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Letteratura scientifica selezionata sul tema "Atmospheric tides"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 9 giugno 2025

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Articoli di riviste sul tema "Atmospheric tides"

1

Palumbo, A. "Atmospheric tides." Journal of Atmospheric and Solar-Terrestrial Physics 60, no. 3 (February 1998): 279–87. http://dx.doi.org/10.1016/s1364-6826(97)00078-3.

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2

Auclair-Desrotour, P., S. Mathis, and J. Laskar. "Atmospheric thermal tides and planetary spin." Astronomy & Astrophysics 609 (January 2018): A118. http://dx.doi.org/10.1051/0004-6361/201731540.

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Context. Thermal atmospheric tides can torque telluric planets away from spin-orbit synchronous rotation, as observed in the case of Venus. They thus participate in determining the possible climates and general circulations of the atmospheres of these planets. Aims. The thermal tidal torque exerted on an atmosphere depends on its internal structure and rotation and on the tidal frequency. Particularly, it strongly varies with the convective stability of the entropy stratification. This dependence has to be characterized to constrain and predict the rotational properties of observed telluric exoplanets. Moreover, it is necessary to validate the approximations used in global modelings such as the traditional approximation, which is used to obtain separable solutions for tidal waves. Methods. We wrote the equations governing the dynamics of thermal tides in a local vertically stratified section of a rotating planetary atmosphere by taking into account the effects of the complete Coriolis acceleration on tidal waves. This allowed us to analytically derive the tidal torque and the tidally dissipated energy, which we used to discuss the possible regimes of tidal dissipation and to examine the key role played by stratification. Results. In agreement with early studies, we find that the frequency dependence of the thermal atmospheric tidal torque in the vicinity of synchronization can be approximated by a Maxwell model. This behavior corresponds to weakly stably stratified or convective fluid layers, as observed previously. A strong stable stratification allows gravity waves to propagate, and makes the tidal torque negligible. The transition is continuous between these two regimes. The traditional approximation appears to be valid in thin atmospheres and in regimes where the rotation frequency is dominated by the forcing or the buoyancy frequencies. Conclusions. Depending on the stability of their atmospheres with respect to convection, observed exoplanets can be tidally driven toward synchronous or asynchronous final rotation rates. The domain of applicability of the traditional approximation is rigorously constrained by calculations.

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3

Auclair-Desrotour, P., J. Laskar, and S. Mathis. "Atmospheric tides in Earth-like planets." Astronomy & Astrophysics 603 (July 2017): A107. http://dx.doi.org/10.1051/0004-6361/201628252.

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Context. Atmospheric tides can strongly affect the rotational dynamics of planets. In the family of Earth-like planets, which includes Venus, this physical mechanism coupled with solid tides makes the angular velocity evolve over long timescales and determines the equilibrium configurations of their spin. Aims. Unlike the solid core, the atmosphere of a planet is subject to both tidal gravitational potential and insolation flux coming from the star. The complex response of the gas is intrinsically linked to its physical properties. This dependence has to be characterized and quantified for application to the wide variety of extrasolar planetary systems. Methods. We develop a theoretical global model where radiative losses, which are predominant in slowly rotating atmospheres, are taken into account. We analytically compute the perturbation of pressure, density, temperature, and velocity field caused by a thermogravitational tidal perturbation. From these quantities, we deduce the expressions of atmospheric Love numbers and tidal torque exerted on the fluid shell by the star. The equations are written for the general case of a thick envelope and the simplified one of a thin isothermal atmosphere. Results. The dynamics of atmospheric tides depends on the frequency regime of the tidal perturbation: the thermal regime near synchronization and the dynamical regime characterizing fast-rotating planets. Gravitational and thermal perturbations imply different responses of the fluid, i.e. gravitational tides and thermal tides, which are clearly identified. The dependence of the torque on the tidal frequency is quantified using the analytic expressions of the model for Earth-like and Venus-like exoplanets and is in good agreement with the results given by global climate models (GCM) simulations.Introducing dissipative processes such as radiation regularizes the tidal response of the atmosphere, otherwise it is singular at synchronization. Conclusions. We demonstrate the important role played by the physical and dynamical properties of a super-Earth atmosphere (e.g. Coriolis, stratification, basic pressure, density, temperature, radiative emission) in its response to a tidal perturbation. We point out the key parameters defining tidal regimes (e.g. inertia, Brunt-Väisälä, radiative frequencies, tidal frequency) and characterize the behaviour of the fluid shell in the dissipative regime, which cannot be studied without considering the radiative losses.

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4

Navarro, Thomas, Timothy M. Merlis, Nicolas B. Cowan, and Natalya Gomez. "Atmospheric Gravitational Tides of Earth-like Planets Orbiting Low-mass Stars." Planetary Science Journal 3, no. 7 (July 1, 2022): 162. http://dx.doi.org/10.3847/psj/ac76cd.

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Abstract Temperate terrestrial planets orbiting low-mass stars are subject to strong tidal forces. The effects of gravitational tides on the solid planet and that of atmospheric thermal tides have been studied, but the direct impact of gravitational tides on the atmosphere itself has so far been ignored. We first develop a simplified analytic theory of tides acting on the atmosphere of a planet. We then implement gravitational tides into a general circulation model of a static-ocean planet in a short-period orbit around a low-mass star—the results agree with our analytic theory. Because atmospheric tides and solid-body tides share a scaling with the semimajor axis, we show that there is a maximum amplitude of the atmospheric tide that a terrestrial planet can experience while still having a solid surface; Proxima Centauri b is the poster child for a planet that could be geophysically Earth-like but with atmospheric tides more than 500× stronger than Earth’s. In this most extreme scenario, we show that atmospheric tides significantly impact the planet’s meteorology—but not its climate. Two possible modest climate impacts are enhanced longitudinal heat transport and cooling of the lowest atmospheric layers. The strong radiative forcing of such planets dominates over gravitational tides, unlike moons of cold giant planets, such as Titan. We speculate that atmospheric tides could be climatologically important on planets where the altitude of maximal tidal forcing coincides with the altitude of cloud formation and that the effect could be detectable for non-Earth-like planets subject to even greater tides.

