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<front>
<journal-meta>
<journal-id journal-id-type="publisher">ARS</journal-id>
<journal-title-group>
<journal-title>Advances in Radio Science</journal-title>
<abbrev-journal-title abbrev-type="publisher">ARS</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Adv. Radio Sci.</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1684-9973</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/ars-12-205-2014</article-id>
<title-group>
<article-title>Seasonal and inter-annual variability of the quasi 2 day wave over Collm (51.3&amp;deg; N, 13&amp;deg; E) as obtained from VHF meteor radar measurements</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Lilienthal</surname>
<given-names>F.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Jacobi</surname>
<given-names>Ch.</given-names>
<ext-link>https://orcid.org/0000-0002-7878-0110</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institute for Meteorology, University of Leipzig, Stephanstr. 3, 04103 Leipzig, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>10</day>
<month>11</month>
<year>2014</year>
</pub-date>
<volume>12</volume>
<fpage>205</fpage>
<lpage>210</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2014 F. Lilienthal</copyright-statement>
<copyright-year>2014</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/3.0/">https://creativecommons.org/licenses/by/3.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://ars.copernicus.org/articles/12/205/2014/ars-12-205-2014.html">This article is available from https://ars.copernicus.org/articles/12/205/2014/ars-12-205-2014.html</self-uri>
<self-uri xlink:href="https://ars.copernicus.org/articles/12/205/2014/ars-12-205-2014.pdf">The full text article is available as a PDF file from https://ars.copernicus.org/articles/12/205/2014/ars-12-205-2014.pdf</self-uri>
<abstract>
<p>The quasi 2 day wave (QTDW) over Collm (51&amp;deg; N, 13&amp;deg; E) has
been studied between September 2004 and September 2013 using a VHF meteor
radar. The 9 year mean amplitudes show a strong summer maximum with
several irregular bursts and much weaker winter maxima. In summer, the
meridional amplitude is slightly larger than the zonal one with about
15 m s&lt;sup&gt;−1&lt;/sup&gt; at 91 km height. Phase differences are slightly higher
than 90&amp;deg;, which indicates a polarization that is nearly circular. On
an average the QTDW is amplified after a maximum of zonal wind shear. This
can be realized in the summer mesospheric jet where the zonal wind component
has its minimum or, in other words, the easterly jet maximizes. Thus,
instability is found as a likely forcing mechanism. QTDW amplitudes exhibit
considerable inter-annual variability. In particular, there is a possible
relation between the QTDW amplitude and the 11-year solar cycle in winter but
not in summer.</p>
</abstract>
<counts><page-count count="6"/></counts>
</article-meta>
</front>
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<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple">Babadshanov, P. B., Kalchenko, B. V., Kashcheyev, B. L., and Fedynsky, V. V.: Winds in the equatorial lower thermosphere, Proc. Acad. Sci. USSR, 208, 1334–1337, 1973 (in Russian).</mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple">Bristow, W. A., Yee, J.-H., Zhu, X., and Greenwald, R. A.: Simultaneous observations of the July 1996 2-day wave event using the Super Dual Auroral Radar Network and the High Resolution Doppler Imager, J. Geophys. Res., 104, 12715–12721, &lt;a href=&quot;http://dx.doi.org/10.1029/1999JA900030&quot;&gt;https://doi.org/10.1029/1999JA900030&lt;/a&gt;, 1999.</mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple">Charney, J. G. and Stern, M. E.: On the Stability of Internal Baroclinic Jets in a Rotating Atmosphere, J. Atmos. Sci., 19, 159–172, &lt;a href=&quot;http://dx.doi.org/10.1175/1520-0469(1962)019&lt;0159:OTSOIB&gt;2.0.CO;2&quot;&gt;https://doi.org/10.1175/1520-0469(1962)019&lt;0159:OTSOIB&gt;2.0.CO;2&lt;/a&gt;, 1962.</mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple">Craig, R. L. and Elford, W. G.: Observations of the quasi 2day wave near 90 km altitude at Adelaide (35\degree S), J. Atmos. Terr. Phys., 43, 1051–1056, &lt;a href=&quot;http://dx.doi.org/10.1016/0021-9169(81)90019-2&quot;&gt;https://doi.org/10.1016/0021-9169(81)90019-2&lt;/a&gt;, 1981.</mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple">Ern, M., Preusse, P., Kalisch, S., Kaufmann, M., and Riese, M.: Role of gravity waves in the forcing of the quasi two-day waves in the mesosphere: An observational study, J. Geophys. Res., 118, 3467–3485, &lt;a href=&quot;http://dx.doi.org/10.1029/2012JD018208&quot;&gt;https://doi.org/10.1029/2012JD018208&lt;/a&gt;, 2013.</mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple">Gurubaran, S., Sridharan, S., Ramkumar, T. K., and Rajaram, R.: The mesospheric quasi-2-day wave over Tirunelveli (8.7&amp;deg; N), J. Atmos. Sol.-Terr. Phy., 63, 975–985, &lt;a href=&quot;http://dx.doi.org/10.1016/S1364-6826(01)00016-5&quot;&gt;https://doi.org/10.1016/S1364-6826(01)00016-5&lt;/a&gt;, 2001.</mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple">Hocking, W., Fuller, B., and Vandepeer, B.: Real-time determination of meteor-related parameters utilizing modern digital technology, J. Atmos. Sol.-Terr. Phy., 63, 155–169, &lt;a href=&quot;http://dx.doi.org/10.1016/S1364-6826(00)00138-3&quot;&gt;https://doi.org/10.1016/S1364-6826(00)00138-3&lt;/a&gt;, 2001.</mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple">Jacobi, C.: 6 year mean prevailing winds and tides measured by VHF meteor radar over Collm (51.3&amp;deg; N, 13.0&amp;deg; E), J. Atmos. Sol.-Terr. Phys., 78–79, 8–18, &lt;a href=&quot;http://dx.doi.org/10.1016/j.jastp.2011.04.010&quot;&gt;https://doi.org/10.1016/j.jastp.2011.04.010&lt;/a&gt;, 2012.</mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple">Jacobi, C., Schminder, R., and Kürschner, D.: The quasi 2-day wave as seen from Dl LF wind measurements over Central Europe (52° N, 15° E) at Collm, J. Atmos. Sol.-Terr. Phy., 59, 1277–1286, &lt;a href=&quot;http://dx.doi.org/10.1016/S1364-6826(96)00170-8&quot;&gt;https://doi.org/10.1016/S1364-6826(96)00170-8&lt;/a&gt;, 1997.</mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple">Jacobi, C., Portnyagin, Y. I., Merzlyakov, E. G., Kashcheyev, B. L., Oleynikov, A., Kürschner, D., Mitchell, N. J., Middleton, H., Muller, H. G., and Comley, V. E.: Mesosphere/lower thermosphere wind measurements over Europe in summer 1998, J. Atmos. Sol.-Terr. Phy., 63, 1017–1031, &lt;a href=&quot;http://dx.doi.org/10.1016/S1364-6826(01)00012-8&quot;&gt;https://doi.org/10.1016/S1364-6826(01)00012-8&lt;/a&gt;, 2001.</mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple">Jacobi, Ch., Hoffmann, P., Placke, M., and Stober, G.: Some anomalies of mesosphere/lower thermosphere parameters during the recent solar minimum, Adv. Radio Sci., 9, 343–348, &lt;a href=&quot;http://dx.doi.org/10.5194/ars-9-343-2011&quot;&gt;https://doi.org/10.5194/ars-9-343-2011&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple">Malinga, S. B. and Ruohoniemi, J. M.: The quasi-two-day wave studied using the Northern Hemisphere SuperDARN HF radars, Ann. Geophys., 25, 1767–1778, &lt;a href=&quot;http://dx.doi.org/10.5194/angeo-25-1767-2007&quot;&gt;https://doi.org/10.5194/angeo-25-1767-2007&lt;/a&gt;, 2007.</mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple">Merzlyakov, E. G. and Jacobi, Ch.: Quasi-two-day wave in an unstable summer atmosphere – some numerical results on excitation and propagation, Ann. Geophys., 22, 1917–1929, &lt;a href=&quot;http://dx.doi.org/10.5194/angeo-22-1917-2004&quot;&gt;https://doi.org/10.5194/angeo-22-1917-2004&lt;/a&gt;, 2004.</mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple">Muller, H. G.: Long-period meteor wind oscillations, Phil. T. R. Soc. A, 271, 585–598, 1972.</mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple">Muller, H. G. and Nelson, L.: A travelling quasi 2-day wave in the meteor region, J. Atmos. Terr. Phys., 40, 761–766, 1978.</mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple">Nozawa, S., Imaida, S., Brekke, A., Hall, C. M., Manson, A., Meek, C., Oyama, S., Dobashi, K., and Fujii, R.: The quasi 2-day wave observed in the polar mesosphere, J. Geophys. Res., 108, 4039, &lt;a href=&quot;http://dx.doi.org/10.1029/2002JD002440&quot;&gt;https://doi.org/10.1029/2002JD002440&lt;/a&gt;, 2003.</mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple">Palo, S. E., Roble, R. G., and Hagan, M. E.: Middle atmosphere effects of the quasi-two-day wave determined from a General Circulation Model, Earth Planets Space, 51, 629–647, 1999.</mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple">Pancheva, D. V.: Quasi-2-day wave and tidal variability observed over Ascension Island during January/February 2003, J. Atmos. Sol.