Ammonia and Eddy Mixing Variations in the Upper Troposphere of Jupiter from HST Faint Object Spectrograph Observations

Photochemistry and diffusion in Jupiter's stratosphere: Constraints from ISO observations and comparisons with other giant planets

“…From ground‐based thermal‐infrared observations of NH 3 , Lara et al [1998] conclude that K ranges from ≲400 to ∼4000 cm 2 s −1 at 240 mbar, with the exact value depending on latitude. By comparing ultraviolet Hubble Space Telescope (HST) Faint Object Spectrograph (FOS) observations with the PH 3 and NH 3 distributions from photochemical models, Edgington et al [1998, 1999] also find that K varies with latitude, with derived values of K min ranging from ∼200 to 600 cm 2 s −1 at 80–1000 mbar. One advantage of these techniques is that observational inferences of the altitude distribution of NH 3 and PH 3 can provide information about the altitude variation of K .…”

“…The individual data points represent constraints reported from various observations, as labeled. The error bars in the case of the Lara et al [1998] and Edgington et al [1999] points indicate the range of derived values at different latitudes rather than true error bars. The pressure levels for the reported values of K h were estimated through information given in the published reports and/or through personal communications (e.g., P. Drossart, 1999, and G. R. Gladstone, 2002 to J. I. Moses) and are approximate.…”

Carbon Monoxide on Jupiter: Evidence for Both Internal and External Sources

“…From the NH 3 scale height in the upper troposphere as inferred from 10-µm observations, Lara et al (1998) suggest an eddy mixing coefficient at 240 mbar varying with latitude from ∼4000 to ≤ 400 cm 2 s −1 . Analyzing the distribution of NH 3 from HST/FOS spectra and using a photochemical model, Edgington et al (1999) also find a large horizontal variation of K at 250 mbar, from <1 × 10 3 to 1 × 10 4 cm 2 s −1 . Their eddy mixing profiles reach a minimum K 0 = 300-600 cm 2 s −1 at a pressure level between 100 and 300 mbar.…”

Upper limits on hydrogen halides in Jupiter from Cassini/CIRS observations

“…In this case, Bézard et al (2002) showed that the atmospheric column density a of a given species is equal to a = 2P H 2 /K 0 , where P is the external flux, and H the atmospheric scale height. For K 0 , we followed the work of Edgington et al (1999), which yielded K 0 = 500 cm −2 s −1 for the tropopause level at 18 • N. This gives upper limits on the flux of 1.6 × 10 5 , 1.3 × 10 7 , 5.9 × 10 6 , and 4.6 × 10 7 cm −2 s −1 for F, Cl, Br, and I atoms, respectively.…”