ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-7-4107-2007 Satellite measurements of the global mesospheric sodium layer Fan Z. Y. 1 Plane J. M. C. 2 Gumbel J. 3 Stegman J. 3 Llewellyn E. J. 4 School of Environmental Sciences, University of East Anglia, Norwich NR4 7TJ, UK School of Chemistry, University of Leeds, Leeds, LS2 9JT, UK Department of Meteorology, Stockholm University, 10691 Stockholm, Sweden ISAS, Department of Physics and Engineering Physics, University of Saskatchewan, Saskatoon, SK S7N 5E2, Canada 06 08 2007 7 15 4107 4115 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys.net/7/4107/2007/acp-7-4107-2007.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/7/4107/2007/acp-7-4107-2007.pdf

Optimal estimation theory is used to retrieve the absolute Na density profiles in the mesosphere/lower thermosphere from limb-scanning measurements of the Na radiance at 589 nm in the dayglow. Two years of observations (2003 and 2004), recorded by the OSIRIS spectrometer on the Odin satellite, have been analysed to yield the seasonal and latitudinal variation of the Na layer column abundance, peak height, and peak width. The layer shows little seasonal variation at low latitudes, but the winter/summer ratio increases from a factor of ~3 at mid-latitudes to ~10 in the polar regions. Comparison of the measurements made at about 06:00 and 18:00 LT shows little diurnal variation in the layer, apart from the equatorial region where, during the equinoxes, there is a two-fold increase in Na density below 94 km between morning and evening. This is most likely caused by the strong downward wind produced by the diurnal tide between ~02:00 and 10:00 LT. The dramatic removal of Na below 85 km at latitudes above 50° during summer is explained by the uptake of sodium species on the ice surfaces of polar mesospheric clouds, which were simultaneously observed by the Odin satellite.

 References Bernard, R.: The identification and the origin of atmospheric sodium, Astrophysical Journal, 89, 133-135, 1939. Blamont, J. E. and Donahue, T. M.: The Dayglow of the Sodium D Lines, J. Geophys. Res., 66, 1407–1427, 1961. Bowman, M. R., Gibson, A. J., and Sandford, M. C.: Atmospheric Sodium Measured by a Tuned Laser Radar, Nature, 221, 456–458, 1969. Chamberlain, J. W.: Resonance Scattering by Atmospheric Sodium. 1. Theory of the Intensity Plateau in the Twilight Airglow, J. Atmos. Terr. Phys., 9, 73–89, 1956. Chapman, S.: Notes on atmospheric sodium, J. Astrophys., 90, 309–316, 1939. Clemesha, B. R., Kirchhoff, V. W. K. H., and Simonich, D. M.: Concerning the Seasonal-Variation of the Mesospheric Sodium Layer at Low-Latitudes, Planet. Space Sci., 27, 909–910, 1979. Clemesha, B. R., Simonich, D. M., Batista, P. P., and Kirchhoff, V. W. K. H.: The diurnal variation of atmospheric sodium, J. Geophys. Res., 87, 181–186, 1982. Clemesha, B. R., Sahai, Y., Simonich, D. M., and Takahashi, H.: Nighttime Na-D Emission Observed from a Polar-Orbiting DMSP Satellite – Comment, J. Geophys. Res., 95, 6601–6606, 1990. Clemesha, B. R., Simonich, D. M., Batista, P. P., Vondrak, T., and Plane, J. M. C.: Negligible long-term temperature trend in the upper atmosphere at 23o S, J. Geophys. Res., 109, D05302, doi:05310.01029/02003JD004243, 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., Self, D. E., and Plane, J. M. C.: A study of the reaction between NaHCO3 and H: Apparent closure on the chemistry of mesospheric Na, J. Geophys. Res., 106, 1733–1739, 2001. Donahue, T. M. and Meier, R. R.: Distribution of Sodium in Daytime Upper Atmosphere as Measured by a Rocket Experiment, J. Geophys. Res., 72, 2803–2821, 1967. Fussen, D., Vanhellemont, F., Bingen, C., Kyrola, E., Tamminen, J., Sofieva, V., Hassinen, S., Seppala, A., Verronen, P., Bertaux, J. L., Hauchecorne, A., Dalaudier, F., Renard, J. B., Fraisse, R., d'Andon, O. F., Barrot, G., Mangin, A., Theodore, B., Guirlet, M., Koopman, R., Snoeij, P., and