Ground-based observations were used to map Venus’ three-dimensional thermal structure.
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A temperature offset map from February 2019 shows a planetary-scale wave.
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The wave pattern is consistent with an upward propagating thermal tide.
Abstract
High spectral resolution observations of Venus were obtained with the TEXES instrument at NASA’s Infrared Telescope Facility. These observations focus on a CO2 absorption feature at 791.4 cm-1 as the shape of this absorption feature can be used to retrieve the vertical temperature profile in Venus’ mesosphere. By scan-mapping the planet, we are able to build up three-dimensional temperature maps of Venus’ atmosphere, covering one Earth-facing hemisphere and an altitude range of 60–83 km. A temperature map from February 12, 2019 clearly shows the three-dimensional structure of a planetary-scale thermal wave. This wave pattern appears strongest in the mid-latitudes of Venus, has a zonal wavenumber of 2–4 and the wave fronts tilt eastward with altitude at an angle of 8–15 degrees per km. This is consistent with a thermal tide propagating upwards from Venus’ upper cloud decks. Ground-based observations provide the opportunity to study Venus’ temperature structure on an ongoing basis.
