Letteratura scientifica selezionata sul tema "Mesosphere"

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Articoli di riviste sul tema "Mesosphere"

1

Matthias, Vivien, e Manfred Ern. "On the origin of the mesospheric quasi-stationary planetary waves in the unusual Arctic winter 2015/2016". Atmospheric Chemistry and Physics 18, n. 7 (9 aprile 2018): 4803–15. http://dx.doi.org/10.5194/acp-18-4803-2018.

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Abstract. The midwinter 2015/2016 was characterized by an unusually strong polar night jet (PNJ) and extraordinarily large stationary planetary wave (SPW) amplitudes in the subtropical mesosphere. The aim of this study is, therefore, to find the origin of these mesospheric SPWs in the midwinter 2015/2016 study period. The study duration is split into two periods: the first period runs from late December 2015 until early January 2016 (Period I), and the second period from early January until mid-January 2016 (Period II). While the SPW 1 dominates in the subtropical mesosphere in Period I, it is the SPW 2 that dominates in Period II. There are three possibilities explaining how SPWs can occur in the mesosphere: (1) they propagate upward from the stratosphere, (2) they are generated in situ by longitudinally variable gravity wave (GW) drag, or (3) they are generated in situ by barotropic and/or baroclinic instabilities. Using global satellite observations from the Microwave Limb Sounder (MLS) and the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) the origin of the mesospheric SPWs is investigated for both time periods. We find that due to the strong PNJ the SPWs were not able to propagate upward into the mesosphere northward of 50∘ N but were deflected upward and equatorward into the subtropical mesosphere. We show that the SPWs observed in the subtropical mesosphere are the same SPWs as in the mid-latitudinal stratosphere. Simultaneously, we find evidence that the mesospheric SPWs in polar latitudes were generated in situ by longitudinally variable GW drag and that there is a mixture of in situ generation by longitudinally variable GW drag and by instabilities at mid-latitudes. Our results, based on observations, show that the abovementioned three mechanisms can act at the same time which confirms earlier model studies. Additionally, the possible contribution from, or impact of, unusually strong SPWs in the subtropical mesosphere to the disruption of the quasi-biennial oscillation (QBO) in the same winter is discussed.
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2

Flury, T., S. C. Müller, K. Hocke e N. Kämpfer. "Water vapor transport in the lower mesosphere of the subtropics: a trajectory analysis". Atmospheric Chemistry and Physics 8, n. 23 (10 dicembre 2008): 7273–80. http://dx.doi.org/10.5194/acp-8-7273-2008.

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Abstract. The Institute of Applied Physics operates an airborne microwave radiometer AMSOS that measures the rotational transition line of water vapor at 183.3 GHz. Water vapor profiles are retrieved for the altitude range from 15 to 75 km along the flight track. We report on a water vapor enhancement in the lower mesosphere above India and the Arabian Sea. The measurements took place on our flight from Switzerland to Australia and back in November 2005 conducted during EC- project SCOUT-O3. We find an enhancement of up to 25% in the lower mesospheric H2O volume mixing ratio measured on the return flight one week after the outward flight. The origin of the air is traced back by means of a trajectory model in the lower mesosphere and wind fields from ECMWF. During the outward flight the air came from the Atlantic Ocean around 25 N and 40 W. On the return flight the air came from northern India and Nepal around 25 N and 90 E. Mesospheric H2O measurements from Aura/MLS confirm the transport processes of H2O derived by trajectory analysis of the AMSOS data. Thus the large variability of H2O VMR during our flight is explained by a change of the winds in the lower mesosphere. This study shows that trajectory analysis can be applied in the mesosphere and is a powerful tool to understand the large variability in mesospheric H2O.
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3

Wallis, Sandra, Christoph Gregor Hoffmann e Christian von Savigny. "Estimating the impact of the 1991 Pinatubo eruption on mesospheric temperature by analyzing HALOE (UARS) temperature data". Annales Geophysicae 40, n. 3 (23 giugno 2022): 421–31. http://dx.doi.org/10.5194/angeo-40-421-2022.

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Abstract. The Mt. Pinatubo eruption in 1991 had a severe impact on the Earth system, with a well-documented warming of the tropical lower stratosphere and a general cooling of the surface. This study focuses on the impact of this event on the mesosphere by analyzing solar occultation temperature data from the Halogen Occultation Experiment (HALOE) instrument on the Upper Atmosphere Research Satellite (UARS). Previous analyses of lidar temperature data found positive temperature anomalies of up to 12.9 K in the upper mesosphere that peaked in 1993 and were attributed to the Pinatubo eruption. Fitting the HALOE data according to a previously published method indicates a maximum warming of the mesosphere region of 4.1 ± 1.4 K and does not confirm significantly higher values reported for that lidar time series. An alternative fit is proposed that assumes a more rapid response of the mesosphere to the volcanic event and approximates the signature of the Pinatubo with an exponential decay function having an e-folding time of 6 months. It suggests a maximum warming of 5.4 ± 3.0 K, if the mesospheric perturbation is assumed to reach its peak 4 months after the eruption. We conclude that the HALOE time series probably captures the decay of a Pinatubo-induced mesospheric warming at the beginning of its measurement period.
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4

Shi, Yu, Oleksandr Evtushevsky, Valerii Shulga, Gennadi Milinevsky, Andrew Klekociuk, Yulia Andrienko e Wei Han. "Mid-Latitude Mesospheric Zonal Wave 1 and Wave 2 in Recent Boreal Winters". Remote Sensing 13, n. 18 (18 settembre 2021): 3749. http://dx.doi.org/10.3390/rs13183749.