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5

Auclair-Desrotour, P., J. Laskar, and S. Mathis. "Atmospheric tides and their consequences on the rotational dynamics of terrestrial planets." EAS Publications Series 82 (2019): 81–90. http://dx.doi.org/10.1051/eas/1982008.

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Atmospheric tides can have a strong impact on the rotational dynamics of planets. They are of most importance for terrestrial planets located in the habitable zone of their host star, where their competition with solid tides is likely to drive the body towards non-synchronized rotation states of equilibrium, as observed in the case of Venus. Contrary to other planetary layers, the atmosphere is sensitive to both gravitational and thermal forcings, through a complex dynamical coupling involving the effects of Coriolis acceleration and characteristics of the atmospheric structure. These key physics are usually not taken into account in modelings used to compute the evolution of planetary systems, where tides are described with parametrised prescriptions. In this work, we present a new ab initio modeling of atmospheric tides adapting the theory of the Earth’s atmospheric tides (Chapman & Lindzen 1970) to other terrestrial planets. We derive analytic expressions of the tidal torque, as a function of the tidal frequency and parameters characterizing the internal structure (e.g. the Brunt-Väisälä frequency, the radiative frequency, the pressure heigh scale). We show that stratification plays a key role, the tidal torque being strong in the case of convective atmospheres (i.e. with a neutral stratification) and weak in case of atmosphere convectively stable. In a second step, the model is used to determine the non-synchronized rotation states of equilibrium of Venus-like planets as functions of the physical parameters of the system. These results are detailed in Auclair-Desrotour et al. (2016a) and Auclair-Desrotour et al. (2016b).

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6

Brahde, R. "Lunisolar Atmospheric Tides. II." Australian Journal of Physics 42, no. 4 (1989): 439. http://dx.doi.org/10.1071/ph890439.

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In an earlier paper (Brahde 1988) it was shown that series of measurements of the atmospheric pressure in Oslo contained information about a one�day oscillation with mean amplitude 0�17 mb. The data consisted of measurements every second hour during the years 1957-67, 1969 and 1977. In the present paper the intervening years plus 1978 and 1979 have been included, increasing the basis from 13 to 23 years. In addition the phase shift occurring when the Moon crosses the celestial equator has been defined precisely, thus making it possible to include all the data.

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Brahde, R. "Lunisolar Atmospheric Tides. III." Australian Journal of Physics 44, no. 1 (1991): 87. http://dx.doi.org/10.1071/ph910087.

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In two earlier papers (Brahde 1988, 1989) the atmospheric tide in Oslo (Norway) was studied using pressure data for 23 continuous years. In the present paper a similar study based on pressure data from Batavia (now Jakarta in Indonesia, latitude 6�08'S, longitude 106�45'E) is presented. The result is that the tidal wave caused by the lunisolar tide is represented by a one-day and a half-day oscillation with mean amplitudes of 0 �11 and 0�33 mb respectively. The amplitude spectrum reveals amplitudes of up to 1 mb of dynamiC origin. The 'thermal' tide is also studied and the connection between the thermal and dynamic effects is discussed.

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8

FORBES, Jeffrey M. "Middle Atmosphere Tides and Coupling between Atmospheric Regions." Journal of geomagnetism and geoelectricity 43, Supplement2 (1991): 597–609. http://dx.doi.org/10.5636/jgg.43.supplement2_597.

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9

Salazar, Andrea M., and Robin Wordsworth. "The Feasibility of Asynchronous Rotation via Thermal Tides for Diverse Atmospheric Compositions." Planetary Science Journal 5, no. 10 (October 1, 2024): 218. http://dx.doi.org/10.3847/psj/ad74ef.

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Abstract The equilibrium rotation rate of a planet is determined by the sum of torques acting on its solid body. For planets with atmospheres, the dominant torques are usually the gravitational tide, which acts to slow the planet’s rotation rate, and the atmospheric thermal tide, which acts to spin up the planet. Previous work demonstrated that rocky planets with thick atmospheres may produce strong enough thermal tides to avoid tidal locking, but a study of how the strength of the thermal tide depends on atmospheric properties has not been done. In this work, we use a combination of simulations from a global climate model and analytic theory to explore how the thermal tide depends on the shortwave and longwave optical depth of the atmosphere, the surface pressure, and the absorbed stellar radiation. We find that for planets in the habitable zones of M stars only high-pressure but low-opacity atmospheres permit asynchronous rotation owing to the weakening of the thermal tide at high longwave and shortwave optical depths. We conclude that asynchronous rotation may be very unlikely around low-mass stars, which may limit the potential habitability of planets around M stars.

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10

Biagi, P. F., R. Piccolo, V. Capozzi, A. Ermini, S. Martellucci, and C. Bellecci. "Exalting in atmospheric tides as earthquake precursor." Natural Hazards and Earth System Sciences 3, no. 3/4 (August 31, 2003): 197–201. http://dx.doi.org/10.5194/nhess-3-197-2003.

