared instrument on the orbiter (JIRAM - the Jovian Infrared Auroral Mapper) provides stunning data of ionosphere, the charged particle component of the upper atmosphere. The ionosphere is a very important region since it can 'feel' the magnetic field, and is there for a region where momentum and energy is exchanged between the atmosphere and the magnetosphere. The stunningly bright and variable auroral displays at Jupiter provides a mechanism to heat the upper atmosphere at the poles, but how is this energy re-distributed towards lower latitudes? Our understanding of the ionosphere away from the auroral region is very limited, and Juno JIRAM provides a window through which we can begin to understand this region. A dominant ion in the ionosphere is the molecular ion H3+, and by fitting its observed spectrum using the model developed at Leicester we can determine the temperature and ion density of any particular point on the planet, with each successive orbit providing a view of how this changes over time. This project will investigate how energy is re-distributed in the upper atmosphere of Jupiter, and how important the heating by gravity waves, generated by the turbulent lower atmosphere, are on a global scale. Will also have the opportunity to lead Juno support observations using the NASA Infrared Telescope Facility in Hawaii, from which we can determine the amount of forcing that the magnetosphere exerts on the ionosphere and atmosphere, a highly complementary data product to the high spatial resolution data taken by Juno JIRAM.