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Comparison of Sporadic Sodium Layer Characteristics Observed at Different Time Resolutions : Volume 31, Issue 11 (04/11/2013)

By Liu, Y. J.

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Book Id: WPLBN0004002278
Format Type: PDF Article :
File Size: Pages 14
Reproduction Date: 2015

Title: Comparison of Sporadic Sodium Layer Characteristics Observed at Different Time Resolutions : Volume 31, Issue 11 (04/11/2013)  
Author: Liu, Y. J.
Volume: Vol. 31, Issue 11
Language: English
Subject: Science, Annales, Geophysicae
Collections: Periodicals: Journal and Magazine Collection (Contemporary), Copernicus GmbH
Historic
Publication Date:
2013
Publisher: Copernicus Gmbh, Göttingen, Germany
Member Page: Copernicus Publications

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Wang, J. H., Cheng, X. W., Clemesha, B. R., & Liu, Y. J. (2013). Comparison of Sporadic Sodium Layer Characteristics Observed at Different Time Resolutions : Volume 31, Issue 11 (04/11/2013). Retrieved from http://www.ebooklibrary.org/


Description
Description: Instituto Nacional de Pesquisas Espaciais Avenida dos Astronautas, 1758, 12227-010 São Jose dos Campos, Brazil. Sporadic sodium (Nas) layers, occurring in roughly the same height range as ionospheric sporadic-E layers, were first detected by lidar some 30 yr ago. Nas layers have a typical thickness of a few hundred meters to a few km, with peak atom concentrations several times that of the background layer. Despite a great deal of excellent work over the past decades, the source of Nas layers is still not altogether clear, partly as a result of our incomplete knowledge of Nas layer characteristics. In this paper we concentrate on some typical case studies chosen from the ~127 h of sporadic sodium layer observations made at a time resolution of 1.5 s at Yanqing (115.97° E, 40.47° N), Beijing, China. This is a much better time resolution than what has been employed in most earlier measurements. The results show that the Nas layer peak heights are dispersed at slightly different although adjacent heights. When averaged over several minutes, as has been the case with most earlier measurements, the height scatter results in an apparent layer thickness of a few km. We conclude, therefore, that these dispersed peaks at different but adjacent heights constitute the 5 min Nas layer. Similar to the observations of sporadic-E-ion (Es) layers and meteor rate, we observe quasi-periodic fluctuations on a timescale on the order of several minutes in the peak height and the peak density of sporadic layers, which is a universal feature but concealed by the lower temporal resolution previously adopted. Spatially localized multiple scatterers and multiple thin layers with similar apparent movement in Nas layers are also found. We discuss the possible formation mechanism by the direct deposition of large swarms of micrometeoroids and demonstrate a typical example of meteor trails evolving into a Nas layer, which suggests that this mechanism might indeed occur.

Summary
Comparison of sporadic sodium layer characteristics observed at different time resolutions

Excerpt
Batista, P. P., Clemesha, B. R., Batista, I. S., and Simonich, D. M.: Characteristics of the Sporadic Sodium Layers Observed at 23° S, J. Geophys. Res., 94, 15349–15358, 1989.; Batista, P. P., Clemesha, B. R., and Simonich, D. M.: Horizontal structure in sporadic sodium layers at 23° S, Geophys. Res. Lett., 18, 1027–1030, 1991.; Beatty, T. J., Collins, R. L., Gardner, C. S., Hostetler, C. A., SechristJr., C. F., and Tepley, C. A.: Simultaneous radar and lidar observations of sporadic E and Na layers at Arecibo, Geophys. Res. Lett., 16, 1019–1022, 1989.; Briczinski, S. J., Mathews, J. D., and Meisel, D. D.: Statistical and fragmentation properties of the micrometeoroid flux observed at Arecibo, J. Geophys. Res.-Space, 114, A04311, doi:10.1029/2009JA014054, 2009.; Ceplecha, Z. V. E. K., Borovi, V. C., Ka, J. V. R. I., Elford, W. G., ReVelle, D. O., Hawkes, R. L., Porub, V. C., An, V. I. R., and Imek, M. V. S.: Meteor phenomena and bodies, Space Sci. Rev., 84, 327–471, 1998.; Clemesha, B. R.: Sporadic neutral metal layers in the mesosphere and lower thermosphere, J. Atmos. Terr. Phys., 57, 725–736, 1995.; Clemesha, B. R.: A review of recent MLT studies at low latitudes, Ann. Geophys., 22, 3261–3275, doi:10.5194/angeo-22-3261-2004, 2004.; Clemesha, B. R., Kirchhoff, V. W. J. H., Simonich, D. M., and Takahashi, H.: Evidence of an extraterrestrial source for the mesospheric sodium layer, Geophys. Res. Lett., 5, 873–876, 1978.; Clemesha, B. R., Batista, P. P., and Simonich, D. M.: Concerning the origin of enhanced sodium layers, Geophys. Res. Lett., 15, 1267–1270, 1988.; Clemesha, B. R., Batista, P. P., and Simonich, D. M.: Wave-associated sporadic neutral layers in the upper atmosphere, Revista Brasileira de Geofísica, 15, 237–250, 1997.; Clemesha, B. R., Batista, P. P., and Simonich, D. M.: An Evaluation of the Evidence for Ion Recombination as a Source of Sporadic Neutral Layers in the Lower Thermosphere, Adv. Space Res., 24, 547–556, 1999.; Clemesha, B. R., Batista, P. P., Simonich, D. M., and Batista, I. S.: Sporadic structures in the atmospheric sodium layer, J. Geophys. Res., 109, D11306, doi:10.1029/2003JD004496, 2004.; Cox, R. M. and Plane, J. M. C.: An ion-molecule mechanism for the formation of neutral sporadic Na layers, J. Geophys. Res., 103, 6349–6359, 1998.; Cox, R. M., Plane, J. M. C., and Green, J. S. A.: A modeling investigation of sudden sodium layers, Geophys. Res. Lett., 2841–2844, 1993.; Dou, X. K., Xue, X. H., Li, T., Chen, T. D., Chen, C., and Qiu, S. C.: Possible relations between meteors, enhanced electron density layers, and sporadic sodium layers, J. Geophys. Res.-Space, 115, A06311, doi:10.1029/2009JA014575, 2010.; Gardner, C. S.: Sodium Resonance Fluorescence Lidar Applications in Atmospheric Science and Astronomy, Proc. IEEE, 77, 408–418, 1989.; Dyrud, L. P., Urbina, J., Fentzke, J. T., Hibbit, E., and Hinrichs, J.: Global variation of meteor trail plasma turbulence, Ann. Geophys., 29, 2277–2286, doi:10.5194/angeo-29-2277-2011, 2011.; Gardner, C. S., Kane, T. J., Hecht, J. H., Walterscheid, R. L., Yee, J. H., Niciejewski, R. J., Lowe, R. P., and Turnbull, D. N.: Formation Characteristics of Sporadic Na Layers Observed Simultaneously by Lidar and Airglow Instruments During ALOHA-90, Geophys. Res. Lett., 18, 1369–1372, 1991.; Gardner, C. S., Kane, T. J., Senft, D. C., Qian, J., and Papen, G. C.: Simultaneous Observations of Sporadic E, Na, Fe, and Ca+ Layers at Urbana, Illinois: Three Case Studies, J. Geophys. Res., 98, 16865–16873, 1993.; 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 Kuh


 

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