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Abstract. During February–March 1998, we observed a significant increase (6–8 dB) in the electric field of the CZE (f = 270 kHz, Czech Republic) broadcasting station at a site named AS and located in central Italy. On 13 March 1998 an earthquake (M = 5.2) occurred in Slovenia, starting a strong seismic crisis (M = 6.0 on 12 April, M = 5.1 on 6 May). The distances of the epicentres from the radio receiver were over 400 km, but the epicentres are located in a zone that is in the middle of the CZE-AS path. Previously, we advanced the hypothesis that the increase of radio-signal electric field detected could be a precursor of the Slovenia seismic crisis. At the purpose to precise the connection between this radio anomaly and the preparatory phase of the earthquakes, we analysed in detail the data collected. At first we carried out a FFT on the data and clear harmonic components with period 0.5d, 1d, 14d, 28d and 365d were revealed. These periods are characteristic of gravity tides and therefore, it seems reasonable to consider the previous harmonics in the electric field of the radio signal as components related to tides of the atmosphere, assuming as tides of the atmosphere only the linear action of gravity tides on atmosphere. Then, we carried out band pass filters on our data and we discovered that the February–March 1998 increase is mainly related to an exalting of the harmonics with period 0.5d, 1d, 14d and 28d, i.e. of the (semi)monthly and (semi)diurnal atmospheric tidal components in the radio signal. Supposing that this exalting is produced by a corresponding exalting of the atmospheric tides we propose a model able to explain the production of such an effect during the preparatory phase of the Slovenia earthquakes.

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Tesi sul tema "Atmospheric tides"

1

Oliver, Sophia. "Modelling studies of the atmospheric tides." Thesis, University of Oxford, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.365773.

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2

Kovalam, Sujata. "MF radar observations of tides and planetary waves." Title page, contents and abstract only, 2000. http://web4.library.adelaide.edu.au/theses/09PH/09phk878.pdf.

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Copies of previously published articles inserted. Bibliography: p. 185-200. Data obtained from six radar stations covering a wide latitude range has been used to determine the global distribution of planetary waves and tides. In the process a number of data analyses techniques were considered for their characterisation.

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3

Mertz, Gordon James. "Atmospheric and oceanic 40- to 50-day oscillations in the source region of the Somali Current." Thesis, University of British Columbia, 1985. http://hdl.handle.net/2429/25933.

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Current and temperature data were acquired in the source region of the Somali Current, jointly by the Universities of Kiel and Miami, as part of the INDEX pilot studies. The data were acquired over a six-month period (January-July, 1976) which spans the springtime Monsoon reversal. The experiment and the data are described in Düing and Schott (1978). This thesis describes the results of the spectrum analysis of fluctuations found in data from the experiment's two southernmost sensor locations. It is found that, once the annual cycle is removed, most of the variance in these current and temperature records resides in subinertial fluctuations. The most prominent spectral feature is a 40- to 50-day peak. This 40- to 50-day period is coincident with that of the global-scale circulation cells found in the tropical atmosphere by Madden and Julian (1971 and 1972). The analysis of wind stress and wind stress curl data for the years 1976 and 1979 presented in this thesis indicate that the 40-to 50-day oscillation was present over the Western Indian Ocean during these years. It is suggested here that wind-forcing excites a long coastally trapped wave. To test this idea, a wind-forced quasi-geostrophic, three-layer model and a reduced-gravity model incorporating lateral mean current shear are applied to the Somali Current regime. Model results suggest that the wind forcing is strong enough to excite the observed current and temperature fluctuations.<br>Science, Faculty of<br>Physics and Astronomy, Department of<br>Graduate

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4

Wood, Andrew Richard. "Theoretical studies of atmospheric tides for the interpretation of satellite data." Thesis, University of Oxford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359582.

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5

Yagai, Isamu. "NUMERICAL SIMULATION OF ATMOSPHERIC THERMAL TIDES WITH A GENERAL CIRCULATION MODEL." Kyoto University, 1991. http://hdl.handle.net/2433/168744.

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本文データは平成22年度国立国会図書館の学位論文(博士)のデジタル化実施により作成された画像ファイルを基にpdf変換したものである<br>Kyoto University (京都大学)<br>0048<br>新制・論文博士<br>博士(工学)<br>乙第7629号<br>論工博第2514号<br>新制||工||853(附属図書館)<br>UT51-91-T435<br>(主査)教授加藤進, 教授深尾昌一郎, 教授桜井健郎<br>学位規則第4条第2項該当

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6

Sridharan, S. "Investigation of middle atmospheric winds, waves and tides from low latitudes." Thesis, Indian Institute of Geomagnetism, Mumbai, 2002. http://localhost:8080/xmlui/handle/123456789/221.

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Sridharan, S. "Investigation of middle atmospheric winds, waves and tides from low latitudes." Thesis, IIG, 2002. http://localhost:8080/xmlui/handle/123456789/1604.

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A Thesis submitted to the Moanonmaniam Sundaranar University, Tirunelveli, in partial fulfilment of the requirements for the Ph.D. degree under the guidance of Dr. S. Gurubaran, Equatorial Geophysical Research Laboratory, Tirunelveli and Dr. N. Arunachalam, M.S. University, Tirunelveli

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8

Stine, Alexander 1973. "A survey of internal tides as seen in moored buoy records." Thesis, Massachusetts Institute of Technology, 2002. http://hdl.handle.net/1721.1/29579.

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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, June 2003.<br>Includes bibliographical references (leaves 139-144).<br>We estimate the vertical structure of tidal frequency energy at various locations in the ocean by decomposing current records from the WHOI moored buoy archive. Estimates are made of the barotropic and baroclinic modes 1-4 for multiple locations, primarily in the North Atlantic and North Pacific. Estimates are also made for energy flux rates at some locations. The implied global dissipation rate fro the internal tides is significantly below estimates from altimetry.<br>by Alexander Stine.<br>S.M.

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Baumgaertner, Andreas Josef Gerhard. "Observations of Middle Atmosphere Dynamics over Antarctica." Thesis, University of Canterbury. Physics and Astronomy, 2007. http://hdl.handle.net/10092/1397.

