Understanding polar vortices on Earth by looking at other planets

点击翻译按钮获取中文摘要

Polar vortices are highly dynamical features of the Earth's atmosphere, and pay a critical role in the stratosphere (10-50 km in altitude) where they result in the ozone hole in the southern hemisphere. When the vortex destabilises, it can also cause extremely cold weather at the surface, such as the winter of 2013/14 when the whole UK was covered in snow. While our knowledge of how the polar vortex evolves over time has advanced a lot in the last decade, there is still much we do not know. This includes possible persistent vortex states that have yet to have been observed. Hence, we can gain fundamental understanding of the vortex structure and evolution by considering polar vortices on other planets, many of which have been studied in isolation to some degree already, e.g. Mars, Venus, Saturn, Jupiter and Titan (a moon of Saturn). Project Aims and Methods:To compare the Martian atmospheric dynamics changes with Earth and other planetary bodies, thereby helping to build a fuller understanding of planetary atmosphere dynamics. Specifically, - To review our current understanding of Earth and planetary polar vortices.- To further develop our Mars global circulation model to reproduce a faithful Martian climate.- To implement CO2 condensation (an important process in Martian polar regions) in the model.- To perform parameter perturbations of Martian atmospheric parameters, to understand their influence on climate. The main tool used for this analysis will be the global circulation model Isca, developed primarily in Co-I Prof Vallis' team. Isca is a flexible 3D model that can be used to understand the atmospheric circulation of a range of terrestrial and gas planets, including all planets in our solar system, as well as Exo-planets. The model gives a faithful reproduction of Earth, and is ideal for comparing Earth-like circulations with other planetary circulations to further our understanding of fundamental atmospheric flow