Details

Autor(en) / Beteiligte

• Peralta, J.
• Hueso, R.
• Sánchez-Lavega, A.
• Piccioni, G.
• Lanciano, O.
• Drossart, P.

Titel

Characterization of mesoscale gravity waves in the upper and lower clouds of Venus from VEX-VIRTIS images

Ist Teil von

• Journal of Geophysical Research - Planets, 2008-05, Vol.113 (E5), p.E00B18-n/a

Ort / Verlag

American Geophysical Union

Erscheinungsjahr

2008

Link zum Volltext

Quelle

Wiley Online Library All Journals

Beschreibungen/Notizen

• Images obtained from the Visible and InfraRed Thermal Imaging Spectrometer (VIRTIS)‐M instrument onboard Venus Express present visible trains of alternating bands of cloud brightness in two different layers: at the upper cloud tops (∼66 km altitude) observed in the dayside hemisphere using reflected ultraviolet light (380 nm) and in the lower cloud (∼47 km altitude) observed in the nightside hemisphere using thermal radiation (1.74 μm). The waves are nearly zonal (with the bands perpendicular to latitude circles), have wavelengths of 60–150 km, propagate westward with low phase velocities relative to the zonal flow, and are confined in wave packets of 400 to 1800 km in length. The waves in the lower cloud observed in the infrared are widely distributed around the planet, and their appearance varies widely throughout the VIRTIS data set. The locations of both types of waves seem not correlated with latitude, local times, surface topography, or the structure of the wind. In both cases the characteristics of the waves correspond to gravity waves propagating in confined stable layers of the atmosphere. We examine the properties of these waves in terms of a linear model and perform a simple analysis to discuss the vertical stability of the atmosphere within Venus clouds.