资源环境科技发展态势分析平台

Jupiter's tropospheric ammonia (NH3) abundance is studied using spatially resolved 5 mu m observations from the cryogenic high-resolution infrared spectrograph (CRIRES) at the European Southern Observatory's Very Large Telescope. The high-resolving power (R = 96,000) allows the line shapes of three NH3 absorption features to be resolved. We find that within the 1-4 bar pressure range, the NH3 abundance decreases with altitude. The instrument slit was aligned north-south along Jupiter's central meridian, allowing us to search for latitudinal variability. There is considerable uncertainty in the large-scale latitudinal variability, as the increase in cloud opacity in zones compared to belts can mask absorption features. However, we do find evidence for a strong NH3 enhancement at 4-6 degrees N, consistent with a localized "ammonia plume" on the southern edge of Jupiter's North Equatorial Belt.