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Abstract (sommario):
Planetary waves in the mesosphere are studied using observational data and models to establish their origin, as there are indications of their generation independently of waves in the stratosphere. The quantitative relationships between zonal wave 1 and wave 2 were studied with a focus on the mid-latitude mesosphere at 50°N latitude. Aura Microwave Limb Sounder measurements were used to estimate wave amplitudes in geopotential height during sudden stratospheric warmings in recent boreal winters. The moving correlation between the wave amplitudes shows that, in comparison with the anticorrelation in the stratosphere, wave 2 positively correlates with wave 1 and propagates ahead of it in the mesosphere. A positive correlation r = 0.5–0.6, statistically significant at the 95% confidence level, is observed at 1–5-day time lag and in the 75–91 km altitude range, which is the upper mesosphere–mesopause region. Wavelet analysis shows a clear 8-day period in waves 1 and 2 in the mesosphere at 0.01 hPa (80 km), while in the stratosphere–lower mesosphere, the period is twice as long at 16 days; this is statistically significant only in wave 2. Possible sources of mesospheric planetary waves associated with zonal flow instabilities and breaking or dissipation of gravity waves are discussed.
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5

Zülicke, Christoph, Erich Becker, Vivien Matthias, Dieter H. W. Peters, Hauke Schmidt, Han-Li Liu, Laura de la Torre Ramos e Daniel M. Mitchell. "Coupling of Stratospheric Warmings with Mesospheric Coolings in Observations and Simulations". Journal of Climate 31, n. 3 (19 gennaio 2018): 1107–33. http://dx.doi.org/10.1175/jcli-d-17-0047.1.

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Abstract The vertical coupling between the stratosphere and the mesosphere is diagnosed from polar cap temperatures averaged over 60°–90°N with a new method: the joint occurrence of a warm stratosphere at 10 hPa and a cold mesosphere at 0.01 hPa. The investigation of an 11-yr-long dataset (2004–15) from Aura-MLS observations shows that such mesospheric coupling days appear in 7% of the winter. During major sudden stratospheric warming events mesospheric couplings are present with an enhanced average daily frequency of 22%. This daily frequency changes from event to event but broadly results in five of seven major warmings being classified as mesospheric couplings (2006, 2008, 2009, 2010, and 2013). The observed fraction of mesospheric coupling events (71%) is compared with simulations of the Kühlungsborn Mechanistic Circulation Model (KMCM), the Hamburg Model of the Neutral and Ionized Atmosphere (HAMMONIA), and the Whole Atmosphere Community Climate Model (WACCM). The simulated fraction of mesospheric coupling events ranges between 57% and 94%, which fits the observations. In searching for causal relations weak evidence is found that major warming events with strong intensity or split vortices favor their coupling with the upper mesosphere. More evidence is found with a conceptual model: an effective vertical coupling between 10 and 0.01 hPa is provided by deep zonal-mean easterlies at 60°N, which are acting as a gravity-wave guide. The explained variance is above 40% in the four datasets, which indicates a near-realistic simulation of this process.
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6

Hoppel, Karl W., Stephen D. Eckermann, Lawrence Coy, Gerald E. Nedoluha, Douglas R. Allen, Steven D. Swadley e Nancy L. Baker. "Evaluation of SSMIS Upper Atmosphere Sounding Channels for High-Altitude Data Assimilation". Monthly Weather Review 141, n. 10 (25 settembre 2013): 3314–30. http://dx.doi.org/10.1175/mwr-d-13-00003.1.

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Abstract Upper atmosphere sounding (UAS) channels of the Special Sensor Microwave Imager/Sounder (SSMIS) were assimilated using a high-altitude version of the Navy Global Environmental Model (NAVGEM) in order to investigate their potential for operational forecasting from the surface to the mesospause. UAS radiances were assimilated into NAVGEM using the new Community Radiative Transfer Model (CRTM) that accounts for Zeeman line splitting by geomagnetic fields. UAS radiance data from April 2010 to March 2011 are shown to be in good agreement with coincident temperature measurements from the Sounding of the Atmosphere Using Broadband Emission Radiometry (SABER) instrument that were used to simulate UAS brightness temperatures. Four NAVGEM experiments were performed during July 2010 that assimilated (i) no mesospheric observations, (ii) UAS data only, (iii) SABER and Microwave Limb Sounder (MLS) mesospheric temperatures only, and (iv) SABER, MLS, and UAS data. Zonal mean temperatures and observation − forecast differences for the UAS-only and SABER+MLS experiments are similar throughout most of the mesosphere, and show large improvements over the experiment assimilating no mesospheric observations, proving that assimilation of UAS radiances can provide a reliable large-scale constraint throughout the mesosphere for operational, high-altitude analysis. This is confirmed by comparison of solar migrating tides and the quasi-two-day wave in the mesospheric analyses. The UAS-only experiment produces realistic tidal and two-day wave amplitudes in the summer mesosphere in agreement with the experiments assimilating MLS and SABER observations, whereas the experiment with no mesospheric observations produces excessively strong mesospheric winds and two-day wave amplitudes.
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7

Sasi, M. N., e L. Vijayan. "Turbulence characteristics in the tropical mesosphere as obtained by MST radar at Gadanki (13.5° N, 79.2° E)". Annales Geophysicae 19, n. 8 (31 agosto 2001): 1019–25. http://dx.doi.org/10.5194/angeo-19-1019-2001.

