Ingersoll A P, Kanamori H
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena 91125, USA.
Nature. 1995 Apr 20;374(6524):706-8. doi: 10.1038/374706a0.
Observations of the collisions of the fragments of comet Shoemaker-Levy 9 with Jupiter provided an unprecedented opportunity to probe the depths of the planet's atmosphere. Images taken by the Hubble Space Telescope revealed circular rings surrounding five of the impact sites. The rings were observed for up to 2.5 hours after the impacts and spread at a constant velocity of 450 m s-1. There are three types of disturbance that might explain these observations: acoustic waves trapped at the tropopause temperature minimum, gravity waves propagating vertically and horizontally in the stratosphere, and gravity waves trapped in a stable layer which acts as a horizontal waveguide and is located within the hypothesized tropospheric water cloud. Here we show that only the last of these phenomena can match the speed and relative amplitude of the observed waves, with the requirement that the impacts were deep and the stability of the trapping layer is large. The origin of the stable layer is still uncertain, but if it is produced by moist convection in the water cloud, then the ratio of oxygen to hydrogen on Jupiter must be surprisingly large--approximately ten times that on the Sun.
对苏梅克-列维9号彗星碎片与木星碰撞的观测提供了一个前所未有的机会来探测木星大气层的深处。哈勃太空望远镜拍摄的图像显示，五个撞击点周围有圆形光环。撞击后，这些光环被观测到长达2.5小时，并以450米/秒的恒定速度扩散。有三种类型的扰动可能解释这些观测结果：被困在对流层顶温度最低点的声波、在平流层中垂直和水平传播的重力波，以及被困在一个稳定层中的重力波，该稳定层充当水平波导，位于假设的对流层水云内。在这里，我们表明，只有这些现象中的最后一种能够与观测到的波的速度和相对振幅相匹配，条件是撞击深度较大且捕获层的稳定性较大。稳定层的起源仍然不确定，但如果它是由水云中的湿对流产生的，那么木星上氧与氢的比例必定出奇地大——大约是太阳上的十倍。
