Chu, X., J. S. Friedman, P. Farias Gutierrez, X. Zhang, J. M. Forbes, and H. Liu, AGU Spring Meeting Abstracts, in , p. B1, 2007.

Chu, X., W. Huang, J. S. Friedman, and A. T. Brown, CRRL/CTC: Doppler-free saturation-absorption and polarization spectroscopy for resonance fluorescence Doppler lidars, in Proceedings of the 24 $^{th}$ International Laser Radar Conference, vol. II, edited by Organizing Committee of the 24 $^{th}$ International Laser Radar Conference, p. 809, International Laser Radar Conference, ILRC, 2008a.

Chu et al.(2008b)

Chu, X., W. Huang, J. S. Friedman, and J. P. Thayer, MRI: mobile Fe-resonance/Rayleigh/Mie Doppler lidar principle, design, and analysis, in Proceedings of the 24 $^{th}$ International Laser Radar Conference, vol. II, edited by Organizing Committee of the 24 $^{th}$ International Laser Radar Conference, p. 801, International Laser Radar Conference, ILRC, 2008b.

Chu et al.(2008c)

Chu, X., W. Huang, J. S. Friedman, J. P. Thayer, A. T. Brown, J. Wiig, J. A. Smith, M. Hayman, and B. P. Williams, AGU Fall Meeting Abstracts, in , p. F254, 2008c.

Collins et al.(2002)

Collins, S. C., J. M. C. Plane, M. C. Kelley, T. G. Wright, P. Soldán, T. J. Kane, A. J. Gerrard, B. W. Grime, R. J. Rollason, J. S. Friedman, S. A. González, Q. Zhou, M. P. Sulzer, and C. A. Tepley, A study of the role of ion-molecule chemistry in the formation of sporadic sodium layers, J. Atmos. Sol. Terr. Phys., 64, 845-860, 2002.

Delgado et al.(2005)

Delgado, R., S. Raizada, C. A. Tepley, B. R. Weiner, and J. S. Friedman, AGU Fall Meeting Abstracts, in , p. A237, 2005.

Delgado et al.(2006)

Delgado, R., S. Raizada, C. Tepley, B. R. Weiner, and J. S. Friedman, AGU Spring Meeting Abstracts, in , p. B7, 2006.

Delgado et al.(2006)

Delgado, R., B. R. Weiner, and J. S. Friedman, Chemical model for mid-summer lidar observations of mesospheric potassium over the Arecibo Observatory, Geophys. Res. Lett., 33, L02,801, doi: rm10.1029/2005GL024326, 2006.

Delgado et al.(2012)

Delgado, R., J. S. Friedman, J. T. Fentzke, S. Raizada, and C. A. Tepley, Sporadic metal atom and ion layers and their connection to chemistry and thermal structure in the mesopause region at Arecibo, J. Atmos. Solar-Terr. Phys., 74, 11-23, doi: rm10.1016/j.jastp.2011.09.004, 2012.

Friedman(2003)

Friedman, J. S., Tropical mesopause climatology over the Arecibo Observatory, Geophys. Res. Letters, 30(12), 1642, doi: rm10.1029/2003GL016966, 2003.

Friedman(2006)

Friedman, J. S., The Arecibo potassium lidar daylight receiver, in 23rd International Laser Radar Conference, edited by C. Nagasawa and N. Sugimoto, pp. 557-560, ILRC, 2006.

Friedman and Chu(2005)

Friedman, J. S., and X. Chu, AGU Fall Meeting Abstracts, in , p. A1155, 2005.

Friedman and Chu(2006a)

Friedman, J. S., and X. Chu, 36th COSPAR Scientific Assembly, in , COSPAR Meeting, vol. 36, p. 3308, 2006a.

Friedman and Chu(2006b)

Friedman, J. S., and X. Chu, Tropical/sub-tropical mesopause thermal structure from Arecibo, PR (18.35 $^{\circ}$ N, 66.75 $^{\circ}$ W) and Maui, HI (20.7 $^{\circ}$ N, 156.3 $^{\circ}$ W), in 23rd International Laser Radar Conference, edited by C. Nagasawa and N. Sugimoto, pp. 577-580, ILRC, 2006b.

