Radar Detectability Studies of Slow and Small Zodiacal Dust Cloud Particles. III. The Role of Sodium and the Head Echo Size on the Probability of Detection
Radar Detectability Studies of Slow and Small Zodiacal Dust Cloud Particles. III. The Role of Sodium and the Head Echo Size on the Probability of Detection
复制标题
慢速和小黄道尘埃云粒子的雷达可探测性研究。
DOI：
10.3847/1538-4357/aa775c
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发表时间：
2017
期刊：
影响因子：
--
通讯作者：
P. Pokorný
中科院分区：
文献类型：
--
作者：
D. Janches;N. Swarnalingam;J. Carrillo;J. Gómez;R. Marshall;D. Nesvorný;J. Plane;W. Feng;P. Pokorný
我们提出了一个关于小而慢的流星体通量的长期问题的前进道路，据信这是进入地球大气层的流星质量通量的主要部分。这样的流量，这是预测的动力学尘埃模型的黄道带云，是不明显的地面雷达观测。几十年来，这是由于用于流星观测的雷达缺乏探测这一群体的灵敏度，因为低速流星产生的电离量很小。由于采用了大功率和大孔径雷达，特别是Arecibo 430 MHz雷达进行流星头回波观测，这一假设受到了挑战。Janches等人开发了一种概率方法来估计这些雷达对流星的可探测性，并初步表明，根据目前对消融和电离的了解，与实际观测相比，这些粒子的探测率应该占主导地位一到两个数量级。在本文中，我们在我们的模型中包括了最近发表的实验室测量结果，这些结果表明：（1）在更宽的高度范围内，Na的烧蚀强度较小;（2）Na原子在空气中的电离概率β ip在低速时比最初认为的小两个数量级。通过应用这些结果，并使用一个有点小尺寸的HE雷达目标，我们提供了一个解决方案，调和这些意见与模型预测。
We present a path forward on a long-standing issue concerning the flux of small and slow meteoroids, which are believed to be the dominant portion of the incoming meteoric mass flux into the Earth’s atmosphere. Such a flux, which is predicted by dynamical dust models of the Zodiacal Cloud, is not evident in ground-based radar observations. For decades this was attributed to the fact that the radars used for meteor observations lack the sensitivity to detect this population, due to the small amount of ionization produced by slow-velocity meteors. Such a hypothesis has been challenged by the introduction of meteor head echo (HE) observations with High Power and Large Aperture radars, in particular the Arecibo 430 MHz radar. Janches et al. developed a probabilistic approach to estimate the detectability of meteors by these radars and initially showed that, with the current knowledge of ablation and ionization, such particles should dominate the detected rates by one to two orders of magnitude compared to the actual observations. In this paper, we include results in our model from recently published laboratory measurements, which showed that (1) the ablation of Na is less intense covering a wider altitude range; and (2) the ionization probability, β ip , for Na atoms in the air is up to two orders of magnitude smaller for low speeds than originally believed. By applying these results and using a somewhat smaller size of the HE radar target we offer a solution that reconciles these observations with model predictions.
流星烧蚀的化学模型
影响因子：
6.3
作者：
Vondrak T
通讯作者：
Vondrak T