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This thesis is concerned with the dynamics of the middle atmosphere over the southern-most continent on our planet, Antarctica. Building on previous observational and theoretical efforts to understand the dynamics of this region of the atmosphere, the work encompasses instrument improvements as well as data analysis studies of gravity waves in the lower and middle stratosphere, tides in the upper mesosphere and lower thermosphere, and short-period planetary waves in the stratosphere and mesosphere. An upgrade of the Medium-Frequency Spaced Antenna (MFSA) radar at Scott Base, Antarctica, was carried out in 2004/5 in order to ensure continued operation and enhance its capabilities to measure gravity waves. As a result, the quality of the wind measurements was greatly enhanced and the amount of data collected is now greater by a factor of approximately 15 compared with before the upgrade. Analysis of over two decades of wind velocity data from Scott Base yields a reliable climatology of the dynamics of the upper mesosphere and lower thermosphere in this area, namely the tidal oscillations and the background winds. In addition, interannual variability is assessed and periodicities of approximately 11 years and strong positive trends in tidal amplitudes are reported. Mechanisms that could explain the observed behaviour are proposed. The data are then combined with wind measurements from Halley, the longitudinal conjugate site, in order to study the zonal character of the semi-diurnal tide. Zonal wavenumber 1 and 2 waves are both found and mechanisms that could explain the generation of a wavenumber 1 component are suggested. Two further sets of MFSA radar wind measurements are used to investigate the behaviour of planetary waves with periods of between two and four days in the Antarctic middle atmosphere. Satellite temperature measurements further help to create a more complete picture of these waves. Baroclinic and barotropic instabilities, which result from shears of the zonal wind, appear to be responsible for much of the observed wave activity. In addition, a quasi-to day wave event in mid-May 2005 with unusually large amplitudes is examined and suggested to be linked to a solar proton event. Gravity wave activity over Antarctica is studied using temperature profiles obtained through the satellite radio occultation technique. Although the measurements are restricted to below 35 km altitude, high-resolution temperature profiles allow conclusions to be drawn about the seasonal, geographical, and height distribution of gravity wave activity. Mountain waves are found to be important over the Antarctic Peninsula and the Transantarctic mountains where they contribute more than 20% of the observed wave activity in the lower stratosphere. In addition, the analysis indicates the importance of critical-level filtering and Doppler-shifting.

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Kim, Sungphil. "Internal Tides and Internal Solitary Waves in the Northern South China Sea." NCSU, 2009. http://www.lib.ncsu.edu/theses/available/etd-05152009-141246/.

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Large-amplitude internal solitary waves (ISWs) are frequently observed in the northern South China Sea (SCS). In a project sponsored by the US Office of Naval Research, four moorings were deployed between the Luzon Strait and the Chinese continental shelf by Steve Ramp of the Naval Postgraduate School and David Tang of National Taiwan University from late April 2005 to May 2006. Several CTD sections were taken during April and July in 2005. Satellite pictures were also collected during that period. In this study, these data were used to examine the characteristics, generation, and propagation of ISWs. In the satellite images, monthly change in stratification may cause northward shift of the propagation path, and ISWs are more frequently observed in July than in April and May. Speed estimation shows that ISWs propagate faster in the deep basin than over the continental margin and near the ridge. The generation of internal tides correlates with the eastward tidal flow over the ridge, while ISWs are produced by northwestward tidal currents over the ridges in the Luzon Strait.

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Più fonti

Libri sul tema "Atmospheric tides"

1

S, Lindzen Richard, ed. Atmospheric tides: Thermal and gravitational. New York: Gordon and Breach, 1987.

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2

John, Stanford. Oscillations in D-region absorption at periods of one to two months. [Washington, D.C: National Aeronautics and Space Administration, 1989.

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John, Stanford. Oscillations in D-region absorption at periods of one to two months. [Washington, D.C: National Aeronautics and Space Administration, 1989.

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4

Volland, Hans. Atmospheric tidal and planetary waves. Dordrecht: Kluwer Academic Publishers, 1988.

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Kähler, Malte. Thermische Gezeiten in einem dreidimensionalen Zirkulationsmodell. Berlin: D. Reimer, 1988.

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6

Kelder, H. On waves in the upper atmosphere. De Bilt: Koninklijk Nederlands Meteorologisch Instituut, 1986.

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7

Lambrecht, Michael. Numerische Untersuchungen zur tropischen 30-60 tägigen Oszillation mit einem konzeptionellen Modell. Bonn: Dümmler, 1996.

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8

Assembly, COSPAR Scientific. Atmospheric tidal dynamics and E- and D-region physics: Proceedings of the CO.1 and C4.1 Symposia of COSPAR Scientific Commission C which was held during the thirty-first COSPAR Scientific Assembly, Birmingham, U.K., 14-21 July 1996. Kidlington, Oxford: Published for the Committee on Space Research [by] Pergamon, 1998.

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9

Williams, Christopher Reed. Analysis of deep convective clouds and their association with non-migrating atmospheric diurnal tides in the tropical troposphere. Boulder, Colo: U.S. Dept. of Commerce, National Oceanic and Atmospheric Administration, Environmental Research Laboratories, Aeronomy Laboratory, 1994.

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United States. National Aeronautics and Space Administration., ed. An a priori model for the reduction of nutation observations: KSV₁₉₉₄ ̣₃ nutation series. [Washington, D.C: National Aeronautics and Space Administration, 1995.

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Capitoli di libri sul tema "Atmospheric tides"

1

Dieminger, Walter, Gerd K. Hartmann, and Reinhart Leitinger. "Atmospheric Tides." In The Upper Atmosphere, 97–109. Berlin, Heidelberg: Springer Berlin Heidelberg, 1996. http://dx.doi.org/10.1007/978-3-642-78717-1_3.

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Lindzen, Richard S. "Richard J. Reed and Atmospheric Tides." In A Half Century of Progress in Meteorology: A Tribute to Richard Reed, 85–89. Boston, MA: American Meteorological Society, 2003. http://dx.doi.org/10.1007/978-1-878220-69-1_6.