Friedman and Chu(2007)

Friedman, J. S., and X. Chu, Nocturnal temperature structure in the mesopause region over the Arecibo Observatory (18.35 $^\circ$ N, 66.75 $^\circ$ W): Seasonal variations, J. Geophys. Res., 112, D14,107, doi: rm10.1029/2006JD008220, 2007.

Friedman and Janches(2005)

Friedman, J. S., and D. Janches, Special issue on meteors and the mesopause, J. Atmos. Sol. Terr. Phys., 67, 1157-1158, doi: rm10.1016/j.jastp.2005.06.001, 2005.

Friedman and She(1993)

Friedman, J. S., and C. Y. She, The effects of molecular geometry on the depolarized stimulated gain spectra of simple liquids, J. Chem. Phys., 99(7), 4960-4969, doi: rm10.1063/1.466023, 1993.

Friedman et al.(1991a)

Friedman, J. S., B. L. Bracewell, H. D. Hochheimer, and C. Y. She, Stimulated Brillouin Gain Spectroscopy at High Pressure, in Frontiers of High Pressure Research, NATO ASI Series B, vol. 286, edited by H. D. Hochheimer and R. D. Etters, p. 209, NATO, Plenum Press, 1991a.

Friedman et al.(1991b)

Friedman, J. S., M. C. Lee, and C. Y. She, Depolarized stimulated gain spectra of liquid CS

and benzene at room temperature, Chem. Phys. Lett., 186(2,3), 161-169, doi: rm10.1016/S0009-2614(91)85123-E, 1991b.

Friedman et al.(1997)

Friedman, J. S., C. A. Tepley, P. A. Castleberg, and H. Roe, Middle-atmospheric Doppler lidar using an iodine-vapor edge filter, Opt. Letters, 22, 1648-1650, 1997.

Friedman et al.(2000)

Friedman, J. S., S. A. González, C. A. Tepley, Q. Zhou, M. P. Sulzer, S. C. Collins, and B. W. Grime, Simultaneous atomic and ion layer enhancements observed in the mesopause region over Arecibo during the Coqui II sounding rocket campaign, Geophys. Res. Letters, 27, 449-452, 2000.

Friedman et al.(2001)

Friedman, J. S., C. A. Tepley, Q. Zhou, and R. Delgado, American Geophysical Union, Fall Meeting 2001, abstract #SA52A-09, in , pp. A09-+, 2001.

Friedman et al.(2002)

Friedman, J. S., S. C. Collins, R. Delgado, and P. A. Castleberg, Mesospheric potassium layer over the Arecibo Observatory, $18.3^\circ$ N, $66.75^\circ$ W, Geophys. Res. Lett., 29(5), 1071, doi: rm10.1029/2001GL013542, 2002.

Friedman et al.(2002)

Friedman, J. S., Q. H. Zhou, C. A. Tepley, S. Raizada, and M. P. Sulzer, American Geophysical Union, Fall Meeting 2002, abstract #SA62B-0402, in , 2002.

Friedman et al.(2003)

Friedman, J. S., C. A. Tepley, S. Raizada, Q. H. Zhou, J. Hedin, and R. Delgado, Potassium Doppler-resonance lidar for the study of the mesosphere and lower thermosphere at the Arecibo Observatory, J. Atmos. Sol. Terr. Phys., 65(16-18), 1411-1424, doi: rm10.1016/S1364-6826(03)00205-0, 2003.

Friedman et al.(2007)

Friedman, J. S., P. Farias-Gutierrez, X. Chu, J. Forbes, X. Zhang, and J. Xu, AGU Fall Meeting Abstracts, in , p. A287, 2007.

