中层顶金属层的观测与模式研究
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摘要
本文旨在研究中层顶金属层的行为特征和变化规律背后蕴藏的物理机制,重点研究了中层顶金属物质的源——流星消融——对金属层的潜在影响。并尝试解释了目前金属层中一些尚无定论或尚存争议的问题。本文主要研究内容如下：
1通过武汉(30°N)在过去几年内的长期Na和Fe激光雷达测量,我们展示了高高度偶发金属原子层的季节／周年变化特征。我们发现出现在105 km以上的高高度偶发Na层和偶发Fe层几乎只出现在夏季。从形态上看,它们具有较长的持续时间(几个小时)和较宽的层宽(明显超过2 km)。在少数夜晚,它们的绝对峰值密度可以相比或甚至超过相应的主层峰值密度。在并未排除所有包含偶发层剖面的情况下,我们建立了30°N的Na和Fe原子密度随月份和高度分布的等值线图。从图上可以看到,Na和Fe层同时具有明显的夏季层顶密度延伸,这与早期其它纬度的K和Ca层观测结果一致。由于这些观测代表了不同的金属种类、不同的地理位置和不同的测量年份,平均金属原子层密度的夏季层顶延伸可能代表了一个普适现象。通过我们的研究发现,这个现象是由105 km以上的高高度偶发金属原子层引起的。
2使用共振荧光雷达,我们在武汉(30.5°N,114.4°E)于2001年(Na)和2004年(Na和Fe)狮子座流星雨期间开展了金属层的观测。2001年11月18-19日出现的流星雨强爆发导致我们捕捉到了一个强的Na原子流星尾迹。然而,观测发现流星雨的消融不太可能造成Na原子柱密度的提升。三年后的同一个夜晚,在较为平静的2004年狮子座流星雨期间,我们没有捕捉到尾迹但却看到了复杂的偶发金属层。偶发Na和Fe层于狮子座流星雨辐射点升上地平面后出现在95 km高度附近。比较发现,92 km以上Na和Fe原子的柱密度过午夜后均出现明显提升。同时,该晚Na和Fe原子柱密度相比前一晚要大得多。在狮子座期间的总共四个观测夜晚里,有三个夜晚出现了类似的偶发层。它们具有相似的出现时间、出现高度和高度变化。当前的彗星理论认为狮子座流星雨除了包含能够产生可见流星的流星体还包括了微流星。以此我们认为地球在2004年狮子座流星雨期间可能遭遇到了密集的小尺度微流星体群,它们也隶属于狮子座流星雨。这些微流星体的质量通量可能比可视流星雨大得多。
3我们建立了包含电荷过程和溅射作用的单个流星体消融模型。通过该模型可以模拟出单个流星体消融出来的金属原子和离子各自随高度的分布。同时,还建立了流星尾迹的质量与温度变化模型。这些模型为研究流星消融与金属层的关系提供了基础。基于可靠的偶发流星源的参数,我们模拟了中间层和低热层区域由偶发流星提供的金属原子平均注入的时间变化。并惊奇地发现模拟的金属原子注入与多个不同纬度观测的金属原子密度在一定条件下展示了相似的年平均周日变化和周日平均季节变化规律。鉴于目前已知的因素均不能解释金属原子的年平均周日变化,我们做如下猜测：一些短生命周期的原子(不长于几个小时)决定了金属原子密度的平均周日变化,而其它传统的长生命周期原子(约几天)提供了一个近似恒定的背景密度。两种原子共同组成了我们的金属层。很明显,这些预测存在的短生命周期原子需要一个快速的汇,且其主要作用于新消融不久的金属原子。这个汇的机制还不清楚但可能和消融产生的高温有关。
This dissertation aims mainly at researching the physical mechanisms behind the behavior and variation characteristics of mesopause metal layers. It particularly focuses on the potential influence of meteor ablation on metal layers, which is the source of mesopause metal materials. This dissertation also attempts to explain some unsolved and controversial questions about metal layers. The main contents are listed as followed:
1. The seasonal/annual characteristics of the high-altitude sporadic metal atom layers are presented on the basis of extensive Na and Fe lidar measurements at 30°N during the past several years. It is found that the extremely high sporadic Na (Nas) and Fe (Fes) layers above 105 km occurred mostly during summer. They had long durations (a few hours) and broad layer widths (much larger than 2 km). Their absolute peak densities could be comparable to or even larger than those of the corresponding main layers on a few nights. By using all the raw data profiles including sporadic layers, we have constructed the contour plots of Na and Fe densities versus month and altitude at 30°N. The Na and Fe layers both exhibit evidence for summer topside extension, which is consistent with the earlier observations for K and Ca at different latitudes. The summer topside extension of mean metal atom layers might represent a universal phenomenon that is alike for different atom species, different geographic locations and different measurement years. The extremely high sporadic metal atom layers above 105 km occurring during summer give rise to the phenomenon.
2. Using the resonance fluorescence lidars, we have carried out observations of metal layers during 2001 (Na) and 2004 (Na and Fe) Leonid meteor showers at Wuhan (30.5°N,114.4°E), China. The strong outburst of Leonid shower on 18-19 November 2001 resulted in our capture of a strong Na atom meteor trail. However, there was unlikely to exist any corresponding enhancement of Na column density by the ablation of meteor shower. On the same night three years later, during the calm 2004 Leonid shower, we captured no meteor trail but saw complex sporadic Na and Fe layer events around 95 km after the radiant of Leonid shower rose above the horizon. By comparison, the column densities above 92 km of both Na and Fe atoms showed prominent enhancements after midnight. In addition, the Na and Fe column densities on this night were much bigger than those on the night one day earlier. Among a total of four night observations during Leonid shower, the sporadic layers were observed on three nights. They appeared at similar time and altitude as well as moved with similar tendencies. Current cometary theory supports that Leonid meteor shower could contain both meteoroids that would produce visual meteors and micrometeoroids. Based on this knowledge, we consider that the Earth in 2004 may encounter a large swarm of small-sized micrometeoroids which belong to the Leonid meteor shower. The mass flux of these micrometeoroids might be much higher than that of the visual meteor shower.
3. We establish the single meteoroid ablation model, which has taken into account the charging and sputtering processes besides some traditional factors. With this model, we can calculate the ablation profiles of both ablated metal atoms and ions. Also, we have modeled the mass and temperature evolutions of an ablated meteor trail. These models provide a basis for researching the relations between meteoric ablation and metal layers. Based on reliable parameters of sporadic meteoroid sources, we have modeled the temporal variation of mean metal atoms input in the mesosphere and lower thermosphere (MLT) region. Surprisingly, the annual mean diurnal variation of modeled atoms input shows similar to that of observed atoms density under certain condition. As none of known factors are found to be the reason for the mean diurnal variation of atoms density, we have made the following conjecture. Some short-lifetime (no longer than several hours) atoms dominate the mean diurnal variation of atoms density and the other traditional long-lifetime (several days) ones provide a nearly constant background density. The two together compose our metal layers. Obviously, these predicted short-lifetime atoms need a fast sink mechanism, which acts mainly on the newly ablated atoms. The mechanism is not clear but may have relation to high temperature caused by ablation.