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3

Müller, Peter, and Hans von Storch. "The Dynamics of Tides and Climate." In Computer Modelling in Atmospheric and Oceanic Sciences, 69–89. Berlin, Heidelberg: Springer Berlin Heidelberg, 2004. http://dx.doi.org/10.1007/978-3-662-06381-1_4.

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4

England, S. L. "A Review of the Effects of Non-migrating Atmospheric Tides on the Earth’s Low-Latitude Ionosphere." In Dynamic Coupling Between Earth’s Atmospheric and Plasma Environments, 211–36. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-5677-3_6.

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Pancheva, Dora, and Plamen Mukhtarov. "Global Response of the Ionosphere to Atmospheric Tides Forced from Below: Recent Progress Based on Satellite Measurements." In Dynamic Coupling Between Earth’s Atmospheric and Plasma Environments, 175–209. New York, NY: Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4614-5677-3_5.

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6

Pancheva, Dora, and Plamen Mukhtarov. "Atmospheric Tides and Planetary Waves: Recent Progress Based on SABER/TIMED Temperature Measurements (2002–2007)." In Aeronomy of the Earth's Atmosphere and Ionosphere, 19–56. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0326-1_2.

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7

Kil, Hyosub, and Larry J. Paxton. "Causal Link of Longitudinal Plasma Density Structure to Vertical Plasma Drift and Atmospheric Tides – A Review." In Aeronomy of the Earth's Atmosphere and Ionosphere, 349–61. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-94-007-0326-1_26.

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8

Robertson, Robin, Laurie Padman, and Gary D. Egbert. "Tides in the Weddell Sea." In Ocean, Ice, and Atmosphere: Interactions at the Antarctic Continental Margin, 341–69. Washington, D. C.: American Geophysical Union, 2013. http://dx.doi.org/10.1029/ar075p0341.

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Rauh, Andreas, and Agnes Pfrang. "Learning Atmospheres in Pandemic Times. Different Realities." In Phänomenologische Erziehungswissenschaft, 265–81. Wiesbaden: Springer Fachmedien Wiesbaden, 2025. https://doi.org/10.1007/978-3-658-47518-5_14.

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Bush, Andrew B. G. "Glaciation During Times of Enhanced/Reduced Atmospheric Carbon Dioxide." In Encyclopedia of Earth Sciences Series, 366–72. Dordrecht: Springer Netherlands, 2011. http://dx.doi.org/10.1007/978-90-481-2642-2_188.

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Atti di convegni sul tema "Atmospheric tides"

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Burda, Paul A. "Atmospheric Corrosion of Aluminum Ingots." In CORROSION 1987, 1–14. NACE International, 1987. https://doi.org/10.5006/c1987-87419.

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Abstract The atmospheric corrosion was evaluated on aluminum ingots and sheets from 99.6% Al after 60 month of exposure in clean atmosphere (with high condensation) and in an unheated concrete warehouse at the same location. The ingots were stored in the rectangular storage stacks on top of each other. A chemical method of corrosion products removal was developed, using phosphoric acid and chromium oxide at 100°C (212°F) and allowing the corrosion loss determination without initial weight data. The laboratory apparatus was built for this purpose. The composition of the products was calculated from aluminum content, determined in known volume of corrosion products applying chemical stoichiometry. "Degree of Hydration (°H)" was derived to express the nature of corrosion products. There was found no difference between composition of corrosion products in free atmosphere and in unheated warehouse. The corrosion products were formed by hydrated aluminum hydroxide Al(°H)3. 3H2O. The atmospheric corrosion rate was dependent on the mass and the method of ingots exposure. The larger mass of aluminum exhibited higher corrosion rates (eight times higher in the storage and four times higher in the open atmosphere). The corrosion rate of ingots was ten to twenty-four times higher in the open atmosphere than in the unheated storage area. It was also demonstrated in parallel laboratory studies that the simultaneous interactions between the moisture and temperature of air and metal surface, including the metal mass and its heat capacity, are important factors of the atmospheric corrosion kinetics.

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Bierwirth, M., J. Goellner, and A. Heyn. "Passivation of Stainless Steels Measured with Electrochemical Noise." In CORROSION 2006, 1–8. NACE International, 2006. https://doi.org/10.5006/c2006-06428.

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Abstract Stainless steels are widely used as construction materials due to their corrosion resistance obtained by stable passive layers. The formation of those passive layers under atmospheric conditions depends not only on the surface treatment. It depends also on the exposure time in a certain atmosphere after the surface treatment until a stable passive state is reached. This paper shows the ability to measure the formation process of the passive layer with electrochemical noise and to determine necessary exposure times to avoid pitting of freshly treated surfaces. Specimens of SS316 were exposed to two different atmospheric conditions after mechanically grinding. Measurements were performed with a set-up measuring cell and a 1M NaCl solution at pH3. Potential and potential noise data were taken for different exposure times at different locations on the surface of the same specimen. The potential data show clearly the active or passive state of the specimen, while the noise data give further information about the activity of several metastable pits on the surface at the passive state. A decrease of surface activity at increasing exposure times indicating a further improvement of the passive layer can be shown.

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Schütze, M., and M. Nöth. "Protective Coatings for High Temperatures and High Sulfur - Low Oxygen Environments." In CORROSION 1998, 1–14. NACE International, 1998. https://doi.org/10.5006/c1998-98188.

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Abstract Different coatings based on MoSi2, TiAl or FeSi were applied by air plasma spraying (APS) to low alloy steel and tested at 700°C in an atmosphere of pS2 = 10-6 bar and pO2 = 4.2 x 10-27 bar which is representative for atmospheres in certain industrial gasification processes. Tests were run isothermally and with thermal cycling for times up to 1000 hrs. In particular coatings based on TiAl provide a significant improvement of sulfidation resistance.

