Water Ice Clouds in the Atmosphere of Mars

火星的大气层中经常可以看到薄薄的水冰云，与地球不同的是，火星的温度低到足以形成二氧化碳冰云。该项目将使用开放大学火星全球环流模型来研究火星云循环[1]。尘埃、水蒸气和冰是由火星大气中的风输送的。它们通过吸收和发射辐射相互作用，进而影响大气温度和风型[2]。大气图1：2018年全球沙尘暴期间(左)和次年没有全球沙尘暴的情况下，来自火星气候探测仪的卫星观测到的水冰不透明度的纬度-海拔分布。温度决定了可凝聚物质冻结成冰或冰升华的位置，尘埃进一步发挥了冰粒凝结核的作用。2018年，火星经历了一次全球沙尘暴，当时地球大部分地区被全球范围的沙尘活动所产生的一层尘埃所覆盖。在这种极端事件期间，水蒸气和水冰云的分布被显著改变，导致水被输送到大气中比通常可能的高度高得多的地方。这种水的“抬升”被认为与火星大气层顶部的水的整体流失有关。了解水在一系列尘埃活动下的行为将允许计算几个火星年随时间推移的水分损失率

Thin water ice clouds are often seen in the atmosphere of Mars and, unlike Earth, temperatures reach sufficiently low for carbon dioxide ice clouds to form as well. This project will involve the use of the Open University Mars global circulation model to investigate the martian cloud cycle [1]. Dust, water vapour and ice are transported by winds in the martian atmosphere. They interact through absorbing and emitting radiation, affecting atmospheric temperatures and wind patterns in turn [2]. Atmospheric Figure 1: Satellite observations from the Mars Climate Sounder of the latitude-altitude distribution of water ice opacity during the 2018 global dust storm (left) and in the subsequent year with no global dust storm.temperatures determine where condensable species freeze into ice, or ice sublimates, and dust plays a further role as condensation nuclei for ice particles.In 2018, Mars experienced a global dust storm, when most of the planet was enshrouded in a layer of dust resulting from global-scale dust activity. During such extreme events, the distribution of water vapour and water ice clouds is modified significantly, resulting in the transport of water to much higher altitudes in the atmosphere than is normally possible. This 'uplift' of water is believed to be linked to the overall loss of water from the top of the atmosphere of Mars. Understanding the behaviour of water under a range of dust activity will allow water loss rates to be calculated over time for several Mars years