1通过武汉(30°N)在过去几年内的长期Na和Fe激光雷达测量,我们展示了高高度偶发金属原子层的季节／周年变化特征。我们发现出现在105 km以上的高高度偶发Na层和偶发Fe层几乎只出现在夏季。从形态上看,它们具有较长的持续时间(几个小时)和较宽的层宽(明显超过2 km)。在少数夜晚,它们的绝对峰值密度可以相比或甚至超过相应的主层峰值密度。在并未排除所有包含偶发层剖面的情况下,我们建立了30°N的Na和Fe原子密度随月份和高度分布的等值线图。从图上可以看到,Na和Fe层同时具有明显的夏季层顶密度延伸,这与早期其它纬度的K和Ca层观测结果一致。由于这些观测代表了不同的金属种类、不同的地理位置和不同的测量年份,平均金属原子层密度的夏季层顶延伸可能代表了一个普适现象。通过我们的研究发现,这个现象是由105 km以上的高高度偶发金属原子层引起的。
2使用共振荧光雷达,我们在武汉(30.5°N,114.4°E)于2001年(Na)和2004年(Na和Fe)狮子座流星雨期间开展了金属层的观测。2001年11月18-19日出现的流星雨强爆发导致我们捕捉到了一个强的Na原子流星尾迹。然而,观测发现流星雨的消融不太可能造成Na原子柱密度的提升。三年后的同一个夜晚,在较为平静的2004年狮子座流星雨期间,我们没有捕捉到尾迹但却看到了复杂的偶发金属层。偶发Na和Fe层于狮子座流星雨辐射点升上地平面后出现在95 km高度附近。比较发现,92 km以上Na和Fe原子的柱密度过午夜后均出现明显提升。同时,该晚Na和Fe原子柱密度相比前一晚要大得多。在狮子座期间的总共四个观测夜晚里,有三个夜晚出现了类似的偶发层。它们具有相似的出现时间、出现高度和高度变化。当前的彗星理论认为狮子座流星雨除了包含能够产生可见流星的流星体还包括了微流星。以此我们认为地球在2004年狮子座流星雨期间可能遭遇到了密集的小尺度微流星体群,它们也隶属于狮子座流星雨。这些微流星体的质量通量可能比可视流星雨大得多。
3我们建立了包含电荷过程和溅射作用的单个流星体消融模型。通过该模型可以模拟出单个流星体消融出来的金属原子和离子各自随高度的分布。同时,还建立了流星尾迹的质量与温度变化模型。这些模型为研究流星消融与金属层的关系提供了基础。基于可靠的偶发流星源的参数,我们模拟了中间层和低热层区域由偶发流星提供的金属原子平均注入的时间变化。并惊奇地发现模拟的金属原子注入与多个不同纬度观测的金属原子密度在一定条件下展示了相似的年平均周日变化和周日平均季节变化规律。鉴于目前已知的因素均不能解释金属原子的年平均周日变化,我们做如下猜测：一些短生命周期的原子(不长于几个小时)决定了金属原子密度的平均周日变化,而其它传统的长生命周期原子(约几天)提供了一个近似恒定的背景密度。两种原子共同组成了我们的金属层。很明显,这些预测存在的短生命周期原子需要一个快速的汇,且其主要作用于新消融不久的金属原子。这个汇的机制还不清楚但可能和消融产生的高温有关。
This dissertation aims mainly at researching the physical mechanisms behind the behavior and variation characteristics of mesopause metal layers. It particularly focuses on the potential influence of meteor ablation on metal layers, which is the source of mesopause metal materials. This dissertation also attempts to explain some unsolved and controversial questions about metal layers. The main contents are listed as followed:
1. The seasonal/annual characteristics of the high-altitude sporadic metal atom layers are presented on the basis of extensive Na and Fe lidar measurements at 30°N during the past several years. It is found that the extremely high sporadic Na (Nas) and Fe (Fes) layers above 105 km occurred mostly during summer. They had long durations (a few hours) and broad layer widths (much larger than 2 km). Their absolute peak densities could be comparable to or even larger than those of the corresponding main layers on a few nights. By using all the raw data profiles including sporadic layers, we have constructed the contour plots of Na and Fe densities versus month and altitude at 30°N. The Na and Fe layers both exhibit evidence for summer topside extension, which is consistent with the earlier observations for K and Ca at different latitudes. The summer topside extension of mean metal atom layers might represent a universal phenomenon that is alike for different atom species, different geographic locations and different measurement years. The extremely high sporadic metal atom layers above 105 km occurring during summer give rise to the phenomenon.
2. Using the resonance fluorescence lidars, we have carried out observations of metal layers during 2001 (Na) and 2004 (Na and Fe) Leonid meteor showers at Wuhan (30.5°N,114.4°E), China. The strong outburst of Leonid shower on 18-19 November 2001 resulted in our capture of a strong Na atom meteor trail. However, there was unlikely to exist any corresponding enhancement of Na column density by the ablation of meteor shower. On the same night three years later, during the calm 2004 Leonid shower, we captured no meteor trail but saw complex sporadic Na and Fe layer events around 95 km after the radiant of Leonid shower rose above the horizon. By comparison, the column densities above 92 km of both Na and Fe atoms showed prominent enhancements after midnight. In addition, the Na and Fe column densities on this night were much bigger than those on the night one day earlier. Among a total of four night observations during Leonid shower, the sporadic layers were observed on three nights. They appeared at similar time and altitude as well as moved with similar tendencies. Current cometary theory supports that Leonid meteor shower could contain both meteoroids that would produce visual meteors and micrometeoroids. Based on this knowledge, we consider that the Earth in 2004 may encounter a large swarm of small-sized micrometeoroids which belong to the Leonid meteor shower. The mass flux of these micrometeoroids might be much higher than that of the visual meteor shower.
3. We establish the single meteoroid ablation model, which has taken into account the charging and sputtering processes besides some traditional factors. With this model, we can calculate the ablation profiles of both ablated metal atoms and ions. Also, we have modeled the mass and temperature evolutions of an ablated meteor trail. These models provide a basis for researching the relations between meteoric ablation and metal layers. Based on reliable parameters of sporadic meteoroid sources, we have modeled the temporal variation of mean metal atoms input in the mesosphere and lower thermosphere (MLT) region. Surprisingly, the annual mean diurnal variation of modeled atoms input shows similar to that of observed atoms density under certain condition. As none of known factors are found to be the reason for the mean diurnal variation of atoms density, we have made the following conjecture. Some short-lifetime (no longer than several hours) atoms dominate the mean diurnal variation of atoms density and the other traditional long-lifetime (several days) ones provide a nearly constant background density. The two together compose our metal layers. Obviously, these predicted short-lifetime atoms need a fast sink mechanism, which acts mainly on the newly ablated atoms. The mechanism is not clear but may have relation to high temperature caused by ablation.
