Performance des lieux d'enfouissement sanitaire de Laterrière et de Ste-Sophie, Québec, Canada

Ce travail décrit les caractéristiques hydrogéologiques et chimiques de deux lieux d'enfouissement de déchets municipaux localisés au Québec. Le site de Laterrière est en opération depuis 1971 dans une ancienne sablière. Sous les dépôts meubles, la topographie du sotte rocheux est marquée par une vallée qui forme une limite imperméable à l'aquifère de sable et impose un écoulement convergent de l'eau souterraine vers la rivière Chicoutimi. Le site de Ste-Sophie, en opération depuis 1976, repose sur une couche de 3,5 mètres de sables fins saturés recouvrant un lit d'argile marine. La surélévation de la nappe dans les déchets favorise un écoulement divergent vers le périmètre de la zone d'enfouissement.Un réseau de piézomètres installé en bordure des deux sites a permis pendant trente mois de prélever des échantillons d'eau et de les analyser. Dans chaque panache de contamination, l'alcalinité, les ions majeurs Na+, K+, Ca2+, Mg2+, Cl¯, le fer, le manganèse, l'azote total et ammoniacal, les DCO et DBO5 montrent des concentrations généralement supérieures à celles de L'eau naturelle ambiante. A proximité des deux Lieux d'enfouissement, les teneurs en cadmium, chrome, nickel et plomb excèdent les normes québécoises de potabiLité de l'eau. Dans chaque cas, ta distribution des contaminants est surtout régie par le réseau d'écoulement. La dispersion hydrodynamique et les réactions géochimiques dans le sous-sol sont des processus importants d'atténuation des contaminants.This paper describes the hydrogeological and geochemical features of two sanitary landfill sites located in the Province of Quebec : Laterriere and Ste-Sophie. The main objective is to evaluate the leachate attenuation performance of each site. For this project, the Quebec Ministry of the Environment chose two sites with contrasting hydrogeological settings.The Laterriere landfill, in operation since 1971, covers an area of about 32 ha. The refuse is deposited in an old sandpit and the landfill boundary is located 400 meters away from the Chicoutimi River, 25 meters above the stream water level. The bedrock topography shows a valley under the landfill which acts an an impervious base for the sand aquifer and induces a convergent groundwater flow towards the river.The Ste-Sophie landfill covers an area of 48 ha and began operating in 1976. The refuse zone is located on flat ground 350 meters away from the Ruisseau-aux-Castors. The refuse is deposited on a 3.5 meter layer of fine sands nearly saturated overlying a marine clay bed. A water table mound is observed beneath the landfill, resulting in diverging low lines outward from the center of the Landfill.For each site, the occurence and migration of contaminants was investigated using networks of piezometers. Sampling was performed monthly over a period of thirty months and thirty parameters were analyzed on each sample. The analytical results were entered in a database and treated by statistical methods.The shape of each contamination plume is controlled mainly by the groundwater flow system. At Laterriere, the plume is restricted to a narrow path between the landfill and the river and inside a bedrock valley. This flow net has been simulated by a two-dimensional finite elements model. At Ste-Sophie, the divergence of flow lines due to groundwater mounding beneath the site causes dispersion of contaminants around the landfill. The use of an analytical solution shows that longitudinal dispersivity is a major process of contaminant migration.For the two landfills, the highest concentrations of contaminants occur directly beneath or close to the boundaries of the landfills. Total alkalinity, Na+, K+, Ca2+, Mg2+, Cl¯, iron, manganèse, total and ammoniacal nitrogen, chemical and biological oxygen demand (COD and BOD) are much above background levels throughout the plume. Sulfate is also a major contaminant at Ste-Sophie with concentration of 1100/mg/l. The concentrations of cadmium, chrome, nickel and lead exceed the drinking water standards near the two landfill sites but they decline rapidly in the direction of flow. At Laterriere, the decline in chloride concentration measured at the discharge point S-23 is about 85 % while the decline of reactive contaminants, such as iron and COD, is respectively 98 and 99.7 %.Finally, we discuss hydrogeological criteria for landfill site selection in Quebec