Saavedra, L.: Global measurement of the mesospheric sodium layer by the star occultation instrument GOMOS, Geophys. Res. Lett., 31, L24110, doi:24110.21029/22004GL021618, 2004. Gardner, C. S., Senft, D. C., and Kwon, K. H.: Lidar Observations of Substantial Sodium Depletion in the Summertime Arctic Mesosphere, Nature, 332, 142–144, 1988. Gardner, C. S., Plane, J. M. C., Pan, W., Vondrak, 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, J. Geophys. Res., 110, D10302, doi.10310.11029/12004JD005670, 2005. Gibson, A. J. and Sandford, M. C. W.: The seasonal variation of the night-time sodium layer, J. Atmos. Terr. Phys., 33, 1675–1684, 1971. Gibson, A. J. and Sandford, M. C. W.: Daytime Laser Radar Measurements of Atmospheric Sodium Layer, Nature, 239, 509–511, 1972. Gumbel, J., Fan, Z. Y., Waldemarsson, T., Stegman, J., Llewellyn, E. J., She, C.-Y., and Plane, J. M. C.: Retrievals of global mesospheric sodium densities from the Odin satellite, Geophys. Res. Lett., 34, L04813, doi:04810.01029/02006GL028687, 2007. Hagan, M. E. and Forbes, J. M.: Migrating and nonmigrating diurnal tides in the middle and upper atmosphere excited by tropospheric latent heat release, J. Geophys. Res., 107, 4754, doi:4710.1029/2001JD001236, 2002. Hunten, D. M.: A study of sodium in twilight. I. Theory, J. Atmos. Terr. Phys., 5, 44–56, 1954. Hunten, D. M.: Spectroscopic studies of the twilight airglow, Space Sci. Rev., 6, 493–573, 1967. Hunten, D. M., Jones, A. V., Ellyett, C. D., and , McLauchlan, E. C.: Sodium twilight at Christchurch, New Zealand, J. Atmos. Terr. Phys., 26, 67–76, 1964. 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, Geophys. Res. Lett., 18, 1365–1368, 1991. Kirchhoff, V. and Clemesha, B. R.: The Atmospheric Neutral Sodium Layer .2. Diurnal Variations, J. Geophys. Res., 88, 442–450, 1983. Livesey, N. J., Read, W. G., Froidevaux, L., Waters, J. W., Santee, M. L., Pumphrey, H. C., Wu, D. L., Shippony, Z., and Jarnot, R. F.: The UARS microwave limb sounder version 5 data set: Theory, characterization, and validation J. Geophys. Res., 108, 4378, doi:4310.1029/2002JD002273, 2003. Llewellyn, E. J., Lloyd, N. D., Degenstein, D. A., Gattinger, R. L., Petelina, S. V., Bourassa, A. E., Wiensz, J. T., Ivanov, E. V., McDade, I. C., Solheim, B. H., McConnell, J. C., Haley, C. S., von Savigny, C., Sioris, C. E., McLinden, C. A., Griffioen, E., Kaminski, J., Evans, W. F. J., Puckrin, E., Strong, K., Wehrle, V., Hum, R. H., Kendall, D. J. W., Matsushita, J., Murtagh, D. P., Brohede, S., Stegman, J., Witt, G., Barnes, G., Payne, W. F., Piche, L., Smith, K., Warshaw, G., Deslauniers, D. L., Marchand, P., Richardson, E. H., King, R. A., Wevers, I., McCreath, W., Kyrola, E., Oikarinen, L., Leppelmeier, G. W., Auvinen, H., Megie, G., Hauchecorne, A., Lefevre, F., de La Noe, J., Ricaud, P., Frisk, U., Sjoberg, F., von Scheele, F., and Nordh, L.: The OSIRIS instrument on the Odin spacecraft, Canadian Journal of Physics, 82, 411–422, 2004. Lübken, F. J. and Höffner, J.: Experimental evidence for ice particle interaction with metal atoms at the high latitude summer mesopause region, Geophys. Res. Lett., 31, L08103, 08110.01029/02004GL019586, 2004. Megie, G. and Blamont, J. E.: Laser Sounding of Atmospheric Sodium Interpretation in Terms of Global Atmospheric Parameters, Planet. Space Sci., 25, 1093–1109, 1977. Murray, B. J. and Plane, J. M. C.: Uptake of Fe, Na and K atoms on low-temperature ice: implications for metal atom scavenging in the vicinity of polar mesospheric clouds, Phys. Chem. Chem. Phys., 7, 3970–3979, 2005. Murtagh, D., Frisk, U., Merino, F., Ridal, M., Jonsson, A., Stegman, J., Witt, G., Eriksson, P., Jimenez, C., Megie, G., de la