Venera-15 and -16 middle atmosphere profiles from radio occultations: Polar and near-polar atmosphere of Venus

Solar migrating atmospheric tides in the winds of the polar region of Venus

“…Nevertheless, the persistent nature of the cold collar is still doubtful as it was not seen in some southern hemisphere profiles from Pioneer Venus (Kliore and Patel, 1982) nor was it detected in the three northern hemisphere occultation profiles retrieved from Magellan (Jenkins et al, 1994). Moreover, zonal and meridional decoupling among different harmonics is an expected tidal feature for regions with isothermal conditions (Volland, 1988), which in turn is a characteristic of the polar collar region in both hemispheres as confirmed by most studies (Taylor et al, 1980;Yakovlev et al, 1991;Jenkins et al, 1994;Tellmann et al, 2009). …”

“…This inversion layer was first observed in the northern hemisphere by Pioneer Venus (Taylor et al, 1980;Kliore and Patel, 1982;Newman et al, 1984), and in the southern hemisphere by Venera 15 and 16 (Yakovlev et al, 1991) and, more recently, by Venus Express (Grassi et al, 2008;Tellmann et al, 2009). Nevertheless, the persistent nature of the cold collar is still doubtful as it was not seen in some southern hemisphere profiles from Pioneer Venus (Kliore and Patel, 1982) nor was it detected in the three northern hemisphere occultation profiles retrieved from Magellan (Jenkins et al, 1994).…”

Microwave absorptivity by sulfuric acid in the Venus atmosphere: First results from the Venus Express Radio Science experiment VeRa

“…It was first used during the Mariner IV flyby of Mars in 1965 (Kliore et al, 1965) and developed further with the Mariner V observations of Venus in 1967(Mariner Stanford Group, 1967. Further observations of Venus with the radio occultation technique have been performed with the spacecraft Mariner 10 (Eshleman et al, 1980;Howard et al, 1974;Kliore et al, 1979;Lipa and Tyler, 1979), Pioneer Venus (Cimino et al, 1980;Jenkins and Steffes, 1991;Kliore and Patel, 1982), Venera 15/16 (Yakovlev et al, 1991;Gubenko et al, 2001Gubenko et al, , 2008, and Magellan Steffes et al, 1994). Observations of radio signals propagating through the Venus atmosphere to Earth are recorded at times prior to the start of the occultation of the spacecraft by Venus and during the emergence as seen from the Earth.…”

Small-scale temperature fluctuations seen by the VeRa Radio Science Experiment on Venus Express

“…Gravity waves inferred from radio occultation temperature profiles were observed by Pioneer Venus (Kliore and Patel, 1980;Woo et al, 1980Woo et al, , 1982, Venera 9 (Kolosov, 1980;Timofeeva et al, 1978), Venera 15 and 16 (Yakovlev et al, 1991) and Magellan (Hinson and Jenkins, 1995). These gravity waves are believed to play an important role in the momentum balance of the superrotating atmosphere even though their detailed function in the overall process is not fully understood (Hou and Farrell, 1987;Gierasch, 1987;Leroy and Ingersoll, 1995;Bougher et al, 2006;Lebonnois et al, 2010).…”