Modeling of Jupiter's auroral curtain and upper atmospheric thermal structure

Abstract

A three-dimensional simulation that takes into account the altitude extent of auroral emission along the line of sight has been applied to the analysis of auroral images of Jupiter taken by the Hubble Space Telescope (HST). The simulation's input auroral emission profile with altitude was expanded by an emission scale height factor ranging from n = 1 to n = 4 representing different vertical extents of the auroral emission (i.e., one to four times greater than the theoretical emission profile from Grodent et al. (2001)). A radial cut of the auroral brightness averaged over an angle of 5 was compared between the original HST images and each of the series' simulation outputs. We found that four of the five northern series showed the original image's emission profile well bounded by the n = 1 and n = 2 simulation outputs, while four of the five southern series showed the original image's auroral emission profile better correlated with the n = 3 simulation. This hemispheric difference could be the result of increased heating or a different distribution of influx electron energies at the southern hemisphere. The discovery of this hemispheric temperature difference supports predictions made by a three-dimensional thermospheric wind model and makes a strong case for further study of the effects of Joule heating on the auroral regions. Copyright 2011 by the American Geophysical Union.