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Abstract. Turbulent kinetic energy dissipation rates (ε) and eddy diffusion coefficients (Kz) in the tropical mesosphere over Gadanki (13.5° N, 79.2° E), estimated from Doppler widths of MST radar echoes (vertical beam), observed over a 3-year period, show a seasonal variation with a dominant summer maximum. The observed seasonal variation of ε and Kz in the mesosphere is only partially consistent with that of gravity wave activity inferred from mesospheric winds and temperatures measured by rockets for a period of 9 years at Trivandrum (8.5° N, 77° E) (which shows two equinox and one summer maxima) lying close to Gadanki. The summer maximum of mesospheric ε and Kz values appears to be related to the enhanced gravity wave activity over the low-latitude Indian subcontinent during the southwest monsoon period (June – September). Both ε and Kz in the mesosphere over Gadanki show an increase with an increase in height during all seasons. The absolute values of observed ε and Kz in the mesosphere (above ~80 km) does not show significant differences from those reported for high latitudes. Comparison of observed Kz values during the winter above Gadanki with those over Arecibo (18.5° N, 66° W) shows that they are not significantly different from each other above the ~80 km altitude.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; tropical meteorology; wave and tides)
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8

Kuilman, Maartje Sanne, e Bodil Karlsson. "The role of the winter residual circulation in the summer mesopause regions in WACCM". Atmospheric Chemistry and Physics 18, n. 6 (28 marzo 2018): 4217–28. http://dx.doi.org/10.5194/acp-18-4217-2018.

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Abstract. High winter planetary wave activity warms the summer polar mesopause via a link between the two hemispheres. Complex wave–mean-flow interactions take place on a global scale, involving sharpening and weakening of the summer zonal flow. Changes in the wind shear occasionally generate flow instabilities. Additionally, an altering zonal wind modifies the breaking of vertically propagating gravity waves. A crucial component for changes in the summer zonal flow is the equatorial temperature, as it modifies latitudinal gradients. Since several mechanisms drive variability in the summer zonal flow, it can be hard to distinguish which one is dominant. In the mechanism coined interhemispheric coupling, the mesospheric zonal flow is suggested to be a key player for how the summer polar mesosphere responds to planetary wave activity in the winter hemisphere. We here use the Whole Atmosphere Community Climate Model (WACCM) to investigate the role of the summer stratosphere in shaping the conditions of the summer polar mesosphere. Using composite analyses, we show that in the absence of an anomalous summer mesospheric temperature gradient between the equator and the polar region, weak planetary wave forcing in the winter would lead to a warming of the summer mesosphere region instead of a cooling, and vice versa. This is opposing the temperature signal of the interhemispheric coupling that takes place in the mesosphere, in which a cold and calm winter stratosphere goes together with a cold summer mesopause. We hereby strengthen the evidence that the variability in the summer mesopause region is mainly driven by changes in the summer mesosphere rather than in the summer stratosphere.
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9

Sandford, D. J., M. J. Schwartz e N. J. Mitchell. "The wintertime two-day wave in the Polar Stratosphere, Mesosphere and lower Thermosphere". Atmospheric Chemistry and Physics Discussions 7, n. 5 (16 ottobre 2007): 14747–65. http://dx.doi.org/10.5194/acpd-7-14747-2007.

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Abstract. Recent observations of the polar mesosphere have revealed that waves with periods near two days reach significant amplitudes in both summer and winter. This is in striking contrast to mid-latitude observations where two-day waves maximise in summer only. Here, we use data from a meteor radar at Esrange (68° N, 21° E) in the Arctic and data from the MLS instrument aboard the EOS Aura satellite to investigate the wintertime polar two-day wave in the stratosphere, mesosphere and lower thermosphere. The radar data reveal that mesospheric two-day wave activity measured by horizontal-wind variance has a semi-annual cycle with maxima in winter and summer and equinoctial minima. The MLS data reveal that the summertime wave in the mesosphere is dominated by a westward-travelling zonal wavenumber three wave with significant westward wavenumber four present. It reaches largest amplitudes at mid-latitudes in the southern hemisphere. In the winter polar mesosphere, however, the wave appears to be an eastward-travelling zonal wavenumber two, which is not seen during the summer. At the latitude of Esrange, the eastward-two wave reaches maximum amplitudes near the stratopause and appears related to similar waves previously observed in the polar stratosphere. We conclude that the wintertime polar two-day wave is the mesospheric manifestation of an eastward-propagating, zonal-wavenumber-two wave originating in the stratosphere, maximising at the stratopause and likely to be generated by instabilities in the polar night jet.
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Sandford, D. J., M. J. Schwartz e N. J. Mitchell. "The wintertime two-day wave in the polar stratosphere, mesosphere and lower thermosphere". Atmospheric Chemistry and Physics 8, n. 3 (13 febbraio 2008): 749–55. http://dx.doi.org/10.5194/acp-8-749-2008.

