2:45 PM - 3:00 PM
[PCG25-15] Investigation of variation mechanisms of the Jovian radiation belt using ALMA
Keywords:Jupiter, ALMA, stratosphere, radiation belt
It is theoretically expected that the driving mechanism of Jovian radiation belt is due to the interaction between the radiation belt and the upper atmospheric dynamics: neutral wind perturbations and diurnal wind system control the radial diffusion and spatial distribution of the energetic particles, respectively. Therefore, precise measurements of Jovian wind field are essential for not only the dynamics of the stratosphere but also the magnetosphere.
ALMA's unprecedented high spatial-spectral resolution enables us to extract the limb emission of the trace gasses in the Jovian upper stratosphere with a few tens m/s sensitivity. It is well known that HCN and CS have been injected into Jupiter by the Shoemaker-Levy 9 impact and they distribute only in the upper atmosphere (p ~0.4-1mbar). Therefore, the Doppler shift of those molecular emission lines can be used to investigate the dynamics in the upper atmosphere particularly at the limb of the Jovian disk where the line-of-sight direction is equal to the horizontal direction of the atmosphere. Here we present the sensitivity of ALMA observation to measuring Jovian stratospheric winds, and discuss its capability of constraining the magnetosphere-atmosphere coupling. A test analysis is carried out using JVO ALMA archive data.