Friedman et al.(2008)

Friedman, J. S., I. González, and W. Huang, Faraday filter: A comparison between hot and cold cell design, in Proceedings of the 24 $^{th}$ International Laser Radar Conference, vol. II, edited by Organizing Committee of the 24 $^{th}$ International Laser Radar Conference, p. 835, International Laser Radar Conference, ILRC, 2008.

Friedman et al.(2009a)

Friedman, J. S., J. T. Fentzke, R. Delgado, S. Raizada, Q. Zhou, and C. A. Tepley, AGU Fall Meeting Abstracts, in , p. B1454, 2009a.

Friedman et al.(2009b)

Friedman, J. S., X. Zhang, X. Chu, and J. M. Forbes, Longitudinal variations of the solar semidiurnal tides in the mesosphere and lower thermosphere at low latitudes observed from ground and space, J. Geophys. Res., 114, D11,114, doi: rm10.1029/2009JD011763, 2009b.

Friedman et al.(2010)

Friedman, J. S., X. Zhang, X. Chu, and J. M. Forbes, Low-latitude thermal semidiurnal tide: Longitudinal and seasonal variations based on ground-based measurements from Arecibo and Maui, in Proceedings of the SPIE: Remote Sensing of Clouds and the Atmosphere, vol. 7827, edited by R. H. Picard, K. Schäfer, A. Comeron, and M. van Weele, SPIE, 2010.

Friedman et al.(2011)

Friedman, J. S., X. Chu, C. G. M. Brum, S. M. Smith, and J. Yue, AGU Fall Meeting Abstracts, in , vol. 1, pp. SA41C-03, 2011.

Friedman et al.(2012)

Friedman, J. S., D. Maldonado-Nieves, I. González, J. Lautenbach, X. Chu, J. A. Smith, and W. Huang, High spectral resolution test and calibration of an ultra-narrowband Faraday anomalous dispersion optical filter for use in daytime mesospheric resonance Doppler lidar, J. Atmos. Solar-Terr. Phys., 80, 187-194, doi: rm10.1016/j.jastp.2012.01.017, 2012.

Friedman et al.(2013)

Friedman, J. S., X. Chu, C. Brum, and X. Lu, Observation of a thermospheric descending layer of neutral K over Arecibo, J. Atmos. Solar-Terr. Phys., doi: rm10.1016/j.jastp.2013.03.002, 2013.

Gelinas et al.(1998)

Gelinas, L. J., K. A. Lynch, M. C. Kelley, S. C. Collins, S. Baker, Q. Zhou, and J. S. Friedman, First observation of meteoric charged dust in the tropical mesosphere, Geophys. Res. Letters, 25, 4047-4050, 1998.

Grime et al.(1999)

Grime, B. W., T. J. Kane, S. C. Collins, M. C. Kelley, C. A. Kruschwitz, J. S. Friedman, and C. A. Tepley, Meteor trail advection and dispersion: Preliminary lidar observations, Geophys. Res. Letters, 26, 675-678, 1999.

Höffner and Friedman(2004)

Höffner, J., and J. S. Friedman, The mesospheric metal layer topside: a possible connection to meteoroids, Atmos. Chem. Phys., 4, 801-808, 2004.

Höffner and Friedman(2005)

Höffner, J., and J. S. Friedman, The mesospheric metal layer topside: Examples of simultaneous metal observations, J. Atmos. Sol. Terr. Phys., 67, 1226-1237, doi: rm10.1016/j.jastp.2005.06.010, 2005.

Huang et al.(2009)

Huang, W., X. Chu, J. Wiig, B. Tan, T. Yamashita, C. Yuan, J. Yue, S. D. Harrell, C. Y. She, B. P. Williams, J. S. Friedman, and R. M. Hardesty, First field demonstration of simultaneous wind and temperature measurements from 5 to 50 km with a Na double-edge magneto-optic filter in a multi-frequency Doppler lidar, Opt. Lett., 34(10), 1552-1554, 2009.