引文
Alpers, M., Blix, T., Kirkwood, S., Krankowsky, D., Lubken, F. J., Lutz, S., and von Zahn, U., First simultaneous measurements of neutral and ionized iron densities in the upper mesosphere., J. Geophys. Res.,1993,98,275-283.
Alpers, M., Hoffner, J., and von Zahn, U., Upper atmosphere Ca and Ca+at mid-latitudes:First simultaneous and common-volume lidar observations, Geophys. Res. Lett.,1996,23,567-570.
Anderson, H. H., and Bay, H. L., Sputtering Yield Measurments. In:Behrisch, R. (Ed.), Sputtering by Particle Bombardment, Springer-Verlag, Berlin,1981.
Appleton, E. V., and Naismith, R., Radio detection of Meteor trails and allied phenomena, Proc. Roy. Soc.,1947, A59,461-472.
Argall, P. S., and Sica, R. J., A comparison of Rayleigh and sodium lidar temperature climatologies, Ann. Geophys.,2007,25(1),27-35.
Asher, D. J., Leonid dust trail theories, Proc. International Meteor Conference, Frasso Sabino (ed. Arlt, R.),1999.
Asher, D. J., Bailey, M. E., and Emel'Yanenko, V. V., Resonant meteoroids from Comet Tempel-Tuttle in 1333:the cause of the unexpected Leonid outburst in 1998, Mon. Not. R. Astron. Soc.,1999,304(4), L53-L56.
Baggaley, W. J., Bennett, R. G. T., Steel, D. I., and Taylor, A. D.:Advanced Meteor Orbit Radar:AMOR, Qt. Jl. R. Astr. Soc.,1994,35,293-320.
Baggaley, W. J., Advanced meteor orbit radar observations of interstellar meteoroids, Journal of Geophysical Research,2000,105(A5),10353-10361.
Baggaley, W. J., Radar observations, in Meteors in the Earth's Atmosphere, edited by E. Murad and I. P. Williams, Cambridge Univ. Press, New York,2002,123-148.
Batista, P. P., Clemesha, B. R., Batista, I. S., and Simonich, D. M., Characteristics of the sporadic sodium layers observed at 23 degree S, Journal of Geophysical Research,1989,94,15349-14358.
Batista, P. P., Clemesha, B. R., and Simonich, D. M., Horizontal structures in sporadic sodium layers at 23 degrees south, Geophysical Research Letters,1991,18, 1027-1030.
Benzenberg, J. F., and Brandes, H. W., Versuch die Entfernung, die Geschwindigkeit und die Bahn der Sternschnuppen zu bestimmen, Annalen der Phys.,1800,6, 224-232.
Bernard, R., The identification and the origin of atmospheric sodium, Astrophysical Journal,1939,89,133-135.
Bohdansky, J., A universal relation for the sputtering yield of monoatomic solids at normal incidence, J. Nucl. Instr. Met. Phys. Res. B.,1984,2,587-591.
Bohdansky, J., Yield data for Tokamaks-A comparison of measurments and estimates, J. Nucl. Mater.,1980,93-94,44-60.
Borovicka, J., Elemental Abundances in Leonid and Perseid Meteoroids, Earth, Moon, and Planets,2005, Volume 95, Numbers 1-4,245-253(9).
Borovicka, J., Two components in meteor spectra, Planet. Space Sci., February 1994, 42(2),145-150.
Bowman, M. R., Gibson, A. J., and Sandford, M. C., Atmospheric Sodium Measured by a Tuned Laser Radar, Nature,1969,221,456-458.
Bronshten, V. A., Physics of Meteoric Phenomena, D. Reidel Pub. Co., Dordrecht, 1983,91,265.
Brown, P., and Jones, J., A determination of the strengths of the sporadic radio-meteor sources, Earth, Moon and Planets,1995,68,223-245.
Ceplecha, Z., Borovicka, J., Elford, W.G., ReVelle, D.O., Hawkes, R.L., Porubcan, V., and Simek, M., Meteor phenomena and bodies, Space Sci. Rev.,1998,84, 327-471.
Chu, X., Liu, A. Z., Papen, G., Gardner, C. S., Kelley, M., Drummond, J., and Fugate, R., Lidar observations of elevated temperatures in bright chemiluminescent meteor trails during the 1998 Leonid Shower, Geophysical Research Letters,2000,27(13), 1815-1818.
Chu, X., Pan, W., Papen, G., Gardner, C. S., Swenson, G., and Jenniskens, P., Characteristics of Fe ablation trails observed during the 1998 Leonid meteor shower, Geophysical Research Letters,2000,27(13),1807-1810.
Clemesha, B. R., Kirchhoff, V. W. J. H., Simonich, D. M., and Takahashi, H., Evidence of an extra-terrestrial source for mesospheric sodium layer, Geophys. Res. Lett.,1978,5,873-876.
Clemesha, B. R., Batista, P. P., and Simonich, D. M., Concerning the origin of enhanced sodium layers, Geophys. Res. Lett.,1988,15(11),1267-1270.
Clemesha, B. R., Sporadic neutral metal layers in the mesosphere and lower thermosphere, J. Atmos. Terr. Phys.,1995,57(7),725-736.
Clemesha, B. R., Batista P. P., and Simonich, D. M., An evalution of the evidence for ion recombination as a source of sporadic neutral layers in the lower thermosphere, Adv. Space Res.,1999,24,541-556.
Collins, R. L., Hallinan, T. J., Smith, R. W., and Hernandez, G., Lidar observations of a large high-altitude sporadic Na layer during active aurora, Geophysical Research Letters,1996,23(24),3655-3658.
Cziczo, D. J., Thomson, D. S., and Murphy, D. M., Ablation, flux, and atmospheric implications of meteors inferred from stratospheric aerosol, Science,2001,291, 1772-1775.
Dyrud, L. P., Oppenheim, M. M., and vorn Endt, A. F., The anomalous diffusion of meteor trails, Geophysical Research Letters,2001,28(14),2775-2778.
Elkin, W. L., The Velocity of Meteors as Deduced from Photographs at the Yale Observatory, Ap. J.,1900,12,4-7.
Ellyett, C. D., and Davies, J. G., Velocities of meteor measured by Diffraction of Radio Waves from Trails during formation, Nature,1948,161,596-597.
Ellyett, C. D., The daytime meteor streams of 1949:measurement of velocities, Mon. Not. R. Astr. Soc.,1949,109,359-364.
Fan, Z. Y., Plane, J. M. C., Gumbel, J., Stegman, J., and Llewellyn, E. J., Satellite measurements of the global mesospheric sodium layer, Atmos. Chem. Phys.,2007, 7,4107-4115.
Friedman, J. S., Gonzalez, S. A., Tepley, C. A., Zhou, Q., and Sulzer, M. P., Simultaneous atomic and ion layer enhancements observed in the mesopause region during the Coqui Ⅱ sounding rocket campaign, Geophys. Res. Lett.,2000, 27(4),449-452.
