Date Thesis Awarded
Honors Thesis -- Open Access
Bachelors of Science (BS)
The equatorial atmosphere of Venus rotates 60 times faster than the solid planet, a poorly understood phenomenon known as superrotation. Kelvin-like waves have been hypothesized to maintain the superrotation against dissipation, and the planet- scale “Y-feature”, a transient cloud feature, is likely their visible manifestation. In order to detect these waves, the spatial and temporal evolution of Venus’ atmosphere as a whole must be better characterized on long time scales. Using data from the Venus Monitoring Camera on board Venus Express, we have found yearly average zonal wind profiles by using Correlation Image Velocimetry. In order to better char- acterize the measurement uncertainty and separate it from real variation compared to using the standard deviation, we have developed a method of uncertainty calcula- tion using correlation fields. We observed a consistent trend of increasing zonal wind velocity, about 20 ms−1 over eight years of observation, in the area that the Y-feature is present, which may be caused by Kelvin-like waves accelerating the mean flow. This variation is comparable to the standard deviation and uncertainty, and thus cannot be definitively confirmed. Our new method of uncertainty calculation gave comparable uncertainty to the standard deviation and future work will be needed for improvement in the uncertainty calculation.
Gunnarson, Jacob L., "Characterization of Venusian atmospheric dynamics using Venus Express images and ground-based observations" (2017). Undergraduate Honors Theses. William & Mary. Paper 1023.