Cloud-tracked winds from Pioneer Venus OCPP images.
Abstract
Analysis of ultraviolet image sequences, obtained from the Pioneer Venus Orbiter Cloud Photopolarimeter and covering five 80-day periods from 1979-1985, provides the first climatological description of the cloud top circulation on Venus. The average zonal winds can be characterized as a 5-day retrograde rotation of the whole cloud-level atmosphere with weak "jets" at middle to high latitudes. Both the midlatitude and equatorial zonal winds vary by about 5-8 m s-1 over time spans of 1-6 years. The average meridional circulation is poleward in both hemispheres up to at least 60° latitude, consistent with the presence of a thermally direct Hadley circulation associated with the clouds. The strength of the Hadley circulation also varies with time. Four wave modes are clearly identified: a diurnal solar tide, a semi-diurnal solar tide, a "4-day equatorial" wave, and a "5-day midlatitude" wave. The properties of the wave modes are discussed in detail.
- Publication:
-
Journal of the Atmospheric Sciences
- Pub Date:
- September 1990
- DOI:
- Bibcode:
- 1990JAtS...47.2053R
- Keywords:
-
- Atmospheric Circulation;
- Clouds (Meteorology);
- Planetary Meteorology;
- Satellite Imagery;
- Venus Atmosphere;
- Wind Profiles;
- Correlation Coefficients;
- Pioneer Venus 1 Spacecraft;
- Polarimetry;
- Ultraviolet Photometry;
- Zonal Flow (Meteorology);
- Venus Atmosphere: UV Images;
- Venus Atmosphere: Circulation;
- Venus Atmosphere: Winds;
- Venus Atmosphere: Clouds