Galligan, D. P., and Baggaley, W. J., The radiant distribution of AMOR radar meteors, Mon. Not. R. Astron. Soc.,2005,359(2),551-560.
Gardner, C. S., Plane, J. M. C., Pan, W., Vondra, T., Murray, B. J., and Chu, X., Seasonal variations of the Na and Fe layers at the South Pole and their implications for the chemistry and general circulation of the polar mesosphere, Journal of Geophysical Research,2005,110, D10302, doi:10.1029/2004JD005670.
Gerding, M., Alpers, M., Hoffner, J., and von Zahn, U., Sporadic Ca and Ca+layers at mid-latitudes:Simultaneous observations and implications for their formation, Annales Geophysicae,2001,19,47-58.
Gerding, M., Alpers, M., Hoffner, J., and von Zahn, U., Simultaneous K and Ca lidar observations during a meteor shower on March 6-7,1997, at Kuhlungsborn, Germany, Journal of Geophysical Research,1999,104(A11),24689-24698.
Gibson, A. J., and Sandford, M. C. W., The seasonal variation of the night-time sodium layer, Journal of Atmospheric and Terrestrial Physics,1971,33, 1675-1684.
Gong, S. S., Yang, G. T., Wang, J. M., Cheng, X. W., Li, F. Q., and Wan, W. X., A double sodium layer event observed over Wuhan, China by lidar, Geophysical Research Letters,2003,30(5),1209-1212, doi:10.1029/2002GL016135.
Hoffner, J., Friedman, J.S., The mesospheric metal layer topside:a possible connection to meteoroids. Atmospheric Chemistry and Physics,2004,4,801-808.
Hoffner, J., Friedman, J.S., The mesospheric metal layer topside:Examples of simultaneous metal observations. Journal of Atmospheric and Solar-Terrestrial Physics,2005,67,1226-1237.
Hansen, G., and von Zahn, U., Sudden sodium layers in polar latitudes, J. Atmos. Terr. Phys.,1990,52,585-608.
Harvey, G. A., Elemental abundance determinations for meteors by spectroscopy, J. Geophys. Res.,1973,78,3913-3926.
Helmer, M., Plane, J. M. C., Qian, J., and Gardner, C. S., A model of meteoric iron in the upper atmosphere, J. Geophys. Res.,1998,103,10913-10926.
Herlofson, N., The theory of meteor ionization, Proc. Phys. Soc.,1946,11,444-445.
Hey, J. S., and Stewart G. S., Derivation of meteor stream radiants by radio reflex methods, Nature,1946,158,481-483.
Hey, J. S., Parsons, S. J., and Stewart, G. S., Radio observations of the Giacobinid Meteor shower,1946, Mon.Not. R. Astr. Soc.,1947,107,176-183.
Hey, J. S., and Stewart, G. S., Radar observations of meteors, Proc. Phys. Soc.,1947, 59,858-883.
Hughes, D. W., Meteors. In, Cosmic Dust, edited by McDonnell, J. A. M., Wiley, London,1978,123-185.
Hughes, D. W., Meteors and cosmic dust, Endeavour,1997,21,31-35.
Hunten, D. M., Turco, R. P., and Toon, O. B., Smoke and dust particles of the meteoric origin in the mesosphere, J. Atmos. Sci.,1980,37,1342-1357.
International Meteor Organization, http://www.imo.net.
Janches, D., Mathews, J. D., Meisel, D., and Zhou, Q., Orbital properties of the Arecebo micrometeorites at Earth intersection, Icarus,2001,150,206-218.
Janches, D., Nolan, M. C., Meisel, D. D., Mathews, J. D., Zhou, Q. H., and Moser, D. E., On the geocentric micrometeor velocity distribution, J. Geophys. Res.,2003, 108(A6),1222, doi:10.1029/2002JA009789.
Janches, D., and Chau, J. L., Observed diurnal and seasonal behavior of the micrometeor flux using the Arecibo and Jicamarca radars, J. Atmos. Solar Terr. Phys.,2005,67,1196-1210.
Janches, D., Mathews, J. D., Meisel, D. D., Getman, V. S., Zhou, Q. H., Doppler studies of near-antapex UHF radar micrometeors, Icarus,2000,143,347-353.
Janches, D., Heinselman, C. J., Chau, J. L., Chandran, A., and Woodman, R., Modeling the global micrometeor input function in the upper atmosphere observed by high power and large aperture radars, J. Geophys. Res.,2006,111, A07317, doi:10.1029/2006JA011628.
Jones, W, Monthly Notices of the Royal Astronomical Society,1997,288,995.
Kane, T. J., Hostetler, C. A., and Gardner, C. S., Horizontal and vertical structure of the major sporadic sodium layer events observed during ALOHA-90, Geophysical Research Letters,1991,18(7),1365-1368.
Kane, T. J., Gardner, C. S., Zhou, Q., Mathews, J. D., and Tepley, C. A., Lidar, radar and airglow observations of a prominent sporadic Na/sporadic E layer event at Arecibo during AIDA-89, Journal of Atmospheric and Terrestrial Physics,1993,55, 499-511.
Kresak, L., Meteor storms. In meteoroids and their Parent Bodies, eds Stohl J. and Williams I.P., Slovak Academy of Sciences, Bratislava,1993,147-156.
Liu, Y., and Yi, F., Bahavior of sporadic Na layers on small time scale, J. Atmos. Solar Terr. Phys.,2009,71,1374-1382.
Love, S. G., and Brownlee, D. E., Heating and thermal transformation of micrometeoroids entering the Earth's atmosphere, Icarus,1991,89,26-43.
Lovell, A. C. B., Banwell, C. J., and Clegg, J. A., Radio Echo Observations of the Giacobinid Meteors 1946, Mon. Not. R. Astr. Soc.,1947,107,164-175.
Lynch, K. A., Gelinas, L. J., Kelley, M. C., Collins, R. L., Widholm, M., Rau, D., MacDonald, E., Liu, Y, Ulwick, J., and Mace, P., Multiple sounding rocket observations of charged dust in the polar winter mesosphere, J. Geophys. Res., 2005,110, A03302, doi:10.1029/2004JA010502.
Ma, Y. H., and He, Y. W., The Third peak of the 1998 Leonid Meteor Shower, Chinese Journal of Astronomy and AstroPhysics,2001,1(3),271-274.
Ma, Z., and Yi, F., High-altitude sporadic metal atom layers observed with Na and Fe lidars at 30°N, Journal of Atmospheric and Solar-Terrestrial Physics,2010,72, 482-491.
Mathews, J. D., Zhou, Q., Philbrick, C. R., Morton, Y. T., and Gardner, C. S., Observations of ion and sodium layer coupled processes during AIDA, J. Atmos. Terr. Phys.,1993,55,487-498.
Mathews, J. D., Janches, D., Meisel, D. D., and Zhou, Q. H., The micrometeoroid mass flux into the upper atmosphere:Arecibo results and a comparison with prior estimates, Geophys. Res. Lett.,2001,28,1929-1932.
