Fang Xiaohua, Pawlowski David, Ma Yingjuan, Bougher Stephen, Thiemann Edward, Eparvier Francis, Wang Wenbin, Dong Chuanfei, Lee Christina O, Dong Yaxue, Benna Mehdi, Elrod Meredith, Chamberlin Phillip, Mahaffy Paul, Jakosky Bruce
Laboratory for Atmospheric and Space Physics, University of Colorado Boulder, Boulder, CO, USA.
Physics and Astronomy Department, Eastern Michigan University, Ypsilanti, MI, USA.
Geophys Res Lett. 2019 Aug 28;46(16):9334-9343. doi: 10.1029/2019gl084515. Epub 2019 Aug 5.
We report the first global, time-dependent simulation of the Mars upper atmospheric responses to a realistic solar flare event, an X8.2 eruption on 10 September 2017. The Mars Global Ionosphere-Thermosphere Model runs with realistically specified flare irradiance, giving results in reasonably good agreement with the Mars Atmosphere and Volatile EvolutioN spacecraft measurements. It is found that the ionized and neutral regimes of the upper atmosphere are significantly disturbed by the flare but react differently. The ionospheric electron density enhancement is concentrated below ~110-km altitude due to enhanced solar X-rays, closely following the time evolution of the flare. The neutral atmospheric perturbation increases with altitude and is important above ~150-km altitude, in association with atmospheric upwelling driven by solar extreme ultraviolet heating. It takes ~2.5 hr past the flare peak to reach the maximum disturbance and then additional ~10 hr to generally settle down to preflare levels.
我们报告了首次针对现实太阳耀斑事件（2017年9月10日的一次X8.2级喷发）对火星高层大气响应进行的全球、随时间变化的模拟。火星全球电离层-热层模型在使用实际指定的耀斑辐照度情况下运行，得出的结果与火星大气与挥发物演化探测器的测量结果相当吻合。研究发现，高层大气的电离层和中性层受到耀斑的显著扰动，但反应有所不同。由于太阳X射线增强，电离层电子密度增强集中在约110公里高度以下，紧密跟随耀斑的时间演化。中性大气扰动随高度增加，在约150公里高度以上较为显著，这与太阳极紫外加热驱动的大气上升流有关。从耀斑峰值过去约2.5小时达到最大扰动，然后再经过约10小时总体恢复到耀斑前水平。