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Abstract (sommario):
Abstract. Recent observations of the polar mesosphere have revealed that waves with periods near two days reach significant amplitudes in both summer and winter. This is in striking contrast to mid-latitude observations where two-day waves maximise in summer only. Here, we use data from a meteor radar at Esrange (68° N, 21° E) in the Arctic and data from the MLS instrument aboard the EOS Aura satellite to investigate the wintertime polar two-day wave in the stratosphere, mesosphere and lower thermosphere. The radar data reveal that mesospheric two-day wave activity measured by horizontal-wind variance has a semi-annual cycle with maxima in winter and summer and equinoctial minima. The MLS data reveal that the summertime wave in the mesosphere is dominated by a westward-travelling zonal wavenumber three wave with significant westward wavenumber four present. It reaches largest amplitudes at mid-latitudes in the southern hemisphere. In the winter polar mesosphere, however, the wave appears to be an eastward-travelling zonal wavenumber two, which is not seen during the summer. At the latitude of Esrange, the eastward-two wave reaches maximum amplitudes near the stratopause and appears related to similar waves previously observed in the polar stratosphere. We conclude that the wintertime polar two-day wave is the mesospheric manifestation of an eastward-propagating, zonal-wavenumber-two wave originating in the stratosphere, maximising at the stratopause and likely to be generated by instabilities in the polar night jet.
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Tesi sul tema "Mesosphere"

1

MacLeod, R. I. "Dynamics of the Antarctic mesosphere /". Title page, contents and summary only, 1986. http://web4.library.adelaide.edu.au/theses/09PH/09phm1658.pdf.

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2

Lange, Martin, e Christoph Jacobi. "Einfluß des winterlichen stratosphärischen Polarwirbels auf die zonale Symmetrie des Windfeldes in der oberen Mesosphäre und unteren Thermosphäre simuliert mit dem COMMA-Modell". Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-216894.

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Langzeitmessungen des Windfeldes in der Mesopausenregion (~ 92km) an verschiedenen Stationen in den mittleren Breiten der Nordhemisphäre zeigen systematische zonale Variationen beim (zeitlich) gemittelten Zonal- und Meridionalwind und bei den Amplituden und Phasen der halbtägigen Gezeiten. Als eines der herausragenden Muster, die zonale Variationen in der unteren mittleren Atmosphäre anregen, wird der Einfluß der Geopotentialstörungen zur zonalen Wellenzahl 1 und 2, die mit dem winterlichen stratosphärischen Polarwirbel verbunden sind, auf das Windfeld in der oberen Mesosphäre / unteren Thermosphäre numerisch mit dem COMMA-Modell der mittleren Atmosphäre untersucht. Die Modellergebnisse zeigen eine gute Übereinstimmung der zonalen Variationen des mittleren Zonalwindes, die im Breitenbereich 52ÆN bis 56ÆN beobachtet werden und in der Größenordnung von 10 - 20 m/s liegen. Auch die halbtägigen Gezeitenamplituden und -phasen zeigen qualitative und quantitative Übereinstimmungen zwischen Beobachtungen und Modellergebnissen
Long-term time series of wind field observations in the upper mesosphere / lower thermosphere region at different locations in the midlatitude region indicate longitudinal variability in the (time-) mean zonal and meridional wind and in the amplitudes and phases of the semidiurnal tide, too. Being one of the prominent patterns forcing zonal inhomogenities in the lower middle atmosphere, the influence of the zonal wavenumber 1 and wavenumber 2 disturbances connected with the winter Northern Hemisphere stratospheric polar vortex on the mesosphere- / lower thermosphere wind field is numerically investigated with the COMMA model. The model results show that the zonal variations through the stationary waves coincide with typical observed mean zonal wind differences between different stations along the midlatitude belt between 52ÆN and 56ÆN with values about 10- 20 m/s. Also, the amplitude and phase variations of the semidiurnal tide show qualitative and quantitative agreements between model results and observations
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3

Jacobi, Christoph, e Peter Braesicke. "Correlation between stratosphere and upper mesosphere". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-214575.

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Collm mesopause winds are analysed with respect to their correlation with 30 hPa northern hemispheric stratospheric winds and pressure level heights. Correlation maps, based on the period of December 1978 through November 1997, are presented for each month of the year, showing possible connections between the lower and upper middle atmosphere, partly owing to the 10-12-year oscillation (TTO). Although in winter due to the propagation of planetary waves into the mesosphere direct coupling between the different layers of the atmosphere especially during stratospheric warmings is possible, the strongest correlation between stratosphere and mesopause region is found in summer, which is for the most part connected with the solar cycle dependence of the middle atmosphere
Die Mesopausenwinddaten vom Collm werden in Bezug auf ihre Verbindung mit stratosphärischen Winden und Druckhöhen in 30 hPa untersucht. Abbildungen der Korrelationskoeffizienten, basierend auf dem Zeitraum von Dezember 1978 bis November 1997 zeigen mögliche Verbindungen zwischen Stratosphäre und Mesopausenregion, zum Teil über die 10-12-jährige Schwingung (TTO) der Stratosphäre. Obwohl im Winter wegen der Ausbreitung planetarer Wellen in die Mesosphäre speziell während rascher Stratosphärenerwärmungen eine direkte Verbindung zwischen den Schichten der Atmosphäre auftritt, werden die stärksten Korrelationen im Sommer gefunden, größtenteils durch den Einfluß der TTO
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Jacobi, Christoph, Nadja Samtleben e Gunter Stober. "Meteor radar observations of mesopause region long-period temperature oscillations". Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-212263.