Kinetic Theory for the Interpretation of Measurements on Fluctuations in Radiation Distributions in Finite, Inhomogeneous Systems

A kinetic (transport) theory is presented for the first- and second-order (and, if necessary, higher) statistical moments of the number densities of the various particles and/or photons that describe the observable fluctuations in the radiation distribution from an emitting system. This treatment is particularly suitable for the analysis of finite, inhomogeneous systems that may be composed of detectors located outside of a radiating source. Because we are largely concerned with the utility of kinetic theory as a physical theory, considerable emphasis is placed upon an appropriate theoretical description of the actual observables of given experimental situations. The quantum Liouville equation is used to generate the coupled set of transport equations, and basic criteria for the applicability of transport and wave theories are discussed. Quantum-statistical effects are also quite naturally accounted for in cases where they are relevant. It is seen that fluctuation measurements are useful for inferring information relevant to the dynamic interactions within a given system. Such measurements often enjoy the feature of being passive with respect to the interacting system of interest. To illustrate the use of this spatially dependent form of kinetic theory on a system emitting optical radiation, we consider an example that interprets a fluctuation measurement on the radiation emergent from a finite nondispersive blackbody. We conclude by discussing the problems of statistical coupling between the radiation field and detector atom distributionsPeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/86139/1/PhysRev.163.162-RKO.pd

A Boreing Night of Observations of the Upper Mesosphere and Lower Thermosphere Over the Andes Lidar Observatory

A very high-spatial resolution (∼21-23 m pixel at 85 km altitude) OH airglow imager at the Andes Lidar Observatory at Cerro Pach´on, Chile observed considerable ducted wave activity on the night of October 29-30, 2016. This instrument was collocated with a Na wind-temperature lidar that provided data revealing the occurrence of strong ducts. A large field of view OH and greenline airglow imager showed waves present over a vertical extent consistent with the altitudes of the ducting features identified in the lidar profiles. While waves that appeared to be ducted were seen in all imagers throughout the observation interval, the wave train seen in the OH images at earlier times had a distinct leading non-sinusoidal phase followed by several, lower-amplitude, more sinusoidal phases, suggesting a likely bore. The leading phase exhibited significant dissipation via small-scale secondary instabilities suggesting vortex rings that progressed rapidly to smaller scales and turbulence (the latter not fully resolved) thereafter. The motions of these small-scale features were consistent with their location in the duct at or below ∼83-84 km. Bore dissipation caused a momentum flux divergence and a local acceleration of the mean flow within the duct along the direction of the initial bore propagation. A number of these features are consistent with mesospheric bores observed or modeled in previous studies

Reactor Noise Analysis from Observations of the High Energy Radiation from the Reactor Core

US AEChttp://deepblue.lib.umich.edu/bitstream/2027.42/85749/1/UCRL-14719-T Gelinas+Osborn.PDF2

Kelvin-Helmholtz Billow Interactions and Instabilities In The Mesosphere Over the Andes Lidar Observatory: 1. Observations

