Dual sounding rocket observations of low‐altitude electrostatic shocks
Dual sounding rocket observations of low‐altitude electrostatic shocks
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双探空火箭低空静电冲击观测
DOI：
10.1029/ja095ia08p12173
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
F. Mozer
中科院分区：
文献类型：
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作者：
M. Boehm;C. Carlson;J. Mcfadden;F. Mozer
1984 年 2 月 7 日，两枚探空火箭几乎同时从阿拉斯加的扑克滩和育空堡发射到深夜的极光区，将两个有效载荷同时放置在几乎相同的磁力线上。 Black Brant X 有效载荷的远地点为 1040 公里，测量到的直流电场约为 300 mV/m，而海拔较低的 Terrier-Malemute 有效载荷（远地点为 640 公里）仅测量到低于 100 mV/m 的典型电离层电场。这些测量意味着比较高有效载荷低几kV的并联电势，最有可能发生在两个有效载荷之间。并联电势的精确值取决于电势结构相对于有效负载的运动。有一些证据表明电子数据中的有效负载之间存在约 2 kV 的电位降。还暗示了非绝热电子轨迹。在 100 Hz 至 10 kHz 频段内没有观察到支持平行场的可能电阻机制。因此暗示在其他频率或探头未测量到的类型下存在产生阻力的湍流，或与有效载荷轨迹不一致的局部平行电势。在所有高度观察到明显的“次级粒子”意味着要么有数百电子伏的势垒将这些电子捕获在向上电场区域上方，要么次级粒子实际上是源自冷背景的局部加速电子。对于探空火箭来说，在 1000 公里处遇到的等离子体条件是不寻常的。在最高电场和最低密度期间，5.8 米天线测量到的直流电场明显大于 3 米天线。内部一致性检查、自旋相关波形的近正弦性质以及吊杆与有效载荷的 >10 λDebye 分离得出的结论是，较长的吊杆测量是正确的，有效载荷尾流干扰了较短的天线。
Two sounding rockets were launched near simultaneously into the late evening auroral zone from Poker Flat and Fort Yukon, Alaska, on February 7, 1984, placing two payloads on nearly the same magnetic field lines simultaneously. The Black Brant X payload, with an apogee of 1040 km, measured dc electric fields of ∼300 mV/m, while the lower altitude Terrier-Malemute payload (apogee 640 km) measured only typical ionospheric electric fields under ∼100 mV/m. These measurements imply a parallel potential of several kV below the higher payload, most probably occurring between the two payloads. The exact value of the parallel potential is dependent on the motion of the potential structure with respect to the payload. There is some evidence of an ∼2-kV potential drop between the payloads in the electron data. Nonadiabatic electron trajectories are also implied. No possible resistive mechanism to support the parallel field is observed in the 100-Hz to 10-kHz frequency band. The existence of resistance-producing turbulence at other frequencies or of a type not measured by the probes, or localized parallel potentials not coincident with the payload trajectories, are thus implied. The observation of apparent “secondaries” at all altitudes implies either a potential barrier of hundreds of electron volts that trapped these electrons above the region of upward electric field or that the secondaries were actually locally accelerated electrons originating out of the cold background. The plasma conditions encountered at 1000 km are unusual for sounding rockets. During the highest electric fields and lowest densities, a 5.8-m antenna measured significantly larger dc electric fields than a 3-m antenna. Internal consistency checks, the near-sinusoidal nature of the spin-dependent waveform, and the >10 λDebye separation of the booms from the payload lead to the conclusion that the longer boom measurements were correct, the payload wake having interfered with the shorter antennas.