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Meteor radar observations of mesosphere/lower thermosphere (MLT) daily temperatures have been performed at Collm, Germany since August 2004. The data have been analyzed with respect to long-period oscillations at time scales of 2–30 days. The results reveal that oscillations with periods of up to 6 days are more frequently observed during summer, while those with longer periods have larger amplitudes during winter. The oscillations may be considered as the signature of planetary waves. The results are compared with analyses from radar wind measurements. Moreover, the temperature oscillations show considerable year-to-year variability. In particular, amplitudes of the quasi 5-day oscillation have increased during the last decade, and the quasi 10-day oscillations are larger if the equatorial stratospheric winds are eastward.
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Moss, Andrew. "Wave dynamics of the stratosphere and mesosphere". Thesis, University of Bath, 2017. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.707571.

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Gravity waves play a fundamental role in driving the large-scale circulation of the atmosphere. They are influenced both by the variation in their sources and the filtering effects of the winds they encounter as they ascend through the atmosphere. In this thesis we present new evidence that gravity waves play a key role in coupling the troposphere, stratosphere and mesosphere. In particular, we examine the connection of gravity waves to two important large-scale oscillations that occur in the atmosphere, namely the Madden-Julian Oscillation (MJO) in the troposphere and the Mesospheric Semi-Annual Oscillation (MSAO). We present the first ever demonstration that the MJO acts to modulate the global field of gravity waves ascending into the tropical stratosphere. We discover a significant correlation with the MJO zonal-wind anomalies and so suggest that the MJO modulates the stratospheric gravity-wave field through a critical-level wave-filtering mechanism. Strong evidence for this mechanism is provided by consideration of the winds encountered by ascending waves. The Ascension Island meteor radar is used for the first time to measure momentum fluxes over the Island. These measurements are then used to investigate the role of gravity-wave in driving a dramatic and anomalous wind event that was observed to occur during the first westward phase of the MSAO in 2002. Gravity waves are shown to play an important role in driving this event, but the observations presented here also suggest that the current theory of the mechanism describing these anomalous mesospheric wind events is not valid. Both of these studies highlight the critical importance of gravity waves to the dynamics of the atmosphere and highlight the need for further work to truly understand these waves, their processes and their variability.
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Beldon, Charlotte. "VHF radar studies of mesosphere and thermosphere". Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512294.

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Sandford, David J. "Dynamics of the stratosphere, mesosphere and thermosphere". Thesis, University of Bath, 2008. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.512300.

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This thesis presents observations of the dynamical features of the stratosphere, mesosphere and lower thermosphere. These are made from various observational techniques and model comparisons. A focus of the work is the two-day wave at high latitudes in the MLT region. This has revealed significant wave amplitudes in both summer and winter. However, these waves are shown to have very different origins. Using satellite data, the summertime wave is found to be the classic quasi-two-day wave which maximises at mid-latitudes in the MLT region. The wintertime wave is found to be a mesospheric manifestation of an eastward-propagating wave originating in the stratosphere and likely generated by barotropic and baroclinic instabilities in the polar night jet. The horizontal winds from Meteor and MF radars have been used to measure and produce climatologies of the Lunar M2 tide at Esrange in the Arctic (68°N), Rothera and Davis in the Antarctic (68°S), Castle Eaton at mid-latitude (52°N) and Ascension Island at Equatorial latitudes (8°S). These observations present the longest period of lunar semi-diurnal tidal observations in the MLT region to date, with a 16-year dataset from the UK meteor radar. Comparisons with the Vial and Forbes (1994) lunar tidal model are also made which reveal generally good agreement. Non-migrating lunar tides have been investigated. This uses lunar tidal results from equatorial stations, including the Ascension Island (8°S) meteor radar. Also lunar tidal results from the Rothera meteor wind radar (68°S, 68°W) and the Davis MF radar (68°S, 78°E) are considered. Both of these stations are on the edge of the Antarctic continent. It is demonstrated that there are often consistent tidal phase offsets between similar latitude stations. This suggests that non-migrating modes are likely to be present in the lunar semi-diurnal tidal structure and have significant amplitudes.
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Holt, Gavin. "Planetary waves in the stratosphere and mesosphere". Thesis, University of Oxford, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318787.

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9

Greet, P. A. "Observations on the sodium airglow /". Title page, contents and abstract only, 1988. http://web4.library.adelaide.edu.au/theses/09PH/09phg8166.pdf.