Matsunanmi, A., Yamamura, Y., Itikawa, Y., Itoh, N., Kazumata, Y, Miyagawa, S., Morita, K., and Shimizu, R., A semiempirical formula for the energy dependence of the sputtering yield, Radiat. Eff. Lett,1980,57,15-21.
McKinley, D. W. R., and Millman, P. M., A phenomenological theory of radar echoes from meteors, Proc. Inst. Radio Engrs.,1949,37,364-375.
McNaught, R. H., and Asher, D. J., Leonid dust trails and meteor storms, WGN,1999, 27,85-102.
Mendis, D. A., Wong, Wai-Ho, Rosenberg, M., and Sorasio, G., Micrometeoroid flight in the upper atmosphere:Electron emission and charging, J. Atmos. Solar Terr. Phys.,2005,67,1178-1189.
Meteorite.fr, http://www.meteorite.fr.
Murad, E., and Roth, C., Evaporation of high speed sporadic meteors, Atmos. Chem. Phys.,2004,4,737-740.
Opik, E. J., Physics of Meteor Flight in the Atmosphere, Interscience Pub., New York, 1958,61,56,62.
Pellinen-Wannberg, A., and Wannberg, G., Meteor observations with the European incoherent scatter UHF radar, J. Geophys. Res.,1994,99,11379-11390.
Plane, J. M. C., A time-resolved model of the mesospheric Na layer:constraints on the meteor input function, Atmos. Chem. Phys.,2004,4,627-638.
Plane, J. M. C., Atmospheric chemistry of meteoric metals, Chemical Reviews,2003, 103(12),4963-4984.
Plane, J. M. C., Cox, R. M., Qian, J., Pfenninger, W. M., Papen, G. C., Gardner, C. S., and Espy P. J., Mesospheric Na layer at extreme high latitudes in summer, J. Geophys. Res.,1998,103,6381-6389.
Plane, J. M. C., Gardner, C. S., Yu, J., She, C. Y, Garcia, R. R., and Pumphrey, H. C., Mesospheric Na layer at 40°N:Modeling and observations, J. Geophys. Res.,1999, 104,D3,3773-3788.
Plane, J. M. C., Murray, B. J., Chu, X., and Gardner, C. S., Removal of meteoric iron on polar mesospheric clouds, Science,2004,304,426-428, doi:10.1126/science.1093236.
Qian, J., Gu, Y, and Gardner, C. S., Characteristics of the sporadic Na layers observed during the Airborne Lidar and Observations of Hawaiian Airglow/Airborne Noctilucent Cloud (ALOHA/ANLC-93) campaigns, Journal of Geophysical Research,1998,103(D6),6333-6347.
Raizada, S., and Tepley, C. A., Seasonal variation of mesospheric iron layers at Arecibo:First results from low-latitudes, Geophys. Res. Lett.,2003,30(2),1082, doi:10.1029/2002GL016537.
Rogers, L. A., Hill, K. A., and Hawkes, R. L., Mass loss due to sputtering and thermal processes in meteoroid ablation, Planetary and Space Science,2004,53(13), 1341-1354.
Simonich, D. M., Clemesha, B. R., and Kirchhoff, V. W. J. H., The mesospheric sodium layer at 23°S:Nocturnal and seasonal variations, J. Geophys. Res.,1979, 84,1543-1550.
Slipher, V. M., Emission in the spectrum of the light of the night sky, Publ. Astron. Soc. Pac.,1929,41,262-263.
Sodha, M. S., Journal of Applied Physics,1961,32,2059.
Sorasio, G., Mendis, D. A., and Rosenberg, M., The role of thermionic emission in meteor physics, Planetary and Space Science,2001,49,1257-1264.
Sputtering by Ion Bombardment, Berlin, NewYork, Springer-Verlag,1981-c1991.
States, R. J., and C. S. Gardner, Structure of the mesospheric Na layer at 40°N latitude: Seasonal and diurnal variations, J. Geophys. Res.,1999,104,11,783-11,798.
Sykes, M. V., Walker, R. G., Cometary dust trails. I. Survey. Icarus,1992,95, 180-210.
Taylor, A. D., and Elford, W. G., Meteoroid orbital element distributions at 1 AU deduced from the Harvard Radio Meteor Project observations, Earth, Planets and Space,1998,50,569-575.
Taylor, A. D., Radiant distribution of meteoroids encountering the Earth, Adv. Space Res.,1997,20(8),1505-1508.
The American Meteor Society, Geneseo NY, http://www.amsmeteors.org.
Visual Meteor Database (VMDB)_International Meteor Organization, http://www.imo.net/data.
von Zahn, U., von der Gathen, P., and Hansen, G., Forced release of sodium from upper atmosphere dust particles, Geophys. Res. Lett.,1987,14,76-79.
von Zahn, U., and Hansen, T. L., Sudden neutral sodium layers:a strong link to sporadic-E layers, J. Atoms. Terr. Phys.,1988,50,93-104.
Wasson, J. T., and Kyte, F. T., On the Influx of Small Comets into the Earths Atmosphere,2. Interpretation-Comment, Geophys. Res. Lett.,1987,14, 779-780.
Weinek, L., Astronomische Beobachtungen an der K.K. Sternwarte zu Prag, in den Jahren 1885,1886, und 1887,1886.
Whipple, E. C., Report on Progress in Physics,1981,44,1197.
Williams, I. P., The velocity of meteoroids:a historical review, Atmos. Chem. Phys., 2004,4,471-475.
Williams, I. P., and Murad, E., Meteors in the Earth's Atmosphere, edited by E. Murad and I. P. Williams, Cambridge Univ. Press, New York,2002.
Yi, F., Zhang, S. D., Zeng, H. J., He, Y. J., Yue, X. C., Liu, J. B., Lv, H. F., and Xiong, D. H., Lidar observations of sporadic Na layers over Wuhan (30.5°N,114.4°N), Geophys. Res. Lett.,2002,29(9),1345, doi:10.1029/2001GL014353.
Yi, F., Zhang, S., Yu, C., He, Y, Yue, X., Huang, C., Zhou, J., Simultaneous observations of sporadic Fe and Na layers by two closely colocated resonance fluorescence lidars at Wuhan (30.5°N,114.4°E), China, Journal of Geophysical Research,2007,112, D04303, doi:10.1029/2006JD007413.
Yi, F., Zhang, S., Yu, C., He, Y, Yue, X., Huang, C., and Li, W., Some ubiquitous features of the mesospheric Fe and Na layer borders from simultaneous and common-volume Fe and Na lidar observations, J. Geophys. Res.,2008,113, A04S91, doi:10.1029/2007JA012632.
Yi, F., Yu, C., Zhang, S., Yue, X., He, Y, Huang, C., Zhang, Y, and Huang, K., Seasonal variations of the nocturnal mesospheric Na and Fe layers at 30°N, J. Geophys. Res.,2009,114, D01301, doi:10.1029/2008JD010344.
