A Comparative Study of Metallic Ions in the Atmospheres of Earth and Mars

由于行星际尘埃粒子的消融，金属被注入行星大气中。主要元素（铁、镁和钠）以原子和离子形式存在，是动力学和化学的优良示踪剂。这个项目将对比这些金属在火星和地球大气中的行为。在地球上，金属是通过地面激光雷达、火箭运载的质谱分析和卫星上的光谱仪来观测的。对于火星，美国国家航空航天局的MAVEN宇宙飞船提供了前所未有的对行星电离层大部分金属离子的测量。这是因为MAVEN的高椭圆轨道允许在异常低的高度取样。令人惊讶的是，金属离子的不同行为已经被观察到，这可能是由于（至少）两个因素：不像地球有永久磁场，火星只有一小块地壳磁性，主要在南半球；火星的大气是二氧化碳，而不是N2/O2。这个项目将使用地球和火星的全球全大气模型来理解为什么金属的行为如此不同。目的是提高我们对中性大气和电离大气之间耦合的理解。这样做的一个重要原因是了解太空天气对我们大气层的影响，包括短期扰动和长期气候影响。将采用的两个模型是WACCM-X，这是美国国家大气研究中心（Boulder， USA）的全大气群落气候模型的扩展版本，以及巴黎CNRS的LMD-Mars模型。这两种都可以在利兹获得。该项目将在以下方面提供高水平的专业科学培训：(i)应用世界领先的大气化学-气候模型；（ii）大型数据集的分析和综合；（iii）使用先进的高性能计算设施。

Metals are injected into planetary atmospheres by the ablation of interplanetary dust particles. The major species (Fe, Mg and Na) exist as atoms and ions that are excellent tracers of dynamics and chemistry. This project will contrast the behaviour of these metals in the Martian and terrestrial atmospheres. On Earth, metals are observed by ground-based lidar, rocket-borne mass spectrometry, and from optical spectrometers on satellites. For Mars, NASA's MAVEN spacecraft is providing unprecedented measurements of metallic ions over much of the planet's ionosphere. This is because MAVEN's highly elliptical orbit permits sampling to unusually low altitudes. Surprisingly different behaviour in the metal ions has been observed, which is probably due to (at least) two factors: unlike the Earth which has a permanent magnetic field, Mars only has patches of crustal magnetism mainly in the southern hemisphere; and Mars has a CO2 - rather than an N2/O2 - atmosphere.This project will used global whole-atmosphere models of Earth and Mars to understand why the metals behave so differently. The objective will be to improve our understanding of the coupling between the neutral and ionized atmosphere. An important reason for doing so is to understand the effects of space weather on our atmosphere, both short-term perturbations and longer-term climatic influences. The two models that will be employed are WACCM-X, an extended version of the Whole Atmosphere Community Climate Model from the National Center for Atmospheric Research (Boulder, USA), and the LMD-Mars model from the CNRS in Paris. Both are available at Leeds. This project will provide a high level of specialist scientific training in: (i) the application of world-leading atmospheric chemistry-climate models; (ii) analysis and synthesis or large datasets; (iii) use of advanced High Performance Computing facilities.