Noe, J., Ricaud, P., Baron, P., Pardo, J. R., Hauchcorne, A., Llewellyn, E. J., Degenstein, D. A., Gattinger, R. L., Lloyd, N. D., Evans, W. F. J., McDade, I. C., Haley, C. S., Sioris, C., von Savigny, C., Solheim, B. H., J. C. McConnell, K. Strong, E. H. Richardson, Leppelmeier, G. W., Kyrola, E., Auvinen, H., and Oikarinen, L.: An overview of the Odin atmospheric mission, Can. J. Phys., 80, 309–319, 2002. Newman, A. L.: Nighttime Na D emission observed from a polar-orbiting DMSP satellite, J. Geophys. Res., 93, 4067–4075, 1988. Petelina, S. V., Llewellyn, E. J., Degenstein, D. A., and Lloyd, N. D.: Odin/OSIRIS limb observations of polar mesospheric clouds in 2001–2003, J. Atmos. Solar-Terr. Phys., 68, 42–55, 2006. Picone, J. M., Hedin, A. E., Drob, D. P., and Aikin, A. C.: NRLMSISE-00 empirical model of the atmosphere: Statistical comparisons and scientific issues, J. Geophys. Res., 107, 1468, doi:1410.1029/2002JA009430, 2002. Plane, J. M. C.: Atmospheric chemistry of meteoric metals, Chem. Rev., 103, 4963–4984, 2003. Plane, J. M. C.: A time-resolved model of the mesospheric Na layer: constraints on the meteor input function, Atmos. Chem. Phys., 4, 627–638, 2004. 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., 103, 6381–6389, 1998. Plane, J. M. C., Gardner, C. S., Yu, J. R., She, C. Y., Garcia, R. R., and H. C.,: Mesospheric Na layer at 40° N: Modeling and observations, J. Geophys. Res., 104, 3773–3788, 1999. Plane, J. M. C., Murray, B. J., Chu, X., and Gardner, C. S.: Removal of Meteoric Iron on Polar Mesospheric Clouds, Science, 304, 426–428, 2004. Portnyagin, Y. I., Solovjova, T. V., Makarov, N. A., Merzlyakov, E. G., Manson, A. H., Meek, C. E., Hocking, W., Mitchell, N., Pancheva, D., Hoffmann, P., Singer, W., Murayama, Y. Igarashi,, K., Forbes, J. M., Palo, S., Hall, C., and Nozawa, S.: Monthly mean climatology of the prevailing winds and tides in the Arctic mesosphere/lower thermosphere, Annal. Geophys., 22, 3395–3410, 2004. Rodgers, C. D.: Inverse methods for atmospheric sounding : theory and practice, 238 pp., World Scientific, Singapore, 2000. Russell, J. P., Ward, W. E., Lowe, R. P., Roble, R. G., Shepherd, G. G., and Solheim, B.: Atomic oxygen profiles (80 to 115 km) derived from Wind Imaging Interferometer/Upper Atmospheric Research Satellite measurements of the hydroxyl and greenline airglow: Local time-latitude dependence, J. Geophys. Res., 110, D15305, doi:15310.11029/12004JD005570, 2005. She, C. Y., Chen, S. S., Hu, Z. L., Sherman, J., Vance, J. D., Vasoli, V., White, M. A., Yu, J. R., an Krueger, D. A.: Eight-year climatology of nocturnal temperature and sodium density in the mesopause region (80 to 105 km) over Fort Collins, CO (41° N, 105° W), Geophys. Res. Lett., 27, 3289–3292, 2000. She, C. Y., Williams, B. P., Hoffmann, P., Latteck, R., Baumgarten, G., Vance, J. D., Fiedler, J., Acott, P., Fritts, D. C., and Lübken, F. J.: Simultaneous observation of sodium atoms, NLC and PMSE in the summer mesopause region above ALOMAR, Norway (69° N, 12° E), J. Atmos. Solar-Terr. Phys., 68, 93–101, 2006. Slipher, V. M.: Emissions in the spectrum of the light of the night sky, Publ. Astron. Soc. Pacific, 41, 262–265, 1929. States, R. J. and Gardner, C. S.: Structure of the mesospheric Na layer at 40° N latitude: Seasonal and diurnal variations, J. Geophys. Res., 104, 11 783–11 798, 1999. Tilgner, C. and von Zahn, U.: Average Properties of the Sodium Density Distribution as Observed at 69° N Latitude in Winter, J. Geophys. Res., 93, 8439–8454, 1988. von Zahn, U., Hansen, G., and Kurzawa, H.: Observations of the sodium layer at high latitudes in summer, Nature, 331, 594–596, 1988. Xu, J. Y., Smith, A. K., and Wu, Q.: A retrieval algorithm for satellite remote sensing of the nighttime global distribution of the sodium layer J. Atmos. Solar-Terr. Phys., 67, 739–748, 2005