Huang et al.(2013)

Huang, W., X. Chu, Z. Wang, W. Fong, J. A. Smith, B. R. Roberts, and J. S. Friedman, Simultaneous and common-volume lidar observations of the Fe and Na layers in the mesosphere and lower thermosphere at Boulder (40 $^\circ$ N, 105 $^\circ$ W), Colorado, J. Atmos. Solar-Terr. Phys., under review, 2013.

Isham et al.(2000)

Isham, B., C. A. Tepley, M. P. Sulzer, Q. H. Zhou, M. C. Kelley, J. S. Friedman, and S. A. González, Upper atmospheric observations at the Arecibo Observatory: Examples obtained using new capabilities, J. Geophys. Res., 105, 18,609-18,637, 2000.

Kerr et al.(2001a)

Kerr, R. B., R. Garcia, X. He, J. Noto, R. S. Lancaster, C. A. Tepley, S. A. González, J. Friedman, R. A. Doe, M. Lappen, and B. McCormack, Secular variability of the geocoronal Balmer-alpha brightness: magnetic activity and possible human influences, J. Geophys. Res., 106, 28,819-28,830, doi: rm10.1029/1999JA900187, 2001a.

Kerr et al.(2001b)

Kerr, R. B., R. Garcia, X. He, J. Noto, R. S. Lancaster, C. A. Tepley, S. A. González, J. Friedman, R. A. Doe, M. Lappen, and B. McCormack, Periodic variations of geocoronal Balmer-alpha brightness due to solar-driven exospheric abundance variations, J. Geophys. Res., 106, 28,797-28,818, doi: rm10.1029/1999JA900186, 2001b.

Larsen et al.(2003)

Larsen, M., A. Liu, C. Gardner, M. Kelley, S. Collins, J. Friedman, and J. Hecht, Observations of overturning in the upper mesosphere and lower thermosphere and the implications for enhanced winds, EGS - AGU - EUG Joint Assembly, Abstracts from the meeting held in Nice, France, 6 - 11 April 2003, abstract #11511, pp. 11,511-+, 2003.

Larsen et al.(2004)

Larsen, M. F., A. Z. Liu, C. S. Gardner, M. C. Kelley, S. Collins, J. Friedman, and J. H. Hecht, Observations of overturning in the upper mesosphere and lower thermosphere, J. Geophys. Res., 109(D18), D02S04, doi: rm10.1029/2002JD003067, 2004.

Larsen et al.(2007)

Larsen, M. F., D. L. Hysell, Q. H. Zhou, S. M. Smith, J. Friedman, and R. L. Bishop, Imaging coherent scatter radar, incoherent scatter radar, and optical observations of quasiperiodic structures associated with sporadic

layers, J. Geophys. Res., 112(A11), 6321-+, doi: rm10.1029/2006JA012051, 2007.

Noto et al.(2006)

Noto, J., R. B. Kerr, M. A. Migliozzi, C. A. Tepley, J. Friedman, R. Garcia, E. Robles, and L. S. Waldrop, AGU Spring Meeting Abstracts, in , p. A2, 2006.

Raizada et al.(2004a)

Raizada, S., C. A. Tepley, J. Friedman, N. Aponte, S. Gonzalez, and M. Sulzer, AGU Fall Meeting Abstracts, in , p. A1111, 2004a.

Raizada et al.(2004b)

Raizada, S., C. A. Tepley, D. Janches, J. S. Friedman, Q. Zhou, and J. D. Mathews, Lidar observations of Ca and K metallic layers from Arecibo and comparison with micrometeor sporadic activity, J. Atmos. Sol. Terr. Phys., 66, 595-606, doi: rm10.1016/j.jastp.2004.01.030, 2004b.

Raizada et al.(2005)

Raizada, S., C. Tepley, J. Friedman, M. Sulzer, S. Gonzalez, and N. Aponte, AGU Fall Meeting Abstracts, in , p. A236, 2005.

Raizada et al.(2008)

Raizada, S., X. Chu, J. Xu, C. A. Tepley, J. S. Friedman, M. Ejiri, T. Nakamura, and T. Kawahara, AGU Fall Meeting Abstracts, in , pp. A1554+, 2008.