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10

Phillips, A. "Dynamics of the Antarctic mesosphere and lower thermosphere /". Title page, contents and abstract only, 1989. http://web4.library.adelaide.edu.au/theses/09PH/09php5583.pdf.

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Abstract (sommario):
Thesis (Ph. D.)--University of Adelaide, Mawson Institute for Antarctic Research, 1990.
Copies of author's previously published articles inserted. Includes bibliographical references (leaves 219-226).
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Libri sul tema "Mesosphere"

1

W, Rusch David, e United States. National Aeronautics and Space Administration., a cura di. An analysis of solar mesospheric temperatures for the upper stratosphere and mesosphere. [Washington, DC: National Aeronautics and Space Administration, 1993.

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2

J, Liebe H., e United States. National Telecommunications and Information Administration., a cura di. Millimeter-wave propogation in the mesosphere. Boulder, Colo: U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1989.

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3

J, Liebe H., e United States. National Telecommunications and Information Administration, a cura di. Millimeter-wave propogation in the mesosphere. Boulder, Colo: U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1989.

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4

J, Liebe H., e United States. National Telecommunications and Information Administration, a cura di. Millimeter-wave propogation in the mesosphere. Boulder, Colo: U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1989.

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5

J, Liebe H., e United States. National Telecommunications and Information Administration., a cura di. Millimeter-wave propagation in the mesosphere. Boulder, Colo: U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1989.

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J, Liebe H., e United States. National Telecommunications and Information Administration, a cura di. Millimeter-wave propagation in the mesosphere. Boulder, Colo: U.S. Dept. of Commerce, National Telecommunications and Information Administration, 1989.

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7

Burns, Alan. Data analysis and theoretical studies of the upper mesosphere and lower thermosphere. Ann Arbor, Mich: Space Physics Research Laboratory, 1994.

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8

United States. National Aeronautics and Space Administration., a cura di. Data analysis and theoretical studies of the upper mesosphere and lower thermosphere. Ann Arbor, Mich: Space Physics Research Laboratory, 1994.

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9

Rapp, Markus. Small scale processes in the mesosphere/lower thermosphere region. Oxford: Published for the Committee on Space Research [by] Elsevier, 2007.

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COSPAR. Scientific Commission C. C1.1 Symposia. Ionospheric/thermospheric/mesospheric coupling: Proceedings of the C1.1 and C1.2 Symposia of COSPAR Scientific Commission C which was held during the thirty-second COSPAR Scientific Assembly, Nagoya, Japan, 12-19 July 1998. Oxford: Published for the Committee on Space Research [by] Pergamon, 1999.

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Capitoli di libri sul tema "Mesosphere"

1

Lebonnois, Sébastien. "Mesosphere". In Encyclopedia of Astrobiology, 1. Berlin, Heidelberg: Springer Berlin Heidelberg, 2021. http://dx.doi.org/10.1007/978-3-642-27833-4_5485-1.

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Lebonnois, Sébastien. "Mesosphere". In Encyclopedia of Astrobiology, 1856. Berlin, Heidelberg: Springer Berlin Heidelberg, 2023. http://dx.doi.org/10.1007/978-3-662-65093-6_5485.

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Livesey, Nathaniel. "Trace Gases, Stratosphere, and Mesosphere". In Encyclopedia of Remote Sensing, 834–38. New York, NY: Springer New York, 2014. http://dx.doi.org/10.1007/978-0-387-36699-9_181.

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Roble, Raymond G. "Energetics of the Mesosphere and Thermosphere". In The Upper Mesosphere and Lower Thermosphere: A Review of Experiment and Theory, 1–21. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/gm087p0001.

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Vincent, R. A. "Low Frequency Dynamics of the Equatorial Mesosphere". In Coupling Processes in the Lower and Middle Atmosphere, 125–36. Dordrecht: Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1594-0_8.

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Norton, W. A., e J. Thuburn. "The Mesosphere in the Extended UGAMP GCM". In Gravity Wave Processes, 383–401. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60654-0_26.

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Lean, J. L. "Calculations of Lyman Alpha Absorption in the Mesosphere". In Atmospheric Ozone, 697–701. Dordrecht: Springer Netherlands, 1985. http://dx.doi.org/10.1007/978-94-009-5313-0_137.

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Vincent, R. A. "Radar Observations of Gravity Waves in the Mesosphere". In Transport Processes in the Middle Atmosphere, 47–56. Dordrecht: Springer Netherlands, 1987. http://dx.doi.org/10.1007/978-94-009-3973-8_4.

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Sica, R. J., e M. D. Thorsley. "Measurements of Intermittency in the Upper Stratosphere and Mesosphere". In Gravity Wave Processes, 27–44. Berlin, Heidelberg: Springer Berlin Heidelberg, 1997. http://dx.doi.org/10.1007/978-3-642-60654-0_3.

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Marsh, Daniel R. "Chemical–Dynamical Coupling in the Mesosphere and Lower Thermosphere". In Aeronomy of the Earth's Atmosphere and Ionosphere, 3–17. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0326-1_1.

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Atti di convegni sul tema "Mesosphere"

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Kreiss, William, Duc Kieu e Alex Stogryn. "Satellite microwave mesospheric temperature soundings - Mapping the mesosphere". In Space Programs and Technologies Conference. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1995. http://dx.doi.org/10.2514/6.1995-3779.