Zhou, Q., Tepley, C. A., and Sulzer, M. P., Meteor observations by the Arecebo
430MHz incoherent scatter radar I:results from time-integrated observations, J. Atmos. Terr. Phys.,1995,57,421-431.
Alpers, M., Hoffner, J., and von Zahn, U., Upper atmosphere Ca and Ca+at mid-latitudes:First simultaneous and common-volume lidar observations, Geophys. Res. Lett.,1996,23,567-570.
Anderson, H. H., and Bay, H. L., Sputtering Yield Measurments. In:Behrisch, R. (Ed.), Sputtering by Particle Bombardment, Springer-Verlag, Berlin,1981.
Appleton, E. V., and Naismith, R., Radio detection of Meteor trails and allied phenomena, Proc. Roy. Soc.,1947, A59,461-472.
Argall, P. S., and Sica, R. J., A comparison of Rayleigh and sodium lidar temperature climatologies, Ann. Geophys.,2007,25(1),27-35.
Asher, D. J., Leonid dust trail theories, Proc. International Meteor Conference, Frasso Sabino (ed. Arlt, R.),1999.
Asher, D. J., Bailey, M. E., and Emel'Yanenko, V. V., Resonant meteoroids from Comet Tempel-Tuttle in 1333:the cause of the unexpected Leonid outburst in 1998, Mon. Not. R. Astron. Soc.,1999,304(4), L53-L56.
Baggaley, W. J., Bennett, R. G. T., Steel, D. I., and Taylor, A. D.:Advanced Meteor Orbit Radar:AMOR, Qt. Jl. R. Astr. Soc.,1994,35,293-320.
Baggaley, W. J., Advanced meteor orbit radar observations of interstellar meteoroids, Journal of Geophysical Research,2000,105(A5),10353-10361.
Baggaley, W. J., Radar observations, in Meteors in the Earth's Atmosphere, edited by E. Murad and I. P. Williams, Cambridge Univ. Press, New York,2002,123-148.
Batista, P. P., Clemesha, B. R., Batista, I. S., and Simonich, D. M., Characteristics of the sporadic sodium layers observed at 23 degree S, Journal of Geophysical Research,1989,94,15349-14358.
Batista, P. P., Clemesha, B. R., and Simonich, D. M., Horizontal structures in sporadic sodium layers at 23 degrees south, Geophysical Research Letters,1991,18, 1027-1030.
Benzenberg, J. F., and Brandes, H. W., Versuch die Entfernung, die Geschwindigkeit und die Bahn der Sternschnuppen zu bestimmen, Annalen der Phys.,1800,6, 224-232.
Bernard, R., The identification and the origin of atmospheric sodium, Astrophysical Journal,1939,89,133-135.
Bohdansky, J., A universal relation for the sputtering yield of monoatomic solids at normal incidence, J. Nucl. Instr. Met. Phys. Res. B.,1984,2,587-591.
Bohdansky, J., Yield data for Tokamaks-A comparison of measurments and estimates, J. Nucl. Mater.,1980,93-94,44-60.
Borovicka, J., Elemental Abundances in Leonid and Perseid Meteoroids, Earth, Moon, and Planets,2005, Volume 95, Numbers 1-4,245-253(9).
Borovicka, J., Two components in meteor spectra, Planet. Space Sci., February 1994, 42(2),145-150.
Bowman, M. R., Gibson, A. J., and Sandford, M. C., Atmospheric Sodium Measured by a Tuned Laser Radar, Nature,1969,221,456-458.
Bronshten, V. A., Physics of Meteoric Phenomena, D. Reidel Pub. Co., Dordrecht, 1983,91,265.
Brown, P., and Jones, J., A determination of the strengths of the sporadic radio-meteor sources, Earth, Moon and Planets,1995,68,223-245.
Ceplecha, Z., Borovicka, J., Elford, W.G., ReVelle, D.O., Hawkes, R.L., Porubcan, V., and Simek, M., Meteor phenomena and bodies, Space Sci. Rev.,1998,84, 327-471.
Chu, X., Liu, A. Z., Papen, G., Gardner, C. S., Kelley, M., Drummond, J., and Fugate, R., Lidar observations of elevated temperatures in bright chemiluminescent meteor trails during the 1998 Leonid Shower, Geophysical Research Letters,2000,27(13), 1815-1818.
Chu, X., Pan, W., Papen, G., Gardner, C. S., Swenson, G., and Jenniskens, P., Characteristics of Fe ablation trails observed during the 1998 Leonid meteor shower, Geophysical Research Letters,2000,27(13),1807-1810.
Clemesha, B. R., Kirchhoff, V. W. J. H., Simonich, D. M., and Takahashi, H., Evidence of an extra-terrestrial source for mesospheric sodium layer, Geophys. Res. Lett.,1978,5,873-876.
Clemesha, B. R., Batista, P. P., and Simonich, D. M., Concerning the origin of enhanced sodium layers, Geophys. Res. Lett.,1988,15(11),1267-1270.
Clemesha, B. R., Sporadic neutral metal layers in the mesosphere and lower thermosphere, J. Atmos. Terr. Phys.,1995,57(7),725-736.
Clemesha, B. R., Batista P. P., and Simonich, D. M., An evalution of the evidence for ion recombination as a source of sporadic neutral layers in the lower thermosphere, Adv. Space Res.,1999,24,541-556.
Collins, R. L., Hallinan, T. J., Smith, R. W., and Hernandez, G., Lidar observations of a large high-altitude sporadic Na layer during active aurora, Geophysical Research Letters,1996,23(24),3655-3658.
Cziczo, D. J., Thomson, D. S., and Murphy, D. M., Ablation, flux, and atmospheric implications of meteors inferred from stratospheric aerosol, Science,2001,291, 1772-1775.
Dyrud, L. P., Oppenheim, M. M., and vorn Endt, A. F., The anomalous diffusion of meteor trails, Geophysical Research Letters,2001,28(14),2775-2778.
Elkin, W. L., The Velocity of Meteors as Deduced from Photographs at the Yale Observatory, Ap. J.,1900,12,4-7.
Ellyett, C. D., and Davies, J. G., Velocities of meteor measured by Diffraction of Radio Waves from Trails during formation, Nature,1948,161,596-597.
Ellyett, C. D., The daytime meteor streams of 1949:measurement of velocities, Mon. Not. R. Astr. Soc.,1949,109,359-364.
Fan, Z. Y., Plane, J. M. C., Gumbel, J., Stegman, J., and Llewellyn, E. J., Satellite measurements of the global mesospheric sodium layer, Atmos. Chem. Phys.,2007, 7,4107-4115.
Friedman, J. S., Gonzalez, S. A., Tepley, C. A., Zhou, Q., and Sulzer, M. P., Simultaneous atomic and ion layer enhancements observed in the mesopause region during the Coqui Ⅱ sounding rocket campaign, Geophys. Res. Lett.,2000, 27(4),449-452.
Galligan, D. P., and Baggaley, W. J., The radiant distribution of AMOR radar meteors, Mon. Not. R. Astron. Soc.,2005,359(2),551-560.