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Cooper, K. R., R. G. Kelly, and E. L. Colvin. "The Correlation between Crack Chemistry and Crack Growth Behavior of 7xxx Series Aluminum Alloys: A Comparison of Field and Laboratory Tests." In CORROSION 1999, 1–18. NACE International, 1999. https://doi.org/10.5006/c1999-99153.

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Abstract The crack growth kinetics and solution chemistry developed within environment-assisted cracks (EAC) grown in laboratory tests and long-term field exposures of high-strength Al-Zn-Mg-Cu alloys were assessed. For both test programs, peak-aged (T651) material exhibited crack growth kinetics 103 to 104 times that of overaged (T7X51). Laboratory crack growth studies in aqueous CrO42-/Cl- environments demonstrated the characteristic enhanced resistance of overaged Al-Zn-Mg-Cu alloys to intergranular EAC crack propagation relative to peak-aged tempers. The laboratory environment is suitable for alloy development and mechanistic studies of environment-assisted cracking in these alloys. Cracks within fracture specimens exposed to an industrial atmosphere contained predominately chloride and sulfate with minor amounts of nitrate, nitrite and organic acids. The dominant cations found were aluminum, zinc and magnesium dissolved from the alloy in addition to sodium and potassium from the external atmosphere. Environment-assisted crack growth behavior during atmospheric exposure was not correlated to the crack chemistry. The crack solution of field-exposed specimens was similar for peak-aged and overaged material, attaining a pH of 3 to 3.8. The crack solution of these specimens was probably dominated by crevice corrosion. In contrast to the atmospheric tests, the low corrosiveness of the laboratory environment facilitated differentiation of peak-aged and overaged crack chemistry. Whereas peak-aged material developed an acidic, concentrated Al-salt solution at the crack tip, overaged material showed little alteration of the crack environment from that of the external solution.

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Valujeva, Kristine, Jovita Pilecka-Ulcugaceva, Kristaps Siltumens, Olga Skiste, and Inga Grinfelde. "EFFECTS OF TILLAGE SYSTEMS ON METHANE ASSIMILATION IN CAMBIC CALCISOL AND IMPLICATIONS FOR CLIMATE CHANGE MITIGATION." In 24th SGEM International Multidisciplinary Scientific GeoConference 2024, 193–200. STEF92 Technology, 2024. https://doi.org/10.5593/sgem2024v/4.2/s18.27.

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Well-aerated soils are essential for methane (CH4) uptake from the atmosphere, acting as significant sinks for this greenhouse gas, which has a global warming potential 25 times greater than that of carbon dioxide (CO2). These soils contain methanotrophic bacteria, which oxidize CH4 and thereby reduce atmospheric methane concentrations. The potential of soils to assimilate CH4 depends on factors such as soil type and moisture regime. This study investigates the ability of clay soil Cambic Calcisol to assimilate CH4. Measurements were conducted at an experimental site with two tillage systems and two crop rotations from 2018 to 2023, with observations taken every two weeks from April to October. Experimental plots under conventional tillage demonstrated a higher rate of CH4 assimilation compared to reduced tillage plots (-4.1 g CH4 ha-1 day-1 and -3.5 g CH4 ha-1 day-1, respectively). CH4 uptake by soils plays a vital role in regulating methane emissions, making soil management practices a key factor in climate change mitigation efforts. Understanding the variables influencing CH4 assimilation is crucial for optimizing land-use strategies to enhance greenhouse gas mitigation.

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Zeszut, Ronald, David Rubino, and Douglas C. Hansen. "Comparison of Atmospheric Corrosion of Silver across Multiple Locations." In CONFERENCE 2022, 1–13. AMPP, 2022. https://doi.org/10.5006/c2022-17621.

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Abstract Atmospheric corrosion of silver from multiple beachfront sites in Florida was examined by coulometric reduction. Exposure was performed at the US Naval Research Laboratory in Key West, Kennedy Space Center, and Daytona Beach. Coupons were exposed for 3-18 months. Silver chloride and sulfide were identified and quantified by a galvanic reduction technique, which separately characterized the corrosion products on the front and back of each coupon. Differences were observed between sites for both chloride and sulfide growth rate. Silver chloride grew fastest at Daytona Beach, but no silver sulfide was observed on any samples at this site. Additionally, corrosion was observed to occur differently on the front and back of the samples. Increasing exposure times showed increasing corrosion film thickness, and exposure at different sites showed different corrosion film thicknesses and compositions. Additionally, the coulometric reduction technique has been examined in-depth to identify and mitigate possible difficulties in results interpretation which arise from thick and/or multi-component films.

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Savichev, Vladimir, Takil Tarkan, Yong Wang, Jorge J. Rocca, and Vladimir Chvykov. "Free Beam Propagation Multipass Cells for Post-Compression of High-Energy Laser Pulses." In CLEO: Science and Innovations, STh4I.2. Washington, D.C.: Optica Publishing Group, 2024. http://dx.doi.org/10.1364/cleo_si.2024.sth4i.2.

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Post-compression of high energy laser pulses by folded free propagation MPC in atmospheric air is presented. Proof-of-principle experiments demonstrate the ability of this scheme to compress the 0.1J-level energy pulses up to 10 times scalable.

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Townsend, H. E., and A. R. Borzillo. "Twenty-Year Atmospheric Corrosion Tests of Hot-Dip Coated Sheet Steel." In CORROSION 1987, 1–9. NACE International, 1987. https://doi.org/10.5006/c1987-87421.

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Abstract Steel sheets coated with hot-dip aluminum, zinc, and a series of binary aluminum-zinc alloys have been tested for corrosion resistance in marine, industrial, and rural environments for twenty years. The results of these tests show that, compared to zinc coatings, a 55% Al-Zn alloy coating is several times more durable. Compared to aluminum coatings, the 55% Al-Zn coating provides superior galvanic protection in industrial and rural environments, and has much better resistance to crevice corrosion in marine environments. These tests demonstrate conclusively that, among alloy coatings within the Al-Zn binary system, the 55% Al-Zn alloy coating provides the best combination of durability and galvanic characteristics for long-term corrosion protection of sheet steel. 55% Al-Zn alloy coatings produced on a large-scale commercial coating line exhibited greater durability than those produced earlier on a pilot laboratory facility. This difference is attributed to decreased corrosivity of the test environments and to improvements in the coating process. These improvements include faster cooling of the coating during solidification and application of chromate passivation.

