ACP Atmospheric Chemistry and Physics ACP 1680-7324 Copernicus GmbH Göttingen, Germany 10.5194/acp-12-3753-2012 First detection of tidal behaviour in polar mesospheric water vapour by ground based microwave spectroscopy Hallgren K. 1 Hartogh P. 1 Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany 24 04 2012 12 8 3753 3759 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/12/3753/2012/acp-12-3753-2012.html The full text article is available as a PDF file from http://www.atmos-chem-phys.net/12/3753/2012/acp-12-3753-2012.pdf

Mesospheric water vapour has been observed above ALOMAR in northern Norway (69° N 16° E) by our group since 1995 using a 22 GHz ground based microwave spectrometer. A new instrument with higher sensitivity, providing a much better time resolution especially in the upper mesosphere, was installed in May 2008. The time resolution is high enough to provide observations of daily variations in the water vapour mixing ratio. We present the first ground based detections of tidal behaviour in the polar middle atmospheric water vapour distribution. <br><br> Diurnal and semidiurnal variations of water vapour have been observed and due to the long chemical lifetime of water they are assumed to be caused by changing wind patterns which transport water-rich or poor air into the observed region. The detected tidal behaviour does not follow any single other dynamical field but is instead assumed to be a result of the different wind components. <br><br> Both the diurnal and semidiurnal amplitude and phase components are resolved. The former shows a stable seasonal behaviour consistent with earlier observations of wind fields and model calculations, whereas the latter appears more complex and no regular behaviour has so far been observed.

 References Brasseur, G. and Solomon, S.: Aeronomy of the middle atmosphere, D. Reidel Publishing Company, 1998. Fleming, E L., Chandra, S., Barnett, J., and Corney, M.: Zonal mean temperature, pressure, zonal wind and geopotential height as functions of latitude, Adv. Space Res., 10, 11–59, http://dx.doi.org/10.1016/0273-1177(90)90386-Edoi:10.1016/0273-1177(90)90386-E, 1990. Forbes, J M.: Atmospheric tides. I - Model description and results for the solar diurnal component, J. Geophys. Res., 87, 5222–5241, http://dx.doi.org/10.1029/JA087iA07p05222doi:10.1029/JA087iA07p05222, 1982a. Forbes, J M.: Atmospheric tides. II – The solar and lunar semidiurnal components, J. Geophys. Res., 87, 5241–5252, http://dx.doi.org/10.1029/JA087iA07p05241doi:10.1029/JA087iA07p05241, 1982b. Forbes, J M. and Wu, D.: Solar Tides as Revealed by Measurements of Mesosphere Temperature by the MLS Experiment on UARS, Journal of Atmospheric Sciences, 63, 1776–1797, http://dx.doi.org/10.1175/JAS3724.1doi:10.1175/JAS3724.1, 2006. Fritts, D C. and Vincent, R A.: Mesospheric momentum flux studies at Adelaide, Australia – Observations and a gravity wave-tidal interaction model, Journal of Atmospheric Sciences, 44, 605–619, http://dx.doi.org/10.1175/1520-0469(1987)044<0605:MMFSAA>2.0.CO;2doi:10.1175/1520-0469(1987)044<0605:MMFSAA>2.0.CO;2, 1987. Haefele, A., Hocke, K., Kämpfer, N., Keckhut, P., Marchand, M., Bekki, S., Morel, B., Egorova, T., and Rozanov, E.: Diurnal changes in middle atmospheric H<sub>2</sub>O and O<sub>3</sub>: Observations in the Alpine region and climate models, J. Geophys. Res.