Raizada et al.(2012)

Raizada, S., B. Williams, J. Friedman, S. Sarkhel, C. Tepley, Q. Zhou, and N. Aponte, 39th COSPAR Scientific Assembly, in , COSPAR Meeting, vol. 39, p. 1557, 2012.

Seker et al.(2007)

Seker, I., J. D. Mathews, J. Wiig, P. F. Gutierrez, J. S. Friedman, and C. A. Tepley, First results from the Penn State Allsky Imager at the Arecibo Observatory, Earth, Planets and Space, 59(3), 165-176, 2007.

Smith et al.(2004)

Smith, S. M., J. Friedman, S. Raizada, C. Tepley, J. Baumgardner, and M. Mendillo, AGU Spring Meeting Abstracts, in , p. A1, 2004.

Smith et al.(2005)

Smith, S. M., J. S. Friedman, S. Raizada, C. A. Tepley, J. Baumgardner, and M. Mendillo, Simultaneous imaging and lidar measurements of a large breaking gravity wave event at Arecibo Observatory ( $18.3^{\circ}$ N, $66.8^{\circ}$ W), J. Atmos. Sol. Terr. Phys., 67, 345-356, doi: rm10.1016/j.jastp.2004.11.008, 2005.

Swartz et al.(2002)

Swartz, W. E., S. C. Collins, M. C. Kelley, J. J. Makela, E. Kudeki, S. Franke, J. Urbina, N. Aponte, S. González, M. P. Sulzer, and J. S. Friedman, First observations of an F-region turbulent upwelling coincident with severe E-region plasma and neutral atmosphere perturbations, J. Atmos. Solar-Terr. Phys., 64(12-14), 1545-1556, doi: rm10.1016/S1364-6826(02)00092-5, 2002.

Tepley et al.(2003)

Tepley, C. A., S. Raizada, Q. Zhou, and J. S. Friedman, Correction to ``First simultaneous observations of Ca $^{+}$ , K, and electron density using lidar and incoherent scatter radar at Arecibo'', Geophys. Res. Letters, 30, 56-1, 2003.

Tepley et al.(2003)

Tepley, C. A., S. Raizada, Q. H. Zhou, and J. S. Friedman, First simultaneous observations of $\rm {Ca}{^+}$ , K, and electron density using lidar and incoherent scatter radar at Arecibo, Geophys. Res. Letters, 30, 1009, doi:10.1029/2002GL015,927, 2003.

Tepley et al.(2005)

Tepley, C. A., J. S. Friedman, S. Raizada, and R. Garcia, AGU Spring Meeting Abstracts, in , p. A12, 2005.

Wiig et al.(2008)

Wiig, J., S. Raizada, X. Chu, and J. Friedman, 37th COSPAR Scientific Assembly, in , COSPAR Meeting, vol. 37, p. 3465, 2008.

Yue et al.(2012)

Yue, X., Q. Zhou, S. Raizada, C. Tepley, and J. Friedman, Relationship between mesospheric Na and Fe layers from simultaneous and common-volume lidar observations at Arecibo, J. Geophys. Res., 118, 1-12, doi: rm10.1029/2012JD018988, 2012.

Zhou et al.(2004)

Zhou, Q., J. Friedman, N. Aponte, M. Sulzer, S. Raizada, C. Tepley, S. Gonzalez, and Y. Morton, Incoherent scatter radar and optical observations of the mesosphere and lower thermosphere at Arecibo, in 35th COSPAR Scientific Assembly, COSPAR Meeting, vol. 35, edited by J.-P. Paillé, p. 1591, 2004.

Zhou et al.(2005)

Zhou, Q., J. Friedman, S. Raizada, C. Tepley, and Y. T. Morton, Morphology of nighttime ion, potassium and sodium layers in the meteor zone above Arecibo, J. Atmos. Sol. Terr. Phys., 67, 1245-1257, doi: rm10.1016/j.jastp.2005.06.013, 2005.