Investigating the Influence of Open Crustal Magnetic Field Regions on the Martian Ionosphere

研究开放地壳磁场区域对火星电离层的影响

• 批准号: ST/G002320/1
• 负责人: James Wild
• 金额: $ 36.92万
• 依托单位: Lancaster University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2010
• 资助国家: 英国
• 起止时间: 2010 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=ST%2FG002320%2F1
• 关键词: Investigating; Influence; Open; Crustal; Magnetic

The hunt for life in the solar system is intimately linked to the search for water, found in abundance on Earth, but relatively scarce on the other 'Earth-like' planets in our solar system (i.e. Venus and Mars). Given their broadly similar densities and distances from the Sun, it is likely that the Earth-like planets were all formed from broadly similar material in the early solar nebula and that the currently observed differences are a result of the differing long-term evolution of each planet. In the case of Mars, the cessation of a magnetic dynamo and the resulting collapse of the planet's main magnetic field about 4 billion years ago are thought to have been major factors in the loss of atmospheric volatiles, such as water and carbon dioxide. This is due to the shielding effect a planetary magnetic field confers to the atmosphere and surface environment. The Earth's magnetic field typically holds the solar wind at a distance of around ten planetary radii from the atmosphere and ionosphere. However, in the case of Mars, the absence of a significant magnetic field has allowed the solar wind direct access the atmosphere/ionosphere and resulted in the loss of volatiles (such as water) from the planetary environment to interplanetary space. This study will investigate the interaction between regions of strong crustal magnetic field near the surface of Mars (remnants of Mars' original magnetic field) and the solar wind. In regions where the crustal field is oriented roughly vertically, the solar wind can gain access to the atmosphere and ionosphere, where it is thought to cause heating. This heating is likely to be responsible for bulges observed in the Martian ionosphere over regions of strong near-vertical crustal field by the Mars Express spacecraft and may result in upwelling 'fountains' of atmospheric material. This material can then interact with the solar wind and be ost from the planet, contributing to the continuing erosion of Mars' atmosphere. The proposed research will be accomplished using numerical modelling techniques first used to study the near-Earth space environment and applying them to the very different atmosphere, ionosphere and magnetic field of Mars. A computer model will be developed to solve time-dependent equations of continuity, momentum and energy balance along simplified cusp-like magnetic field lines for the densities, field-aligned fluxes and temperatures of a number of ion species and electrons common in the Martian ionosphere. The outcomes of this research can be validated by comparison with data returned from Mars orbiting spacecraft (e.g. ESA's Mars Express) and will have important implications for the forthcoming Mars exploration missions (including ExoMars), the evolution of the Martian environment and broader studies of exobiology.

太阳系中的生命追求与在地球上丰富发现的水的搜索密切相关，但在我们的太阳系（即维纳斯和火星）中相对较少的“地球状”行星相对较少。鉴于它们与太阳的密度和距离大致相似，因此在太阳星云的早期材料中，地球样的行星都可能均来自广泛的材料，并且当前观察到的差异是每个行星长期演化的结果。就火星而言，磁力发电机的停止以及大约40亿年前地球主磁场的崩溃被认为是大气挥发物损失的主要因素，例如水和二氧化碳。这是由于屏蔽效果赋予了行星磁场赋予大气和表面环境。地球的磁场通常将太阳风与大气和电离层大约十个行星半径的距离保持。但是，在火星的情况下，没有明显的磁场使太阳能风能直接进入大气/电离层，并导致挥发物（例如水）从行星环境到行星际空间的损失。这项研究将研究火星表面（火星原始磁场的残余）和太阳风附近强层磁场区域之间的相互作用。在大致垂直定向地壳场的区域中，太阳风可以进入大气和电离层，在那里被认为会导致加热。这种加热可能是由于火星快递航天器在火星电离层中观察到的凸起的凸起，并可能导致大气材料的上升“喷泉”。然后，该材料可以与太阳风相互作用，并与地球相互作用，从而导致火星大气的持续侵蚀。拟议的研究将使用最初用于研究近地太空环境的数值建模技术来完成，并将其应用于MARS的截然不同的气氛，电离层和磁场。将开发一个计算机模型，以解决沿着密度，田间对准的通量以及在火星电离层中常见的许多离子物种和电子的密度，与场对准的通量以及温度的连续性，动量和能量平衡的时间相关方程。这项研究的结果可以通过与从火星旋转航天器（例如ESA的MARS Express）返回的数据进行比较来验证，并将对即将到来的MARS勘探任务（包括Exomars），火星环境的进化和更广泛的外生物学研究具有重要意义。

项目成果

Properties of a large-scale flux rope and current sheet region on the dayside of Mars: MGS MAG/ER and MEX ASPERA-3 ELS observations

• DOI: 10.1016/j.icarus.2014.08.019
• 发表时间: 2014-11
• 期刊: Icarus
• 影响因子: 3.2
• 作者: Y. Soobiah;J. Wild;M. Beharrell;S. Barabash;R. Lillis;D. Mitchell;A. Coates;J. Winningham

The morphology of the topside ionosphere of Mars under different solar wind conditions: Results of a multi-instrument observing campaign by Mars Express in 2010

• DOI: 10.1016/j.pss.2015.10.013
• 发表时间: 2016
• 期刊: Planetary and Space Science
• 影响因子: 2.4
• 作者: P. Withers;M. Matta;M. Lester;D. Andrews;N. Edberg;H. Nilsson;H. Opgenoorth;S. Curry;R. Lillis;E. Dubinin;M. Fraenz;X. Hang;Wlodek Kofman;Li Lei;D. Morgan;M. Paetzold;K. Peter;A. Opitz;J. Wild;O. Witasse