Venus's Southern Polar Vortex Reveals Precessing Circulation

• Published in: Science
• Main Authors: Luz, David, Berry, D. L., Piccioni, Giuseppe, Drossart, Pierre, Politi, Romolo, Wilson, Colin F., Erard, Stéphane, Nuccilli, Fabrizio
• Other Authors: Centro de Astronomia e Astrofísica da Universidade de Lisboa, Observatório Astronómico de Lisboa (CAAUL), Departamento de Física, Universidade de Évora, Istituto di Astrofisica Spaziale e Fisica Cosmica (IASF-Roma), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Pôle Planétologie du LESIA, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Department of Physics, University of Oxford, Istituto di Fisica dello Spazio Interplanetario (IFSI), National Research Council of Italy
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]; South pole
• Online Access: https://hal.science/hal-03785886; https://doi.org/10.1126/science.1201629

International audience Initial images of Venus's south pole by the Venus Express mission have shown the presence of a bright, highly variable vortex, similar to that at the planet's north pole. Using high-resolution infrared measurements of polar winds from the Venus Express Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) instrument, we show the vortex to have a constantly varying internal structure, with a center of rotation displaced from the geographic south pole by ~3 degrees of latitude and that drifts around the pole with a period of 5 to 10 Earth days. This is indicative of a nonsymmetric and varying precession of the polar atmospheric circulation with respect to the planetary axis.