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Study of Venus’ Atmospheric Dynamics using Doppler Velocimetry Techniques and VLT/UVES Data
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Resumo(s)
In this thesis the goal is to measure the winds of Venus’s fast rotating atmosphere through the Doppler Velocimetry technique using the high resolution spectrograph UVES on the VLT. Despite being the closest planet to Earth, the scientific community still do not fully understand how did Venus acquire the characteristics it has today, namely its atmospheric dynamics. Venus is a slow rotating planet with a fast rotating atmosphere, this contrast is not yet well explained, we still do not know how the fast rotation was established and how it is maintained over time. Measuring and monitoring the velocity of the winds in the rotating atmospehre will help us progress towards answers. We will repeat the same set of procedures from previous studies (Pedro Machado et al. (2012); Pedro Machado (2014)) but using a new set of more recent data from the UVES. The high spectral resolution from UVES and its wide spectral range will allow us to measure in detail the Doppler shift from every Fraunhofer line that is reflected by the fast moving particles in the upper layer of Venus’s clouds. The observations use a long slit that is placed perpendicularly to the rotation axis in specific latitude circles, since the zonal wind is practically independent from longitude, with the exception of local oscillations, each observation will have a nearly constant wind velocity. In this thesis we will only display the results from one exposure, however, in further work, a latitudinal profile will be assembled using all exposures from all slit positions, and local oscillation patterns will be studied. This method is the only way we can measure in detail and with accuracy the velocity winds of Venus’s zonal rotation since corrently there is no space probes orbiting Venus and the only way we can observe it is from ground. We successfully managed to obtained and measured the absolute velocity values of atmospheric winds, which were consistent with results from previous studies, concluding that the Doppler velocimetry tecnique is an effective method for studying atmospheric dynamics.
Descrição
Tese de mestrado, Física e Astrofísica, 2026, Universidade de Lisboa, Faculdade de Ciências
Palavras-chave
Venus Doppler velocimetry Retrograde zonal superrotation High resolution spectroscopy Zonal winds