Aeronomical Effects of the Impact of Comet Shoemaker-Levy-9 with Jupiter

9322078克雷文斯彗星休梅克-利维9号预计将于1994年7月21-23日左右进入木星大气层。大量的水蒸气将被注入木星的上层大气。中性气体和电离层的光化学都将因这种水蒸气的流入或水的解离而产生的原子氧而发生极大的改变。与彗星水流入有关的奇数氧(即氧或水蒸气或羟基自由基)通过去除电离的氢离子来改变离子化学，这也具有降低电离层电子密度的效果，因为电离的氢通常是木星电离层中的主要离子物种。彗星水解离产生的氧原子也会与甲基自由基反应，最终在大气层更深处形成一氧化碳。PI有一个数值模型，最初是为了研究奇数氧对木星极光电离层的影响而开发的。他建议采用这个模型来研究彗星Shoemaker-Levy 9对木星热层和电离层的影响。这些影响(例如，电子密度的严重降低)在彗星撞击后甚至几年内都将是全球性和重大的，这将使伽利略航天器能够研究从这一事件中恢复的情况。***

9322078 Cravens Comet Shoemaker-Levy 9 is expected to enter the atmosphere of Jupiter on about July 21-23, 1994. Significant amounts of water vapor will be injected into the upper atmosphere of Jupiter. The photochemistry of both the neutral gas and the ionosphere will be greatly altered by the influx of this water vapor or the atomic oxygen generated by the dissociation of the water. The odd oxygen (i.e., oxygen or water vapor or the hydroxyl radical) associated with the cometary water influx alters the ion chemistry by removing ionized hydrogen ions, which also has the effect of reducing the ionospheric electron density because ionized hydrogen is ordinarily the main ion species in the Jovian ionosphere. The oxygen atoms from the dissociation of the cometary water will also react with the methyl radical and eventually form carbon monoxide deeper in the atmosphere. The PI has a numerical model that was originally developed to study the effects of odd oxygen on the auroral ionosphere of Jupiter. He proposes to adapt this model to study the effects of comet Shoemaker-Levy 9 on the thermosphere and ionosphere of Jupiter. These effects (e.g., severe reduction of electron density) will be both global and significant even a couple of years after the comet impact which will allow the Galileo spacecraft to study the recovery from this event. ***