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Self‐consistent evolution of auroral downward‐current region ion outflow and moving double layer
Author(s) -
Hwang K.J.,
Ergun R. E.,
Newman D. L.,
Tao J.B.,
Andersson L.
Publication year - 2009
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2009gl040585
Subject(s) - outflow , ion , population , physics , current (fluid) , atomic physics , meteorology , thermodynamics , demography , quantum mechanics , sociology
Vlasov simulations have been performed to investigate the development and evolution of the parallel potential drop, often structured as a localized double layer (DL), electron phase‐space holes, and ion perpendicular heating, resulting in ion outflow in the auroral downward‐current region. We focus on the feedback between a moving DL and heated ions, suggesting a self‐consistent model: the heated ions regulate the evolution of the DL which controls the level of ion heating and, consequently, the outflow rate. Strongly heated ions forming conics are found in agreement with in‐situ observations. The intensification and widening of the DL develops with time, and the DL eventually weakens due to a reduction in the background population resulting from excessive ion heating.