-Atmos., 113, D17303, http://dx.doi.org/10.1029/2008JD009892doi:10.1029/2008JD009892, 2008. Hallgren, K.: Mesospheric water vapor – Variability at different timescales observed by ground-based microwave spectroscopy, Ph.D. Thesis, Universität Rostock, 2010. Hallgren, K., Hartogh, P., and Jarchow, C.: A New, High-performance, Heterodyne Spectrometer for Ground-based Remote Sensing of Mesospheric Water Vapour, World Scientific Publishing Co., 19, 569–578, 2010. Hartogh, P. and Hartmann, G K.: A high-resolution chirp transform spectrometer for microwave measurements, Meas. Sci. Technol., 1, 592–595, 1990. Hartogh, P. and Jarchow, C.: Groundbased detection of middle atmospheric water vapor, in: Global Process Monitoring and Remote Sensing of Ocean and Sea Ice, EUROPTO-Series 2586, 188–195, SPIE, Bellingham, 1995. Hartogh, P., Sonnemann, G R., Grygalashvyly, M., Song, L., Berger, U., and Lübken, F.: Water vapor measurements at ALOMAR over a solar cycle compared with model calculations by LIMA, J. Geophys. Res.-Atmos., 115, D00I17, http://dx.doi.org/10.1029/2009JD012364doi:10.1029/2009JD012364, 2010. Hays, P B., Wu, D L., and The Hrdi Science Team: Observations of the Diurnal Tide from Space., Journal of Atmospheric Sciences, 51, 3077–3093, http://dx.doi.org/10.1175/1520-0469(1994)051<3077:OOTDTF>2.0.CO;2doi:10.1175/1520-0469(1994)051<3077:OOTDTF>2.0.CO;2, 1994. Lübken, F.-J.: Thermal structure of the arctic summer mesosphere, J. Geophys. Res., 104, 9135–9150, http://dx.doi.org/10.1029/1999JD900076doi:10.1029/1999JD900076, 1999. Lübken, F.-J., Höffner, J., Viehl, T P., Kaifler, B., and Morris, R J.: First measurements of thermal tides in the summer mesopause region at Antarctic latitudes, 38, L24806, http://dx.doi.org/10.1029/2011GL050045doi:10.1029/2011GL050045, 2011. Manson, A. H., Luo, Y., and Meek, C.: Global distributions of diurnal and semi-diurnal tides: observations from HRDI-UARS of the MLT region, Ann. Geophys., 20, 1877–1890, http://dx.doi.org/10.5194/angeo-20-1877-2002doi:10.5194/angeo-20-1877-2002, 2002a. Manson, A. H., Meek, C., Hagan, M., Koshyk, J., Franke, S., Fritts, D., Hall, C., Hocking, W., Igarashi, K., MacDougall, J., Riggin, D., and Vincent, R.: Seasonal variations of the semi-diurnal and diurnal tides in the MLT: multi-year MF radar observations from 2–70° N, modelled tides (GSWM, CMAM), Ann. Geophys., 20, 661–677, http://dx.doi.org/10.5194/angeo-20-661-2002doi:10.5194/angeo-20-661-2002, 2002b. McLandress, C.: Seasonal variability of the diurnal tide: Results from the Canadian middle atmosphere general circulation model, J. Geophys. Res., 102, 29747–29764, http://dx.doi.org/10.1029/97JD02645doi:10.1029/97JD02645, 1997. McLandress, C.: The Seasonal Variation of the Propagating Diurnal Tide in the Mesosphere and Lower Thermosphere. Part I: The Role of Gravity Waves and Planetary Waves., Journal of Atmospheric Sciences, 59, 893–906, http://dx.doi.org/10.1175/1520-0469(2002)059<0893:TSVOTP>2.0.CO;2doi:10.1175/1520-0469(2002)059<0893:TSVOTP>2.0.CO;2, 2002a. McLandress, C.: The Seasonal Variation of the Propagating Diurnal Tide in the Mesosphere and Lower Thermosphere. Part II: The Role of Tidal Heating and Zonal Mean Winds., Journal of Atmospheric Sciences, 59, 907–922, http://dx.doi.org/10.1175/1520-0469(2002)059<0907:TSVOTP>2.0.CO;2doi:10.1175/1520-0469(2002)059<0907:TSVOTP>2.0.CO;2, 2002b. McPherson, R D., Bergman, K H., Kistler, R E., Rasch, G E., and Gordon, D S.: The NMC Operational Global Data Assimilation System, Mon. Weather Rev., 107, 1445–1461, http://dx.doi.org/10.1175/1520-0493(1979)107<1445:TNOGDA>2.0.CO;2doi:10.1175/1520-0493(1979)107<1445:TNOGDA>2.0.CO;2, 1979. Nedoluha, G E., Bevilacqua, R M., Michael Gomez, R., Waltman, W B., Hicks, B C., Thacker, D L., and Andrew Matthews, W.: Measurements of water vapor in the middle atmosphere and implications for mesospheric transport, J. Geophys. Res., 101, 21183–21194, http://dx.doi.org/10.1029/96JD01741doi:10.1029/96JD01741, 1996. Paganini, L. and Hartogh, P.: Analysis of nonlinear effects in microwave spectrometers, J. Geophys. Res.