ADIW02 | Prof. Antoine Venaille | Chaos in the stratosphere?

Speaker: Professor Antoine Venaille (ENS - Lyon) Date: 28th Mar 2024 - 11:30 to 12:20 Venue: INI Seminar Room 1 Title: Chaos in the stratosphere ? Event: (ADIW02) Mathematical and Computational Modelling of Anti-Diffusive Phenomena Abstract: For quite some time, the equatorial stratospheric winds have displayed a rhythmic pattern similar to a metronome, alternating approximately every 28 months: blowing westward along the equator for 14 months, then eastward for another 14 months, and so on. In 2016, this rhythmic pattern faltered, resembling a skipped beat. We will introduce the classical Holton-Lindzen-Plumb model, which helps elucidate these quasi-biennial oscillations. This model reveals that the oscillations are driven by internal wave Reynolds stresses, acting in an anti-diffusive manner by forming downward-propagating fronts. Within this framework, we will see how such regular oscillations can be destabalized, leading to the emergence of new dynamical regimes, and discuss physical mechanisms favoring the resurgence of periodic states. Joint work with X. Chartrand, L.-P. Nadeau, and A. Renaud. ------------------- FOLLOW US 🌐| Website: https://www.newton.ac.uk 🎥| Main Channel:    / @isaacnewtoninstitute   🐦| Twitter:   / newtoninstitute   💬| Facebook:   / newton.institute   📷| Instagram:   / isaacnewtoninstitute   🔗| LinkedIn:   / isaac-newton-institute-for-mathematical-sc...   SEMINAR ROOMS 🥇| INI Seminar Room 1:    / @iniseminarroom1   🥈| INI Seminar Room 2:    / @iniseminarroom2   🛰️| INI Satellite Events:    / @inisatellite   ABOUT The Isaac Newton Institute is a national and international visitor research institute. It runs research programmes on selected themes in mathematics and the mathematical sciences with applications over a wide range of science and technology. It attracts leading mathematical scientists from the UK and overseas to interact in research over an extended period. 👉 Learn more about us and our events here: https://www.newton.ac.uk