• DOI:10.1038/ngeo1650
• Corpus ID: 59323909

Variations of sulphur dioxide at the cloud top of Venus’s dynamic atmosphere

@article{Marcq2012VariationsOS,
  title={Variations of sulphur dioxide at the cloud top of Venus’s dynamic atmosphere},
  author={Emmanuel Marcq and J L Bertaux and Franck Montmessin and Denis Belyaev},
  journal={Nature Geoscience},
  year={2012},
  volume={6},
  pages={25 - 28}
}

• E. Marcq, J. Bertaux, +1 author D. Belyaev
• Published 2 December 2012
• Environmental Science, Physics
• Nature Geoscience

A pulse of sulphur dioxide in Venus’s upper atmosphere was observed by the Pioneer Venus spacecraft in the 1970s and 1980s and attributed to volcanism. Recent sulphur dioxide measurements from Venus Express indicate decadal-scale fluctuations in sulphur dioxide above Venus’s cloud tops in an atmosphere that is more dynamic than expected. Sulphur dioxide is a million times more abundant in the atmosphere of Venus than that of Earth, possibly as a result of volcanism on Venus within the past billion years1,2. A tenfold decrease in sulphur dioxide column density above Venus’s clouds measured by the Pioneer Venus spacecraft during the 1970s and 1980s has been interpreted as decline following an episode of volcanogenic upwelling from the lower atmosphere3,4. Here we report that the sulphur dioxide column density above Venus’s clouds decreased by an order of magnitude between 2007 and 2012 using ultraviolet spectrometer data from the SPICAV instrument onboard the Venus Express spacecraft. This decline is similar to observations during the 1980s. We also report strong latitudinal and temporal variability in sulphur dioxide column density that is consistent with supply fluctuations from the lower atmosphere. We suggest that episodic sulphur dioxide injections to the cloud tops may be caused either by periods of increased buoyancy of volcanic plumes, or, in the absence of active volcanism, by long-period oscillations of the general atmospheric circulation. The 30-year observational record from Pioneer Venus and Venus Express confirms that episodic injections of sulphur dioxide above the clouds recur on decadal timescales, suggesting a more variable atmosphere than expected.