(Proposal ID) S14A-061

(PI) Kasaba Yasumasa

(Proposal Title)
 Horizontal and vertical structure of Jovian IR aurora observed with SPRINT-A

(Abstract)
We propose the IRCS observation of Jupiter's aurora emission lines, i.e., the 
spectroscopy of multiple H_2 and H^+_3 lines in K-band with the narrow-band 
imaging of H^+_3 lines in L-band in Feb 2014. IRCS can simultaneously observe 
them and enables us to derive precise column densities and temperatures of 
neutral (H_2) and plasma (H^+_3 ) atmospheres along same line-of-sights from 
flux and intensity ratio of these emission lines. From this high-quality data, 
we investigate the contradicted differences in the horizontal and vertical 
distributions of neutral (H_2) and plasma (H^+_3 ) aurora found in our last 
observation. Comparison of these characters in north and south will also be 
executed. As S11B0073N, this observation includes the utilization of AO188 
locked to a Galilean satellite, which can provides high spatial resolution 
( 0.1" = 300km at Jupiter) enough for our studies without the improvement by 
emission model fittings. This proposal is the first joint observation of IRCS 
with SPRINT-A which provides the continuous information of aurora activity in 
UV and Io plasma torus in EUV in Dec 2013 - Apr 2014. We will investigate 
Jovian thermalization of thermosphere / ionosphere coupled to energetic 
electrons illuminating UV aurora and magnetospheric plasmas procured from Io 
volcanos.