Gardner, C. S., Plane, J. M. C., Pan, W., Vondra, T., Murray, B. J., and Chu, X., Seasonal variations of the Na and Fe layers at the South Pole and their implications for the chemistry and general circulation of the polar mesosphere, Journal of Geophysical Research,2005,110, D10302, doi:10.1029/2004JD005670.
Gerding, M., Alpers, M., Hoffner, J., and von Zahn, U., Sporadic Ca and Ca+layers at mid-latitudes:Simultaneous observations and implications for their formation, Annales Geophysicae,2001,19,47-58.
Gerding, M., Alpers, M., Hoffner, J., and von Zahn, U., Simultaneous K and Ca lidar observations during a meteor shower on March 6-7,1997, at Kuhlungsborn, Germany, Journal of Geophysical Research,1999,104(A11),24689-24698.
Gibson, A. J., and Sandford, M. C. W., The seasonal variation of the night-time sodium layer, Journal of Atmospheric and Terrestrial Physics,1971,33, 1675-1684.
Gong, S. S., Yang, G. T., Wang, J. M., Cheng, X. W., Li, F. Q., and Wan, W. X., A double sodium layer event observed over Wuhan, China by lidar, Geophysical Research Letters,2003,30(5),1209-1212, doi:10.1029/2002GL016135.
Hoffner, J., Friedman, J.S., The mesospheric metal layer topside:a possible connection to meteoroids. Atmospheric Chemistry and Physics,2004,4,801-808.
Hoffner, J., Friedman, J.S., The mesospheric metal layer topside:Examples of simultaneous metal observations. Journal of Atmospheric and Solar-Terrestrial Physics,2005,67,1226-1237.
Hansen, G., and von Zahn, U., Sudden sodium layers in polar latitudes, J. Atmos. Terr. Phys.,1990,52,585-608.
Harvey, G. A., Elemental abundance determinations for meteors by spectroscopy, J. Geophys. Res.,1973,78,3913-3926.
Helmer, M., Plane, J. M. C., Qian, J., and Gardner, C. S., A model of meteoric iron in the upper atmosphere, J. Geophys. Res.,1998,103,10913-10926.
Herlofson, N., The theory of meteor ionization, Proc. Phys. Soc.,1946,11,444-445.
Hey, J. S., and Stewart G. S., Derivation of meteor stream radiants by radio reflex methods, Nature,1946,158,481-483.
Hey, J. S., Parsons, S. J., and Stewart, G. S., Radio observations of the Giacobinid Meteor shower,1946, Mon.Not. R. Astr. Soc.,1947,107,176-183.
Hey, J. S., and Stewart, G. S., Radar observations of meteors, Proc. Phys. Soc.,1947, 59,858-883.
Hughes, D. W., Meteors. In, Cosmic Dust, edited by McDonnell, J. A. M., Wiley, London,1978,123-185.
Hughes, D. W., Meteors and cosmic dust, Endeavour,1997,21,31-35.
Hunten, D. M., Turco, R. P., and Toon, O. B., Smoke and dust particles of the meteoric origin in the mesosphere, J. Atmos. Sci.,1980,37,1342-1357.
International Meteor Organization, http://www.imo.net.
Janches, D., Mathews, J. D., Meisel, D., and Zhou, Q., Orbital properties of the Arecebo micrometeorites at Earth intersection, Icarus,2001,150,206-218.
Janches, D., Nolan, M. C., Meisel, D. D., Mathews, J. D., Zhou, Q. H., and Moser, D. E., On the geocentric micrometeor velocity distribution, J. Geophys. Res.,2003, 108(A6),1222, doi:10.1029/2002JA009789.
Janches, D., and Chau, J. L., Observed diurnal and seasonal behavior of the micrometeor flux using the Arecibo and Jicamarca radars, J. Atmos. Solar Terr. Phys.,2005,67,1196-1210.
Janches, D., Mathews, J. D., Meisel, D. D., Getman, V. S., Zhou, Q. H., Doppler studies of near-antapex UHF radar micrometeors, Icarus,2000,143,347-353.
Janches, D., Heinselman, C. J., Chau, J. L., Chandran, A., and Woodman, R., Modeling the global micrometeor input function in the upper atmosphere observed by high power and large aperture radars, J. Geophys. Res.,2006,111, A07317, doi:10.1029/2006JA011628.
Jones, W, Monthly Notices of the Royal Astronomical Society,1997,288,995.
Kane, T. J., Hostetler, C. A., and Gardner, C. S., Horizontal and vertical structure of the major sporadic sodium layer events observed during ALOHA-90, Geophysical Research Letters,1991,18(7),1365-1368.
Kane, T. J., Gardner, C. S., Zhou, Q., Mathews, J. D., and Tepley, C. A., Lidar, radar and airglow observations of a prominent sporadic Na/sporadic E layer event at Arecibo during AIDA-89, Journal of Atmospheric and Terrestrial Physics,1993,55, 499-511.
Kresak, L., Meteor storms. In meteoroids and their Parent Bodies, eds Stohl J. and Williams I.P., Slovak Academy of Sciences, Bratislava,1993,147-156.
Liu, Y., and Yi, F., Bahavior of sporadic Na layers on small time scale, J. Atmos. Solar Terr. Phys.,2009,71,1374-1382.
Love, S. G., and Brownlee, D. E., Heating and thermal transformation of micrometeoroids entering the Earth's atmosphere, Icarus,1991,89,26-43.
Lovell, A. C. B., Banwell, C. J., and Clegg, J. A., Radio Echo Observations of the Giacobinid Meteors 1946, Mon. Not. R. Astr. Soc.,1947,107,164-175.
Lynch, K. A., Gelinas, L. J., Kelley, M. C., Collins, R. L., Widholm, M., Rau, D., MacDonald, E., Liu, Y, Ulwick, J., and Mace, P., Multiple sounding rocket observations of charged dust in the polar winter mesosphere, J. Geophys. Res., 2005,110, A03302, doi:10.1029/2004JA010502.
Ma, Y. H., and He, Y. W., The Third peak of the 1998 Leonid Meteor Shower, Chinese Journal of Astronomy and AstroPhysics,2001,1(3),271-274.
Ma, Z., and Yi, F., High-altitude sporadic metal atom layers observed with Na and Fe lidars at 30°N, Journal of Atmospheric and Solar-Terrestrial Physics,2010,72, 482-491.
Mathews, J. D., Zhou, Q., Philbrick, C. R., Morton, Y. T., and Gardner, C. S., Observations of ion and sodium layer coupled processes during AIDA, J. Atmos. Terr. Phys.,1993,55,487-498.
Mathews, J. D., Janches, D., Meisel, D. D., and Zhou, Q. H., The micrometeoroid mass flux into the upper atmosphere:Arecibo results and a comparison with prior estimates, Geophys. Res. Lett.,2001,28,1929-1932.
Matsunanmi, A., Yamamura, Y., Itikawa, Y., Itoh, N., Kazumata, Y, Miyagawa, S., Morita, K., and Shimizu, R., A semiempirical formula for the energy dependence of the sputtering yield, Radiat. Eff. Lett,1980,57,15-21.