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Macha, Erica, Alexander Lilly, James Dante, Rachel Black, Travis Eliason, and Victor Rodrigez-Santiago. "Development and Demonstration of RH-Controlled Accelerated Atmospheric Corrosion Test Environments." In CORROSION 2021, 1–9. AMPP, 2021. https://doi.org/10.5006/c2021-16819.

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Abstract In this work, we discuss the development of accelerated atmospheric corrosion test cycles designed to produce similar types of corrosion damage observed during field exposures while also highly accelerating the formation of that damage. These four cycles vary the times spent in three different ranges of RH (high, intermediate, and low) while maintaining a constant temperature. The ratios of testing time spent in each of these three RH ranges were inspired by the RH profiles obtained during field exposures in a variety of locations throughout the continental U.S. To ensure similar performance between the two testing labs involved in performing testing, extensive qualification of the test environment was performed prior to and during testing, including analysis of the salt depositions as well as examination of the RH profile of the test chamber. After the test chambers were found to be performing similarly, lapped 7075 aluminum coupons with galvanic recessed fasteners were coated with a variety of military-grade coating systems, and subjected to 500 or 1000 hours in the test environment. Analysis of the resulting corrosion is presented and compared between the different cycles.

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Dean, Sheldon W., and David B. Reiser. "Comparison of the Atmospheric Corrosion Rates of Wires and Flat Panels." In CORROSION 2000, 1–23. NACE International, 2000. https://doi.org/10.5006/c2000-00455.

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Abstract A series of regression analyses were made on the one-year corrosion measurements of flat panel and wire helix specimens. There was a very strong relationship between the wire and panel results with the wire specimens yielding higher rates than the panels, but approaching the panel rates at the highest rates for all four metals. A second series of regression analyses between the residuals from the panel-helix regression was run against environmental variables. The residuals showed a significant positive relationship with sulfur dioxide for zinc, chloride for copper, and both chloride and sulfur dioxide for aluminum. This indicates that increases in the environmental variable increased the corrosion rate of the wires more than flat panels. An estimate of the gas phase convective mass transfer rate of sulfur dioxide to wires as compared to flat surfaces showed that sulfur dioxide would diffuse to wire surfaces about three times the rate to a flat panel. The collection efficiency of chlorides to wire surfaces would likewise be greater than flat surfaces, but the actual rates would depend on the particle size and wind velocity. These results show that wire helix specimens are not equivalent to flat panels in estimating atmospheric corrosivity.

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Rapporti di organizzazioni sul tema "Atmospheric tides"

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O'Neill, Clare, Andy Saulter, Christopher Stokes, and Breogán Gómez. Application of bias correction to the Met Office operational storm surge forecast. Met Office, January 2025. https://doi.org/10.62998/tymo5223.

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The Met Office runs an operational storm surge forecast system for the UK based on a 7 km configuration of NEMO forced by wind and air pressure from Met Office global atmosphere forecasts. The water level forecast comprises the surge residual from the model added to the harmonic tide prediction derived from observations. A new automated bias correction has been added to the system to improve forecast performance. The correction has 3 components: a mean sea level correction to account for different mean sea levels in the forced and unforced model runs, a monthly correction to account for the atmospheric component included in harmonic tide predictions, and an empirical constant correction to account for sea level rise and other effects not currently included in the surge model. The correction scheme is shown to significantly improve the overall forecast skill compared to the original uncorrected forecast. The number of forecasts that fall outside the target 20 cm accuracy is reduced from an average of 17% (whole tide cycle) and 22% (high waters only) to less than 6% (in both cases). The average RMS error is reduced from 14 cm (whole tide cycle) and 15 cm (high waters) to 9 cm (in both cases) and the average bias is reduced from 11 cm to 1cm (all tide cycle) and 13 cm to 3 cm (high waters). The correction was added to the operational system in August 2024.

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Posey, Pamela G., Ruth H. Preller, Gretchen M. Dawson, and Suzanne N. Carroll. Software Test Description (STD) for the Globally Relocatable Navy Tide/Atmospheric Modeling System (PCTides). Fort Belvoir, VA: Defense Technical Information Center, May 2002. http://dx.doi.org/10.21236/ada402376.

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Gasim, Anwar, Lester Hunt, and Jeyhun Mikayilov. Methane Emissions Baseline Forecasts for Saudi Arabia Using the Structural Time Series Model and Autometrics. King Abdullah Petroleum Studies and Research Center, May 2023. http://dx.doi.org/10.30573/ks--2023-dp08.

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Reducing methane (CH4) emissions is key to near-term efforts to limit global warming. CH4 is the second most abundant anthropogenic greenhouse gas (GHG) in the atmosphere after carbon dioxide (CO2). The production, transport, and consumption of fossil fuels, in addition to waste and agriculture, account for most anthropogenic CH4 emissions globally (IPCC 2018). Although CH4has only a 12-year lifetime in the atmosphere, it is 84 times more potent per ton than CO2 in a 20-year period and 28 times more potent in a 100-year period (IPCC 2018). The drastically stronger short-term potency of CH4 explains why its short-term impact on global warming is considerably greater than that of CO2. Therefore, meeting the goals of the Paris Agreement necessitates not only decarbonization but also significant CH4 emissions reductions, especially in the near term.

