Venus Atmospheric Dynamics at Two Altitudes: Akatsuki and Venus Express Cloud Tracking, Ground-Based Doppler Observations and Comparison with Modelling

We present new results of our studies zonal and meridional winds in both hemispheres Venus, using ground- space-based coordinated observations. The obtained from telescope observations were retrieved with a Doppler velocimetry method. wind velocities space used an improved cloud-tracked technique based on the phase correlation between images. evidence that altitude level sensed by method is approximately four kilometres higher (~4 km) than ground-tracked (using 380 or 365 nm). Since we often take advantage ground simultaneously, this difference will be very relevant order to estimate vertical shear at related heights future observation campaigns. also explored previous campaign Akatsuki its Ultraviolet Imager (UVI) 283 nm filters, which showed about 10–15 ms−1, as case comparison cloudtracked winds. results’ strongly suggested filter’s images sensing same atmospheric observational compared ground-to-thermosphere 3D model developed Laboratoire de Meteorologie Dynamique (IPSL-Venus General Circulation Model (VGCM)) AFES-Venus (GCM), several pressure levels (and heights). analysis following: (1) additional confirmation coherence complementarity provided these techniques spatial temporal time scales two methods; (2) noticed following different Akatsuki/UVI filters (283 nm) average ± 5 suggest may SO2 fluctuations particular conditions observing window; (3) indicating that, context observations, visible methods (highly self-consistent) seem sense speeds closer within range UVI filter (again, observations); (4) modelling predicted profiles suggests layers atmosphere Venus referred Point 3 differ km 2 regarding