We report the impact of the 2018 Mars global dust storm on the ionosphere, in particular, its peak altitude during the onset and growth phases of the event. A one‐dimensional photochemical model is applied to estimate the ionospheric electron densities below 200 km using the measurements of in situ neutral densities and ionizing solar radiation by the NASA Mars Atmosphere and Volatile EvolutioN (MAVEN) mission. Our model results show that while the peak density of the ionosphere on the dawn side during the dust storm is hardly impacted, the altitude of the peak layer may be lifted by ∼10 km. The simulation results support the MAVEN radio occultation observations that there is a time delay in the response of the ionospheric peak altitude in the southern hemisphere (SH), compared with the northern hemisphere (NH) during the dust storm development. Although the 2018 global dust storm developed in the northern Martian mid‐latitudes on 1 June and developed into a global dust event on 17 June, our study suggests that the impact on the ionospheric peak altitude near the equatorial and southern mid‐latitudes became important only after 22 June. This suggests that there was a time‐lag of about 3 weeks in the response of the Martian upper atmosphere of the SH to the dust storm that originated in the NH.

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2018年火星全球沙尘暴对电离层峰的影响：一项使用光化学模型的研究

我们报告了2018年火星全球沙尘暴对电离层的影响，特别是在事件开始和生长阶段其电离层的峰值高度。使用一维光化学模型，通过NASA火星大气和挥发挥发分（MAVEN）任务的原位中性密度和电离太阳辐射的测量，估算了200 km以下的电离层电子密度。我们的模型结果表明，尽管沙尘暴期间黎明一侧电离层的峰值密度几乎没有受到影响，但峰值层的高度可能会升高约10 km。模拟结果支持MAVEN无线电掩星观测，在沙尘暴发展过程中，与北半球（NH）相比，南半球（SH）的电离层峰值高度的响应存在时间延迟。尽管2018年的全球沙尘暴在6月1日在火星中纬度北部发展并在6月17日发展为全球沙尘事件，但我们的研究表明，对赤道和中南纬度附近的电离层峰值高度的影响仅变得重要6月22日之后。这表明，上海的火星高层大气对源自NH的沙尘暴的响应存在约3周的时间滞后。