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Telle, John M. "Exploring High Altitude Beacon Concepts Other Than Sodium". In Adaptive Optics. Washington, D.C.: Optica Publishing Group, 1996. http://dx.doi.org/10.1364/adop.1996.amc.4.

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Na and most other mesospheric species suffer from two major shortcomings, low density and low saturation intensity. The Na density in the mesosphere is typically 103 - 104 atoms per cm3. Moreover this density is spread over about 100 velocity classes with a natural width of 10 MHz giving a total Doppler width of 1 GHz for each line. The D2 line is split by 1.772 GHz into a doublet ignoring other hyperfine splittings of the order of 10 MHz. The doublet is often treated as a single line with 3 GHz FWHM. The Doppler-broadened Na cross section is about 2.7 (-12) cm2 but the low density results in only about 1.5% unsaturated absorption across the entire mesosphere (depth ≈ 10 km).
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Taylor, FW. "Remote Sensing of Atmospheric Structure and Composition by Pressure Modulator Radiometry from Space: The ISAMS Experiment on UARS". In Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/orsa.1990.ma2.

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This paper describes the Improved Stratospheric and Mesospheric Sounder experiment on the Upper Atmosphere Research Satellite. ISAMS uses a technique called pressure modulator radiometry, which permits the measurement of selected atmospheric parameters with high precision and selectivity. Marriage of this technique with the objectives of the UARS programme is aimed at producing a radical improvement in current knowledge of the middle atmosphere. In particular, it is hoped to make significant progress in understanding the coupled behaviour of radiation, dynamics and photochemistry in the stratosphere and mesosphere.
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Morris, P. E., F. W. Taylor e J. Ballard. "Spectral Calibration of the Improved Stratospheric and Mesospheric Sounder". In Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1993. http://dx.doi.org/10.1364/orsa.1993.pd.10.

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The Improved Stratospheric and Mesospheric Sounder (ISAMS) is a limb-viewing infrared radiometer which measures thermal emission in 24 spectral bands, using both wideband (WB) and pressure modulator radiometer (PMR) techniques (Taylor, 1983). This enables the daily mapping over much of the Earth of temperature, the concentrations of 8 chemical species (water vapour, methane, ozone, nitric acid, nitrogen dioxide, nitric oxide, dinitrogen pentoxide, carbon monoxide) and aerosol opacity in the stratosphere and mesosphere. The instrument has eight separate focal planes, each consisting of a 4-element detector array, which are cooled by two mechanical coolers.
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López-Valverde, M. A., M. López-Puertas e C. J. Marks. "Non-LTE Modelling for the Retrieval of CO Abundances from ISAMS Measurements". In Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/orsa.1991.omb5.

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The study of CO in the terrestrial middle atmosphere is of considerable interest since it plays an important role in many photochemical processes involving species like OH and O3. It can also be a very good tracer, especially in the mesosphere where its photochemical lifetime becomes longer1,2. Its volume mixing ratio is very variable in altitude, latitude and time3 because of the variety of production and loss mechanisms. ISAMS is the only instrument on board UARS which measures CO atmospheric emission at 4.7 μm. This emission originates from the first vibrationally excited level of the CO molecule which is in non-LTE in the whole mesosphere4,5,6. Also the increase with height of the concentration of CO in the mesosphere gives rise to the important contribution of mesospheric levels to limb radiances at stratospheric tangent heights. Therefore, knowledge of the non-LTE source function is essential before CO abundances in the middle atmosphere can be retrieved from 4.7 limb radiances. We describe here the non-LTE model we have developed to compute the population of CO(1) and the way in which these calculations will be incorporated into the ISMAS retrieval scheme.
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Burka, Michael, Warren Moskowitz, Gilbert Davidson, John W. Meriwether, Capt Ross McNutt, Robert Farley e Phan Dao. "Rayleigh Lidar Measurements and Noctilucent Clouds". In Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/orsa.1991.otuc4.

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Noctilucent clouds (NLC) are ice clouds located in the high latitude summer mesosphere at heights between 81 and 85 km. The formation process is not well understood but it is thought that a growth cycle is activated by the extremely low temperatures of the mesopause region, typically 120 to 130 °K. This process involving condensation nuclei transported into the mesosphere from meteoritic debris and the upwelling of water vapor into the mesosphere from below produces condensation of ice upon particles within the supersaturated region lying several kilometers below the mesopause temperature minimum.
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Clancy, R. Todd, e David W. Rusch. "Global Middle Atmospheric (20-100 km) Temperatures Derived from Satellite Ultraviolet, Visible, and Near-Infrared Limb Profiles of Rayleigh Scattering". In Optical Remote Sensing of the Atmosphere. Washington, D.C.: Optica Publishing Group, 1991. http://dx.doi.org/10.1364/orsa.1991.otuc3.