McKinley, D. W. R., and Millman, P. M., A phenomenological theory of radar echoes from meteors, Proc. Inst. Radio Engrs.,1949,37,364-375.
McNaught, R. H., and Asher, D. J., Leonid dust trails and meteor storms, WGN,1999, 27,85-102.
Mendis, D. A., Wong, Wai-Ho, Rosenberg, M., and Sorasio, G., Micrometeoroid flight in the upper atmosphere:Electron emission and charging, J. Atmos. Solar Terr. Phys.,2005,67,1178-1189.
Meteorite.fr, http://www.meteorite.fr.
Murad, E., and Roth, C., Evaporation of high speed sporadic meteors, Atmos. Chem. Phys.,2004,4,737-740.
Opik, E. J., Physics of Meteor Flight in the Atmosphere, Interscience Pub., New York, 1958,61,56,62.
Pellinen-Wannberg, A., and Wannberg, G., Meteor observations with the European incoherent scatter UHF radar, J. Geophys. Res.,1994,99,11379-11390.
Plane, J. M. C., A time-resolved model of the mesospheric Na layer:constraints on the meteor input function, Atmos. Chem. Phys.,2004,4,627-638.
Plane, J. M. C., Atmospheric chemistry of meteoric metals, Chemical Reviews,2003, 103(12),4963-4984.
Plane, J. M. C., Cox, R. M., Qian, J., Pfenninger, W. M., Papen, G. C., Gardner, C. S., and Espy P. J., Mesospheric Na layer at extreme high latitudes in summer, J. Geophys. Res.,1998,103,6381-6389.
Plane, J. M. C., Gardner, C. S., Yu, J., She, C. Y, Garcia, R. R., and Pumphrey, H. C., Mesospheric Na layer at 40°N:Modeling and observations, J. Geophys. Res.,1999, 104,D3,3773-3788.
Plane, J. M. C., Murray, B. J., Chu, X., and Gardner, C. S., Removal of meteoric iron on polar mesospheric clouds, Science,2004,304,426-428, doi:10.1126/science.1093236.
Qian, J., Gu, Y, and Gardner, C. S., Characteristics of the sporadic Na layers observed during the Airborne Lidar and Observations of Hawaiian Airglow/Airborne Noctilucent Cloud (ALOHA/ANLC-93) campaigns, Journal of Geophysical Research,1998,103(D6),6333-6347.
Raizada, S., and Tepley, C. A., Seasonal variation of mesospheric iron layers at Arecibo:First results from low-latitudes, Geophys. Res. Lett.,2003,30(2),1082, doi:10.1029/2002GL016537.
Rogers, L. A., Hill, K. A., and Hawkes, R. L., Mass loss due to sputtering and thermal processes in meteoroid ablation, Planetary and Space Science,2004,53(13), 1341-1354.
Simonich, D. M., Clemesha, B. R., and Kirchhoff, V. W. J. H., The mesospheric sodium layer at 23°S:Nocturnal and seasonal variations, J. Geophys. Res.,1979, 84,1543-1550.
Slipher, V. M., Emission in the spectrum of the light of the night sky, Publ. Astron. Soc. Pac.,1929,41,262-263.
Sodha, M. S., Journal of Applied Physics,1961,32,2059.
Sorasio, G., Mendis, D. A., and Rosenberg, M., The role of thermionic emission in meteor physics, Planetary and Space Science,2001,49,1257-1264.
Sputtering by Ion Bombardment, Berlin, NewYork, Springer-Verlag,1981-c1991.
States, R. J., and C. S. Gardner, Structure of the mesospheric Na layer at 40°N latitude: Seasonal and diurnal variations, J. Geophys. Res.,1999,104,11,783-11,798.
Sykes, M. V., Walker, R. G., Cometary dust trails. I. Survey. Icarus,1992,95, 180-210.
Taylor, A. D., and Elford, W. G., Meteoroid orbital element distributions at 1 AU deduced from the Harvard Radio Meteor Project observations, Earth, Planets and Space,1998,50,569-575.
Taylor, A. D., Radiant distribution of meteoroids encountering the Earth, Adv. Space Res.,1997,20(8),1505-1508.
The American Meteor Society, Geneseo NY, http://www.amsmeteors.org.
Visual Meteor Database (VMDB)_International Meteor Organization, http://www.imo.net/data.
von Zahn, U., von der Gathen, P., and Hansen, G., Forced release of sodium from upper atmosphere dust particles, Geophys. Res. Lett.,1987,14,76-79.
von Zahn, U., and Hansen, T. L., Sudden neutral sodium layers:a strong link to sporadic-E layers, J. Atoms. Terr. Phys.,1988,50,93-104.
Wasson, J. T., and Kyte, F. T., On the Influx of Small Comets into the Earths Atmosphere,2. Interpretation-Comment, Geophys. Res. Lett.,1987,14, 779-780.
Weinek, L., Astronomische Beobachtungen an der K.K. Sternwarte zu Prag, in den Jahren 1885,1886, und 1887,1886.
Whipple, E. C., Report on Progress in Physics,1981,44,1197.
Williams, I. P., The velocity of meteoroids:a historical review, Atmos. Chem. Phys., 2004,4,471-475.
Williams, I. P., and Murad, E., Meteors in the Earth's Atmosphere, edited by E. Murad and I. P. Williams, Cambridge Univ. Press, New York,2002.
Yi, F., Zhang, S. D., Zeng, H. J., He, Y. J., Yue, X. C., Liu, J. B., Lv, H. F., and Xiong, D. H., Lidar observations of sporadic Na layers over Wuhan (30.5°N,114.4°N), Geophys. Res. Lett.,2002,29(9),1345, doi:10.1029/2001GL014353.
Yi, F., Zhang, S., Yu, C., He, Y, Yue, X., Huang, C., Zhou, J., Simultaneous observations of sporadic Fe and Na layers by two closely colocated resonance fluorescence lidars at Wuhan (30.5°N,114.4°E), China, Journal of Geophysical Research,2007,112, D04303, doi:10.1029/2006JD007413.
Yi, F., Zhang, S., Yu, C., He, Y, Yue, X., Huang, C., and Li, W., Some ubiquitous features of the mesospheric Fe and Na layer borders from simultaneous and common-volume Fe and Na lidar observations, J. Geophys. Res.,2008,113, A04S91, doi:10.1029/2007JA012632.
Yi, F., Yu, C., Zhang, S., Yue, X., He, Y, Huang, C., Zhang, Y, and Huang, K., Seasonal variations of the nocturnal mesospheric Na and Fe layers at 30°N, J. Geophys. Res.,2009,114, D01301, doi:10.1029/2008JD010344.
Zhou, Q., Tepley, C. A., and Sulzer, M. P., Meteor observations by the Arecebo
430MHz incoherent scatter radar I:results from time-integrated observations, J. Atmos. Terr. Phys.,1995,57,421-431.