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Preller, Ruth H., Pamela G. Posey, Graeme D. Hubbert, and Suzanne N. Carroll. User's Manual for the Globally Relocatable Navy Tide/Atmosphere Modeling System (PCTides). Fort Belvoir, VA: Defense Technical Information Center, October 2001. http://dx.doi.org/10.21236/ada390560.

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Preller, Ruth H., Pamela G. Posey, Suzanne N. Carroll, and Laine B. Orsi. Software Requirements Specification for the Globally Relocatable Navy Tide/Atmosphere Modeling System (PCTides). Fort Belvoir, VA: Defense Technical Information Center, April 2001. http://dx.doi.org/10.21236/ada389765.

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Preller, Ruth H., Pamela G. Posey, Suzanne N. Carroll, and Graeme D. Hubbert. Software Design Description for the Globally Relocatable Navy Tide/Atmosphere Modeling System (PCTides). Fort Belvoir, VA: Defense Technical Information Center, April 2001. http://dx.doi.org/10.21236/ada389770.

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ESA, ESA EOP-SM, and NASA SMD NASA. Exploring Earth’s Interface with Space – The Scientific Case for a Satellite Mission to the Lower Thermosphere-Ionosphere Transition Region. ESA, July 2024. http://dx.doi.org/10.5270/esa-nasa.lti-sc.2024-07-v1.0.

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Exploring Earth’s Interface with Space – The Scientific Case for a Satellite Mission to the Lower Thermosphere-Ionosphere Transition Region SUMMARY This report describes the scientific case for a mission concept to study the Earth’s Lower Thermosphere-Ionosphere – the LTI – which is the interface region between our atmosphere and space. The LTI is situated at altitudes between 100-200 km and is uniquely characterized by complex interactions between the co-existing neutral and ionized gases. The LTI receives and dissipates hundreds of gigajoules of energy every second from above due to solar wind interactions with our planet’s magnetosphere. Simultaneously, this region continuously receives energy and momentum input from below in the form of tides and gravity waves originating in the lower and middle atmosphere as well as impulsive input from thunderstorms, volcanoes, and earthquakes, whose energy content rivals that provided by the magnetosphere. The LTI responds dramatically to all of these driving forces producing large variations in many key properties, such as neutral and plasma number densities, motions, temperatures, and composition, as well as electric fields, conductivity, and currents. Importantly, the LTI also acts as a critical interface that subsequently regulates this energy transfer from the magnetosphere above and from the neutral atmosphere below.

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Brewer, K. D. Water level data from the Bells Corners Borehole Calibration Facility (2019-2021), Ottawa, Ontario. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/330087.

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The Geological Survey of Canada's deep borehole test site at the Bells Corners Borehole Calibration Facility in Ottawa, Ontario, has been in use since the 1980's for the development and calibration of geophysical logging instrumentation. In more recent times, the need for monitored deep borehole sites in Canada is increasingly important for long-term research into groundwater flow through fractured bedrock, and surface to groundwater interaction. In 2019, the facility underwent repairs to reopen deep boreholes, replace surface casings, and install atmospheric monitoring equipment. This report documents new groundwater level datasets in three of the six boreholes in the well cluster from March 2019 to October 2021. The compilation also integrates rainfall and air temperature data from a rain gauge installed on the site which provides insight into the rapid response times of this fractured bedrock system. This new water level information augments the growing number of datasets supporting the ongoing study of hydrogeological conditions at the calibration facility.

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Alter, Ross, Michelle Swearingen, and Mihan McKenna. The influence of mesoscale atmospheric convection on local infrasound propagation. Engineer Research and Development Center (U.S.), February 2024. http://dx.doi.org/10.21079/11681/48157.

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Infrasound—that is, acoustic waves with frequencies below the threshold of human hearing—has historically been used to detect and locate distant explosive events over global ranges (≥1,000 km). Simulations over these ranges have traditionally relied on large-scale, synoptic meteorological information. However, infrasound propagation over shorter, local ranges (0–100 km) may be affected by smaller, mesoscale meteorological features. To identify the effects of these mesoscale meteorological features on local infrasound propagation, simulations were conducted using the Weather Research and Forecasting (WRF) meteorological model to approximate the meteorological conditions associated with a series of historical, small-scale explosive test events that occurred at the Big Black Test Site in Bovina, Mississippi. These meteorological conditions were then incorporated into a full-wave acoustic model to generate meteorology-informed predictions of infrasound propagation. A series of WRF simulations was conducted with varying degrees of horizontal resolution—1, 3, and 15 km—to investigate the spatial sensitivity of these infrasound predictions. The results illustrate that convective precipitation events demonstrate potentially observable effects on local infrasound propagation due to strong, heterogeneous gradients in temperature and wind associated with the convective events themselves. Therefore, to accurately predict infrasound propagation on local scales, it may be necessary to use convection-permitting meteorological models with a horizontal resolution ≤4 km at locations and times that support mesoscale convective activity.

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Chaiyapuck, Piyaporn, Supatra Jinawath, and Wada, Shigetaka. Sintering of Si[subscript 3]N[subscript 4] ceramics in an air atmosphere furnace. Chulalongkorn University, 2003. https://doi.org/10.58837/chula.res.2003.36.

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Pressed specimens of α-Si3N4 (SN-E10) powder with Y2O3 and Al2O3 additives were successfully sintered without a serious mass loss at a temperature range of 1550-1700°C in an air atmosphere furnace using a set of specially designed, high purity A12O3 crucibles, Si3N4 packing powder and A12O3 filler. The agglomeration on sintering of both the packing powder and Al2O3 filler was encountered, but it could be optimized by using coarse size materials. Additionally, the deterioration of Al2O3 crucibles leading to cracking after several times of usage is still to be improved. On the contrary, Si3N4 ceramics could be sintered to full density (98%) reproducibly at 1700°C for 2 hours with an average biaxial bending strength of 420 MPa, Vickers hardness of 16 GPa and fracture toughness, K1C, of 5 MPam ½.

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