کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
8139911 | 1523603 | 2016 | 17 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Variability of mesospheric water vapor above Bern in relation to the 27-day solar rotation cycle
ترجمه فارسی عنوان
تغییرات بخار آب مازوفری در بالا برن نسبت به چرخه چرخشی 27 روزه خورشیدی
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فیزیک زمین (ژئو فیزیک)
چکیده انگلیسی
Many studies investigated solar-terrestrial responses (thermal state, O3, OH, H2O) with emphasis on the tropical upper atmosphere. In this paper the focus is switched to water vapor in the mesosphere at a mid-latitudinal location. Eight years of water vapor profile measurements above Bern (46.88°N/7.46°E) are investigated to study oscillations with the focus on periods between 10 and 50 days. Different spectral analyses revealed prominent features in the 27-day oscillation band, which are enhanced in the upper mesosphere (above 0.1hPa, â¼64km) during the rising sunspot activity of solar cycle 24. Local as well as zonal mean Aura MLS observations support these results by showing a similar behavior. The relationship between mesospheric water and the solar Lyman-α flux is studied by comparing the similarity of their temporal oscillations. The H2O oscillation is negatively correlated to solar Lyman-α oscillation with a correlation coefficient of up to â0.3 to â0.4, and the phase lag is 6-10 days at 0.04hPa. The confidence level of the correlation is â¥99%. This finding supports the assumption that the 27-day oscillation in Lyman-α causes a periodical photodissociation loss in mesospheric water. Wavelet power spectra, cross-wavelet transform and wavelet coherence analysis (WTC) complete our study. More periods of high common wavelet power of H2O and solar Lyman-α are present when amplitudes of the Lyman-α flux increase. Since this is not a measure of physical correlation a more detailed view on WTC is necessary, where significant (two sigma level) correlations occur intermittently in the 27 and 13-day band with variable phase lock behavior. Large Lyman-α oscillations appeared after the solar superstorm in July 2012 and the H2O oscillations show a well pronounced anti-correlation. The competition between advective transport and photodissociation loss of mesospheric water vapor may explain the sometimes variable phase relationship of mesospheric H2O and solar Lyman-α oscillations. Generally, the WTC analysis indicates that solar variability causes observable photochemical and dynamical processes in the mid-latitude mesosphere.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volumes 143â144, June 2016, Pages 71-87
Journal: Journal of Atmospheric and Solar-Terrestrial Physics - Volumes 143â144, June 2016, Pages 71-87
نویسندگان
Martin Lainer, Klemens Hocke, Niklaus Kämpfer,