-Atmos., 114, D13305, http://dx.doi.org/10.1029/2008JD011141doi:10.1029/2008JD011141, 2009. Portnyagin, Y.: A review of mesospheric and lower thermosphere models, Adv. Space Res., 38, 2452–2460, http://dx.doi.org/10.1016/j.asr.2006.04.030doi:10.1016/j.asr.2006.04.030, 2006. 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, Ann. Geophys., 22, 3395–3410, http://dx.doi.org/10.5194/angeo-22-3395-2004doi:10.5194/angeo-22-3395-2004, 2004. Rodgers, C D.: Retrieval of Atmospheric Temperature and Composition From Remote Measurements of Thermal Radiation, Rev. Geophys. Space Ge., 14, 609–624, http://dx.doi.org/10.1029/RG014i004p00609doi:10.1029/RG014i004p00609, 1976. Rodgers, C D.: Characterization and error analysis of profiles retrieved from remote sounding measurements, J. Geophys. Res., 95, 5587–5595, http://dx.doi.org/10.1029/JD095iD05p05587doi:10.1029/JD095iD05p05587, 1990. Seele, C. and Hartogh, P.: Water vapor of the polar middle atmosphere: Annual variation and summer mesosphere conditions as observed by ground-based microwave spectroscopy, Geophys. Res. Lett., 26, 1517–1520, 1999. Seele, C. and Hartogh, P.: A case study on middle atmospheric water vapor transport during the February 1998 stratospheric warming, Geophys. Res. Lett., 26, 3309–3312, 2000. Sonnemann, G R., Hartogh, P., Grygalashvyly, M., Li, S., and Berger, U.: The quasi 5-day signal in the mesospheric water vapor concentration at high latitudes in 2003-a comparison between observations at ALOMAR and calculations, J. Geophys. Res.-Atmos., 113, D04101, http://dx.doi.org/10.1029/2007JD008875doi:10.1029/2007JD008875, 2008. Straub, C., Murk, A., Kämpfer, N., Golchert, S. H. W., Hochschild, G., Hallgren, K., and Hartogh, P.: ARIS-Campaign: intercomparison of three ground based 22 GHz radiometers for middle atmospheric water vapor at the Zugspitze in winter 2009, Atmos. Meas. Tech., 4, 1979–1994, http://dx.doi.org/10.5194/amt-4-1979-2011doi:10.5194/amt-4-1979-2011, 2011. Villanueva, G., and Hartogh, P.: The High Resolution Chirp Transform Spectrometer for the Sofia-Great Instrument, Exp. Astron., 18, 77–91, http://dx.doi.org/10.1007/s10686-005-9004-3doi:10.1007/s10686-005-9004-3, 2004. Villanueva, G L., Hartogh, P., and Reindl, L.: A digital dispersive matching network for SAW devices in chirp transform spectrometers, IEEE T. Microw. Theory, 54, 1415–1424, http://dx.doi.org/10.1109/TMTT.2006.871244doi:10.1109/TMTT.2006.871244, 2006. Vincent, R A., Tsuda, T., and Kato, S.: A comparative study of mesospheric solar tides observed at Adelaide and Kyoto, J. Geophys. Res., 93, 699–708, http://dx.doi.org/10.1029/JD093iD01p00699doi:10.1029/JD093iD01p00699, 1988. Wang, D. and Fritts, D C.: Evidence of Gravity Wave-Tidal Interaction Observed near the Summer Mesopause at Poker Flat, Alaska., Journal of Atmospheric Sciences, 48, 572–583, http://dx.doi.org/10.1175/1520-0469(1991)048<0572:EOGWIO>2.0.CO;2doi:10.1175/1520-0469(1991)048<0572:EOGWIO>2.0.CO;2, 1991. Zhang, X., Forbes, J M., and Hagan, M E.: Longitudinal variation of tides in the MLT region: 1. Tides driven by tropospheric net radiative heating, J. Geophys. Res.-Space, 115, A06316, http://dx.doi.org/10.1029/2009JA014897doi:10.1029/2009JA014897, 2010a. Zhang, X., Forbes, J M., and Hagan, M E.: Longitudinal variation of tides in the MLT region: 2. Relative effects of solar radiative and latent heating, J. Geophys. Res.-Space, 115, A06317, http://dx.doi.org/10.1029/2009JA014898doi:10.1029/2009JA014898, 2010b.