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We describe a simple and accurate satellite-based technique for measuring temperatures throughout the Earth's middle atmosphere, based upon limb profile observations of Rayleigh scattered sunlight. An example of the precision and accuracy of this technique are two analyses limb radiances from the Solar Mesospheric Explorer, which provided a global climatology of temperatures in the poorly sampled mesospheric region from 60-90 km altitude (Clancy and Rusch, 1989); and more recently for the upper stratosphere (Clancy and Rusch, 1991). The SME mesospheric temperatures were derived from ultraviolet (265, 295 nm) limb radiances, which lead to optimum signal-to-noise ratios for measurement of Rayleigh scattering within the low density mesosphere. In figure 1, we reproduce (from Clancy and Rusch, 1989) a limited comparison of SME mesospheric temperatures with SAMS and French lidar observations (Chanin et al., 1987) at an altitude of 65 km and a latitude of 45°N. We also reproduce, in figure 2, the four-year (1982-1986) SME temperature trends for the 60-90 km altitude region.
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Norberg, Carol, Asta Pellinen-Wannberg, José Tito Mendonça, David P. Resendes e Padma K. Shukla. "Active Dust Experiment in the Mesosphere". In MULTIFACETS OF DUSTRY PLASMAS: Fifth International Conference on the Physics of Dusty Plasmas. AIP, 2008. http://dx.doi.org/10.1063/1.2997135.

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Garmash, K. P., A. I. Gritchin, S. I. Martynenko, V. T. Rozumenko e O. F. Tyrnov. "Electrodynamic processes in the electrically active mesosphere". In 2010 20th International Crimean Conference "Microwave & Telecommunication Technology" (CriMiCo 2010). IEEE, 2010. http://dx.doi.org/10.1109/crmico.2010.5632884.

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Torr, D. "Achievements in atmospheric science - The mesosphere/lower thermosphere". In 32nd Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1994. http://dx.doi.org/10.2514/6.1994-443.

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Rapporti di organizzazioni sul tema "Mesosphere"

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Verronen, P. T:, a cura di. 11 th International Workshop on Long-Term Changes and Trends in the Atmosphere, Book of Abstracts. Finnish Meteorological Institute, maggio 2022. http://dx.doi.org/10.35614/isbn.9789523361577.

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The 11 th International Workshop on Long-Term Changes and Trends in the Atmosphere will be held between 30 May and 3 June, 2022, at the Finnish Meteorological Institute in Helsinki, Finland. The workshop is organised by the Finnish Meteorological Institute. The workshop gathers together more than 50 scientists from the EU, USA, India, Canada, Argentina, Norway, China, Switzerland, and UK. This report is the official abstract book of the workshop. The scientific topics include: ● Stratospheric and mesospheric observations ● Simulations and predictions of the stratosphere and mesosphere ● Changes in the ionosphere and thermosphere ● Dynamic, physical, chemical and radiative mechanisms ● Role of the stratosphere and mesosphere for climate The workshop is sponsored by the International Association of Geomagnetism and Aeronomy (IAGA) and the International Association of Meteorology and Atmospheric Sciences (IAMAS).
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Roble, Raymond G. Thermosphere-Ionosphere-Mesosphere Modeling Using the TIME-GCM. Fort Belvoir, VA: Defense Technical Information Center, settembre 2003. http://dx.doi.org/10.21236/ada628807.

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Roble, Raymond G. Thermosphere-Ionosphere-Mesosphere Modeling Using the TIME-GCM. Fort Belvoir, VA: Defense Technical Information Center, settembre 2014. http://dx.doi.org/10.21236/ada623757.

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Lang, V. I. Relaxation Processes of Vibrationally Excited H2O in the Mesosphere and Thermosphere. Fort Belvoir, VA: Defense Technical Information Center, settembre 1991. http://dx.doi.org/10.21236/ada241853.

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Wintersteiner, Peter P., e Edward Cohen. Observations and Modeling of the Upper Mesosphere: Mesopause Characteristics, Inversion Layers, and Bores. Fort Belvoir, VA: Defense Technical Information Center, ottobre 2005. http://dx.doi.org/10.21236/ada447582.

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Palo, Scott E. A Low-Cost, Remotely-Deployable Meteor Radar System for Mesosphere/Ionosphere Coupling Studies. Fort Belvoir, VA: Defense Technical Information Center, aprile 2001. http://dx.doi.org/10.21236/ada387697.

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Hernandez, G. Investigations of the Dynamics and Thermodynamics of the Mesosphere and Upper Thermosphere at the Polar Regions. Fort Belvoir, VA: Defense Technical Information Center, giugno 1988. http://dx.doi.org/10.21236/ada198463.

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Kelley, Michael C. Application of and Enhancement to Arctic Infrastructure for the Study of Long-Term Change in the Earth's Polar Mesosphere. Fort Belvoir, VA: Defense Technical Information Center, aprile 2001. http://dx.doi.org/10.21236/ada385461.

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Meriwether, John W. Climatological Studies of Mesospheric and Lower Thermosphere Thermal and Neutral Wind Structure at Maui, Hawaii. Fort Belvoir, VA: Defense Technical Information Center, giugno 2005. http://dx.doi.org/10.21236/ada438584.

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Taylor, Michael J. Development of an Advanced OH Mesospheric Temperature Mapper for Correlative Dynamical Studies at the ALOMAR Arctic Observatory (69 degree N). Fort Belvoir, VA: Defense Technical Information Center, maggio 2005. http://dx.doi.org/10.21236/ada434569.

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