-Terr. Phy., 68, 390–407, &lt;a href=&quot;http://dx.doi.org/10.1016/j.jastp.2005.02.028&quot;&gt;https://doi.org/10.1016/j.jastp.2005.02.028&lt;/a&gt;, 2006.</mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple">Pancheva, D. V., Mitchell, N. J., Manson, A. H., Meek, C. E., Jacobi, C., Portnyagin, Y., Merzlyakov, E., Hocking, W. K., MacDougall, J., Singer, W., Igarashi, K., Clark, R. R., Riggin, D. M., Franke, S. J., Kürschner, D. K., Fahrutdinova, A. N., Stepanov, A. M., Kashcheyev, B. L., Oleynikovm, A. N., and Muller, H. G.: Variability of the quasi-2-day wave observed in the MLT region during the PSMOS campaign of June–August 1999, J. Atmos. Sol.-Terr. Phy., 66, 539–565, &lt;a href=&quot;http://dx.doi.org/10.1016/j.jastp.2004.01.008&quot;&gt;https://doi.org/10.1016/j.jastp.2004.01.008&lt;/a&gt;, 2004.</mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple">Pendlebury, D.: A simulation of the quasi-two-day wave and its effect on variability of summertime mesopause temperatures, J. Atmos. Sol.-Terr. Phy., 80, 138–151, &lt;a href=&quot;http://dx.doi.org/10.1016/j.jastp.2012.01.006&quot;&gt;https://doi.org/10.1016/j.jastp.2012.01.006&lt;/a&gt;, 2012.</mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple">Pfister, L.: Baroclinic instability of easterly jets with applications to the summer mesosphere, J. Atmos. Sci., 42, 313–330, &lt;a href=&quot;http://dx.doi.org/10.1175/1520-0469(1985)042&lt;0313:BIOEJW&gt;2.0.CO;2&quot;&gt;https://doi.org/10.1175/1520-0469(1985)042&lt;0313:BIOEJW&gt;2.0.CO;2&lt;/a&gt;, 1985.</mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple">Plumb, R. A.: Baroclinic Instability of the Summer Mesosphere: A Mechanism for the Quasi-Two-Day Wave?, J. Atmos. Sci., 40, 262–270, 1983.</mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple">Plumb, R. A., Vincent, R. A., and Craig, R. L.: The Quasi-Two-Day Wave Event of January 1984 and its Impact an the Mean Mesospheric Circulation, J. Atmos. Sci., 44, 3030–3036, 1987.</mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple">Salby, M. L.: Rossby normal modes in nonuniform background configurations. Part II: Equinox and solstice conditions, J. Atmos. Sci., 38, 1827–1840, 1981a.</mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple">Salby, M. L.: The 2-day wave in the middle atmosphere – observations and theory, J. Geophys. Res., 86, 9654–9660, 1981b.</mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple">Salby, M. L. and Callaghan, P. F.: Seasonal amplification of the 2-day wave: Relationship between normal mode and instability, J. Atmos. Sci., 58, 1858–1869, &lt;a href=&quot;http://dx.doi.org/10.1175/1520-0469(2001)058&lt;1858:SAOTDW&gt;2.0.CO;2&quot;&gt;https://doi.org/10.1175/1520-0469(2001)058&lt;1858:SAOTDW&gt;2.0.CO;2&lt;/a&gt;, 2001.</mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple">Stober, G., Jacobi, C., Fröhlich, K., and Oberheide, J.: Meteor radar temperatures over Collm (51.3\degree N, 13\degree E), Adv. Space Res., 42, 1253–1258, &lt;a href=&quot;http://dx.doi.org/10.1016/j.asr.2007.10.018&quot;&gt;https://doi.org/10.1016/j.asr.2007.10.018&lt;/a&gt;, 2008.</mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple">Tsuda, T., Kato, S., and Vincent, R. A.: Long period wind oscillations observed by the Kyoto meteor radar and comparison of the quasi-2-day wave with Adelaide HF radar obervations, J. Atmos. Terr. Phys., 50, 225–230, &lt;a href=&quot;http://dx.doi.org/10.1016/0021-9169(88)90071-2&quot;&gt;https://doi.org/10.1016/0021-9169(88)90071-2&lt;/a&gt;, 1988.</mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple">Tunbridge, V. M., Sandford, D. J., and Mitchell, N. J.: Zonal wave numbers of the summertime 2 day planetary wave observed in the mesosphere by EOS Aura Microwave Limb Sounder, J. Geophys. Res., 116, D11103, &lt;a href=&quot;http://dx.doi.org/10.1029/2010JD014567&quot;&gt;https://doi.org/10.1029/2010JD014567&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple">Wu, D. L., Fishbein, E. F., Read, W. G., and Waters, J. W.: Excitation and Evolution of the Quasi 2-Day Wave Observed in UARS/MLS Temperature Measurements, J. Atmos. Sci., 53, 728–738, &lt;a href=&quot;http://dx.doi.org/10.1175/1520-0469(1996)053&lt;0728:EAEOTQ&gt;2.0.CO;2&quot;&gt;https://doi.org/10.1175/1520-0469(1996)053&lt;0728:EAEOTQ&gt;2.0.CO;2&lt;/a&gt;, 1996.</mixed-citation>
</ref>
</ref-list>
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