Analysis of Venusian Zonal Winds Using Venus Express Data
We measure the zonal mean wind structure of Venus between 2006 and 2013 in the ultraviolet images captured by the Venus Monitoring Camera (VMC) onboard the ESA Venus Express (VEx) spacecraft which observed Venus’s southern hemisphere. Our wind measurements employ a digital two-dimensional Correlation Imaging Velocimetry (CIV) method to track cloud motions. Our current focus is on understanding the short- and long-term dynamics of Venus’s atmospheric superrotation, in which the equatorial atmosphere rotates with a period of approximately 4-5 days (~60 times faster than the solid planet). The Venusian atmospheric superrotation’s forcing and maintenance mechanisms remain to be explained. A number of studies have been published on the cloud-tracking wind measurements on Venus, however, those different measurements have not reached a consensus on the temporal evolution of the zonal wind structure (e.g., Kouyama et al. (2013), Khatuntsev et al. (2013), Patsaeva et al. (2015)). Temporal evolution of the zonal wind could reveal the transport of energy and momentum and eventually shed a light on mechanisms that maintain the superrotation. Our first goal is to characterize the temporal dynamics of Venus’s zonal wind profile and two-dimensional wind field, in which we will search for equatorial waves (in particular the so-called “Y-feature”) that may force the Venusian atmospheric superrotation.