Seasonal climatology of the nighttime tidal perturbation of temperature in the midlatitude mesopause region

1998 ◽  
Vol 25 (17) ◽  
pp. 3301-3304 ◽  
Author(s):  
Bifford P. Williams ◽  
C. Y. She ◽  
Raymond G. Roble
2006 ◽  
Vol 19 (16) ◽  
pp. 3903-3931 ◽  
Author(s):  
H. Schmidt ◽  
G. P. Brasseur ◽  
M. Charron ◽  
E. Manzini ◽  
M. A. Giorgetta ◽  
...  

Abstract This paper introduces the three-dimensional Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), which treats atmospheric dynamics, radiation, and chemistry interactively for the height range from the earth’s surface to the thermosphere (approximately 250 km). It is based on the latest version of the ECHAM atmospheric general circulation model of the Max Planck Institute for Meteorology in Hamburg, Germany, which is extended to include important radiative and dynamical processes of the upper atmosphere and is coupled to a chemistry module containing 48 compounds. The model is applied to study the effects of natural and anthropogenic climate forcing on the atmosphere, represented, on the one hand, by the 11-yr solar cycle and, on the other hand, by a doubling of the present-day concentration of carbon dioxide. The numerical experiments are analyzed with the focus on the effects on temperature and chemical composition in the mesopause region. Results include a temperature response to the solar cycle by 2 to 10 K in the mesopause region with the largest values occurring slightly above the summer mesopause. Ozone in the secondary maximum increases by up to 20% for solar maximum conditions. Changes in winds are in general small. In the case of a doubling of carbon dioxide the simulation indicates a cooling of the atmosphere everywhere above the tropopause but by the smallest values around the mesopause. It is shown that the temperature response up to the mesopause is strongly influenced by changes in dynamics. During Northern Hemisphere summer, dynamical processes alone would lead to an almost global warming of up to 3 K in the uppermost mesosphere.


1992 ◽  
Vol 19 (1) ◽  
pp. 57-60 ◽  
Author(s):  
Richard L. Collins ◽  
Daniel C. Senft ◽  
Chester S. Gardner

2017 ◽  
Author(s):  
Rui Song ◽  
Martin Kaufmann ◽  
Jörn Ungermann ◽  
Manfred Ern ◽  
Guang Liu ◽  
...  

Abstract. Gravity waves (GWs) play an important role in atmospheric dynamics. Especially in the mesosphere and lower thermosphere (MLT) dissipating GWs provide a major contribution to the driving of the global wind system. Therefore global observations of GWs in the MLT region are of particular interest. The small scales of GWs, however, pose a major problem for the observation of GWs from space. We propose a new observation strategy for GWs in the mesopause region by combining limb and sub-limb satellite-borne remote sensing measurements for improving the spatial resolution of temperatures that are retrieved from atmospheric soundings. In our study, we simulate satellite observations of the rotational structure of the O2 A-band nightglow. A key element of the new method is the ability of the instrument or the satellite to operate in so called target mode, i.e. to stare at a particular point in the atmosphere and collect radiances at different viewing angles. These multi-angle measurements of a selected region allow for tomographic reconstruction of a 2-dimensional atmospheric state, in particular of gravity wave structures. As no real data is available, the feasibility of this tomographic retrieval is carried out with simulation data in this work. It shows that one major advantage of this observation strategy is that much smaller scale GWs can be observed. We derive a GW sensitivity function, and it is shown that target mode observations are able to capture GWs with horizontal wavelengths as short as ~ 50 km for a large range of vertical wavelengths. This is far better than the horizontal wavelength limit of 100–200 km obtained for conventional limb sounding.


