The dynamics of Mars's polar vortices

项目描述：火星的大气与地球有许多相似之处；两颗行星都有从赤道输送热量和动量的哈德利细胞，而围绕两极的是被称为极地涡旋的强风带。然而，火星在许多方面也不同。在火星的冬季，温度变得如此之低，以至于大气的主要成分——二氧化碳——在两极的冰帽处凝结。此外，在极冠上还有惊人的冰、尘埃和其他微量物质的层状沉积物。这些可以被认为相当于地球上的冰芯或树木年轮；给了我们火星过去气候的记录。事实上，这是除了地球之外唯一已知的行星气候记录。该项目将探索火星极地涡旋的动力学与微量物种向极地地区的运输之间的联系，以期了解这种气候记录。我们将使用导师最近开发的一套数值模拟方法，以及理论和与航天器观测的比较。该项目将适合对流体动力学，行星大气和气候感兴趣的候选人，尽管不一定有经验。

Project Description:Mars's atmosphere has many similarities with Earth; both planets have Hadley cells which transport heat and momentum from the equator, while encircling the poles are bands of strong winds known as polar vortices. However, Mars is also different in many ways. In the Martian winter, temperatures become so cold that the main atmospheric constituent, carbon dioxide, condenses at the polar caps. Also at the polar caps are striking layered deposits of ice, dust, and other trace species. These can be thought of as equivalent to ice cores or tree rings on Earth; giving us a record of Mars's past climate. In fact, this is the only known climate record of a planet other than Earth.This project will explore links between the dynamics of the Martian polar vortices and the transport of trace species to polar regions, with a view to understanding this climate record. We will use a suite of numerical modelling approaches recently developed by the supervisors, along with theory and comparisons with spacecraft observations. The project will suit candidates with interests, though not necessarily experience, in fluid dynamics, planetary atmospheres, and climate.