14:15 〜 14:30
[PEM15-09] A study of ion upflow from the polar cap ionosphere
A significant amount of magnetospheric plasma originates from the ionosphere and has been transported to the magnetosphere through the ion outflow process. Cold ions in the magnetosphere predominantly stem from the polar cap ionosphere, where an ambipolar electric field, driven by pressure gradients, initiates the upward flow of ions. Despite its crucial role in the ion upflow/outflow process, several characteristics of the ambipolar electric field, including its magnitude and variability, remains poorly understood.
This study utilizes data from the European Incoherent SCATter (EISCAT) Svalbard radar to investigate some of these characteristics. The EISCAT Svalbard radar started its operations in 1996, and thus the data set is now spanning over two solar cycles. From this extensive data set we will present several identified ion upflow events. For each event, we calculate the ambipolar electric field and examine the associated solar and geomagnetic conditions. A comparison of different events will be presented and discussed.
This study utilizes data from the European Incoherent SCATter (EISCAT) Svalbard radar to investigate some of these characteristics. The EISCAT Svalbard radar started its operations in 1996, and thus the data set is now spanning over two solar cycles. From this extensive data set we will present several identified ion upflow events. For each event, we calculate the ambipolar electric field and examine the associated solar and geomagnetic conditions. A comparison of different events will be presented and discussed.