Lanzerotti LJ, Rinnert K, Dehmel G, Gliem FO, Krider EP, Uman MA, Bach J
L. J. Lanzerotti, Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, and the University of Florida, Gainesville, FL 32611, USA. K. Rinnert, Max-Planck-Institut fur Aeronomy, D-37191 Katlenburg-Lindau, Germany. G. Dehmel, F. O. Gliem, J. Bach, Universitat Braunschweig, D-38106 Braunschweig, Germany. E. P. Krider, University of Arizona, Tucson, AZ 85721, USA. M. A. Uman, University of Florida, Gainesville, FL 32611, USA.
Science. 1996 May 10;272(5263):858-60. doi: 10.1126/science.272.5263.858.
During the Galileo probe's descent through Jupiter's atmosphere, under the ionosphere, the lightning and radio emission detector measured radio frequency signals at levels significantly above the probe's electromagnetic noise. The signal strengths at 3 and 15 kilohertz were relatively large at the beginning of the descent, decreased with depth to a pressure level of about 5 bars, and then increased slowly until the end of the mission. The 15-kilohertz signals show arrival direction anisotropies. Measurements of radio frequency wave forms show that the probe passed through an atmospheric region that did not support lightning within at least 100 kilometers and more likely a few thousand kilometers of the descent trajectory. The apparent opacity of the jovian atmosphere increases sharply at pressures greater than about 4 bars.
在伽利略探测器穿过木星大气层、电离层下方的过程中，闪电与无线电发射探测器测量到的射频信号强度明显高于探测器的电磁噪声。在下降开始时，3千赫兹和15千赫兹处的信号强度相对较大，随着深度增加至约5巴的压力水平时信号强度降低，然后在任务结束前缓慢增加。15千赫兹的信号显示出到达方向的各向异性。射频波形测量表明，探测器在下降轨迹至少100公里、更可能是几千公里的范围内穿过了一个不支持闪电的大气区域。在压力大于约4巴时，木星大气层的表观不透明度急剧增加。