A very high spatial resolution (∼25 m pixel at 90 km altitude) OH airglow imager was installed at the Andes Lidar Observatory on Cerro Pachón, Chile, in February 2016. This instrument was collocated with a Na wind-temperature lidar. On 1 March 2016, the lidar data showed that the atmosphere was dynamically unstable before 0100 UT and thus conducive to the formation of Kelvin-Helmholtz instabilities (KHIs). The imager revealed the presence of a KHI and an apparent atmospheric gravity wave (AGW) propagating approximately perpendicular to the plane of primary KHI motions. The AGW appears to have induced modulations of the shear layer leading to misalignments of the emerging KHI billows. These enabled strong KHI billow interactions, as they achieved large amplitudes and a rapid transition to turbulence thereafter. The interactions manifested themselves as vortex tube and knot features that were earlier identified in laboratory studies, as discussed in Thorpe (1987, https://doi.org/10.1029/ JC092iC05p05231; 2002, https://doi.org/10.1002/qj.200212858307) and inferred to be widespread in the atmosphere based on features seen in tropospheric clouds but which have never been identified in previous upper atmospheric observations. This study presents the first high-resolution airglow imaging observation of these KHI interaction dynamics that drive rapid transitions to turbulence and suggest the potential importance of these dynamics in the mesosphere and at other altitudes. A companion paper (Fritts et al., 2020, https://doi.org/10.1029/2020JD033412) modeling these dynamics confirms that the vortex tubes and knots yield more rapid and significantly enhanced turbulence relative to the internal instabilities of individual KHI billows

A Measurement of Stimulated Emission From 83m-Kr(m)

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Simultaneous observations of the phase-locked 2 day wave at Adelaide, Cerro Pachon, and Darwin

The Southern Hemisphere summer 2 day wave (TDW) is the most dramatic large-scale event of the upper mesosphere. The winds accelerate over _1 week, may attain \u3e 70 m/s, and are often accompanied by a near disappearance of the diurnal tide and stabilization of the period close to 48 h. We denote this as the phase-locked 2 day wave (PL/TDW). We have examined airglow and meteor radar (MR) wind data from the Andes Lidar Observatory (Cerro Pachon, Chile:30¡S, 289.3¡E), MR data from Darwin (12.5¡S, 131¡E) and airglow and medium frequency radar data from the University of Adelaide (34.7¡S, 138.6¡E) for the behavior of the TDW during the austral summers of 2010, 2012, and 2013. The Cerro Pachon and Adelaide sites are located at similar latitudes separated in longitude by about 120¡. We find a remarkable coincidence between the TDW oscillations at Chile and Adelaide for the period January-February 2010. The oscillations are nearly in phase in terms of local time and the minima and maxima repeat at nearly the same local time from cycle to cycle consistent with a phase-locked wave number 3 TDW. Data for this and other years (including Darwin) show that the amplitude of the diurnal tide decreases when the TDW is largest and that this occurs when the period is close to 48 h. These observations support the proposal that the PL/TDW is a subharmonic parametric instability wherein the diurnal tide transfers energy to a TDW that is resonant at nearly 48 h. ©2015. American Geophysical Union. All Rights Reserved

The Life Cycle of Instability Features Measured from the Andes Lidar Observatory Over Cerro Pachon on 24 March 2012

The Aerospace Corporation\u27s Nightglow Imager (ANI) observes nighttime OH emission (near 1.6 µm) every 2 s over an approximate 73¬∞ field of view. ANI had previously been used to study instability features seen over Maui. Here we describe observations of instabilities seen from 5 to 8 UT on 24 March 2012 over Cerro Pachon, Chile, and compare them with previous results from Maui, with theory, and with Direct Numerical Simulations (DNS). The atmosphere had reduced stability because of the large negative temperature gradients measured by a Na lidar. Thus, regions of dynamical and convective instabilities are expected to form, depending on the value of the Richardson number. Bright primary instabilities are formed with a horizontal wavelength near 9 km and showed the subsequent formation of secondary instabilities, rarely seen over Maui, consistent with the primaries being dynamical instabilities. The ratio of the primary to secondary horizontal wavelength was greater over Chile than over Maui. After dissipation of the instabilities, smaller-scale features appeared with sizes in the buoyancy subrange between 1.5 and 6 km. Their size spectra were consistent with the model of Weinstock (1978) if the turbulence is considered to be increasing. The DNS results produce secondary instabilities with sizes comparable to what is seen in the images although their spectra are somewhat steeper than is observed. However, the DNS results also show that after the complete decay of the primary features, scale sizes considerably smaller than 1 km are produced and these cannot be seen by the ANI instrument