Author(s):  
В.И. Сивцева ◽  
П.П. Аммосов ◽  
Г.А. Гаврильева ◽  
И.И. Колтовской ◽  
А.М. Аммосова

Исследованы данные температуры области мезопаузы, полученные за период 2013-2018 гг. на станции Маймага (63.04N, 129.51E) и за период 2015-2018 гг. на станции Тикси (71.58 N, 128.77 E). В зимний период сезона наблюдений 2014-2015 характеристика активности внутренних гравитационных волн (ВГВ) gwимеет более низкие значения, чем в другие сезоны, а средненочная температура, наоборот, превышает аналогичные значения в другие сезоны. Для сопоставления рассматривались спутниковые данные температурных профилей полученные EOS MLS (Aura). После выделения и вычитания вклада гравитационной составляющей из температурных профилей EOS MLS для области над станцией Маймага заметно отличие в зимней стратопаузе сезона 2014-2015. В этот сезон в зимний период, с учетом вычета вклада флуктуаций температуры обусловленных ВГВ, наблюдается отсутствие резких потеплений в районе стратопаузы в отличие от остальных сезонов. Измерение параметров планетарных волн в течение периода 2015-2018 гг. совместных наблюдений на станциях Маймага и Тикси показали, что фазы наблюдаемых на обеих станциях волн совпадают, а амплитуды на станции Тикси несколько (12 К) превышают амплитуды на станции Маймага. The temperature data of the mesopause region obtained for the period 2013-2018 at the station Maimaga (63.04 N, 129.51 E) and for the period 2015-2018 at the station Tiksi (71.58 N, 128.77 E) was investigated. During the winter period of the 20142015 observation season, the characteristic of the internal gravity waves (IGW) activity sgw has lower values than in other seasons, and the average night temperature of the mesopause region, on the contrary, exceeds corresponding values in other seasons. For comparison, satellite data of temperature profiles obtained by EOS MLS (Aura) are given. After isolating and subtracting the contribution of the gravitaty waves from the EOS MLS temperature profiles for the region above the st. Maimaga, the difference in the winter stratopause of the 2014-2015 season is noticeable. In this season in winter there is a lack of sharp warming in the stratopause region, in contrast to other seasons, taking into account the deduction of the contribution of temperature fluctuations due to IGW. Measurement of the parameters of planetary waves during the period 2015-2018 of joint observations at Maimaga and Tiksi stations showed that the phases of the waves observed at both stations coincide, and the amplitudes at Tiksi station are several (1-2 K) higher than the amplitudes at Maimaga station.


2018 ◽  
Author(s):  
Tilo Fytterer ◽  
Christian von Savigny ◽  
Martin Mlynczak ◽  
Miriam Sinnhuber

Abstract. An OH airglow model was developed to derive night-time atomic oxygen (O(3P)) and atomic hydrogen (H) from satellite OH airglow observations in the mesopause region (~ 75–100 km). The OH airglow model is based on the zero dimensional box model CAABA/MECCA-3.72f and was empirically adjusted to fit four different OH airglow emissions observed by the satellite/instrument configuration TIMED/SABER at 2.0 μm and at 1.6 μm as well as measurements by ENVISAT/SCIAMACHY of the transitions OH(6-2) and OH(3-1). Comparisons between the Best fit model obtained here and the satellite measurements suggest that deactivation of vibrationally excited OH(v) via OH(v ≥ 7) + O2 might favour relaxation to OH(v' ≤ 5) + O2 by multi-quantum quenching. It is further indicated that the deactivation pathway to OH(v' = v − 5) + O2 dominates. The results also provide general support of the recently proposed mechanism OH(v) + O(3P) → OH(0 ≤ v' ≤ v − 5) + O(1D) but suggest slower rates of OH(v = 7,6,5) + O(3P). Additionally, deactivation to OH(v' = v − 5) + O(1D) might be preferred. The profiles of O(3P) and H derived here are plausible between 80 km and 95  km. The values of O(3P) obtained in this study agree with the corresponding TIMED/SABER values between 80 km and 85 km, but are larger from 85 to 95 km due to different relaxation assumptions of OH(v) + O(3P). The H profile found here is generally larger than TIMED/SABER H by about 30–35 % from 80 to 95 km, which might be attributed to too high O3 night-time values.


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