Airborne radar and in-situ observations of a shallow stratus with drizzle

Observations were made of a shallow stratus of upslope origin using an aircraft equipped with insitu probes and with a vertically-pointing radar of 3-mm wavelength. A cloud layer of 300 m thickness was found below the inversion; an additional layer of 100 m thickness was located within the inversion. The coldest temperature within the cloud was -2°C and the cloud contained no ice particles. Drizzle drops up to 180 Am were present in both cloud layers.The observations reveal precipitation and air motion structures of approximately 1 km horizontal dimensions. The origin of this organization appears to be weak convection. In addition, mixing played an important role in forming the cloud droplet and drizzle drop size distributions.     

Life cycle assessment of pyrolysis–gasification as an emerging municipal solid waste treatment technology

Waste-to-energy technologies are considered as one of the key waste treatment technologies due to their energy and heat recovery efficiencies from the waste. A number of research studies were accomplished to understand the potential environmental burdens from emerging waste treatment technologies such as pyrolysis–gasification (PG). The aim of this study was to examine the PG of municipal solid waste (MSW) treatment process through a life cycle assessment (LCA) method. The study also includes a comparative LCA model of PG and incineration to identify the potential environmental burdens from the existing (incineration) and emerging (PG) waste treatment technologies. This study focused on ten environmental impact categories under two different scenarios, namely: (a) LCA model of PG and (b) comparative LCA model of PG and incineration. The scenario (a) showed that PG had significant environmental burdens in the aquatic eco-toxicity and the global warming potential impact categories. The comparative scenario (b) of PG and incineration of MSW showed that PG had comparatively lower potential environmental burdens in acidification, eutrophication, and aquatic eco-toxicity. Both LCA models showed that the environmental burdens were mainly caused by the volume of the thermal gas (emissions) produced from these two technologies and the final residue to disposal. Therefore, the results indicate that the efficiency and environmental burdens of the emerging technologies are dependent on the emissions and the production of final residue to the landfill.     

Exploring the diverse potentials of <Emphasis Type="Italic">Planococcus</Emphasis> sp. TRC1 for the deconstruction of recalcitrant kraft lignin

Kraft lignin (KL) is the chief contaminant which is responsible for dark coloration, toxicity and high chemical oxygen demand (COD) of paper pulp mill effluent. The present study investigated the diverse potentials of Planococcus sp. TRC1 in the biodegradation of KL. Preliminary evaluation indicated that the strain was able to grow on broad spectrum of lignin-derived compounds, decolorize lignin-mimicking dyes and catabolize substrates of ligninolytic enzymes. Response surface methodology (RSM) was executed to perform the optimization of different process parameters. The results displayed that Planococcus sp. TRC1 could completely utilize 100 mg L^?1 of KL and 78% of 200 mg L^?1 of KL as sole source of carbon with concurrent reduction in COD and color. The biokinetic details of KL biodegradation showed that the values of \(\mu^{*}\), µ _max, \(q^{*}\) and q _max were 0.018 h^?1, 0.01 h^?1, 0.023 g g^?1 h^?1 and 0.05 g g^?1 h^?1, respectively. UV–visible spectrophotometry, SEM and FTIR indicated the significant alterations in the surface morphology, functional groups and chromophores during the course of biodegradation. XRD revealed the emergence of peak signifying the formation of low molecular weight intermediates after bacterial treatment. Considering the environmental impact, bacterial-treated KL illustrated less phytotoxicity using Vigna radiata seed bioassay. These results suggested that Planococcus sp. TRC1 could be a promising strain for the degradation of KL in an ecofriendly way.     

Towards medium-term (order of months) morphodynamic modelling of the Teign estuary, UK

The main objective of this paper is to address the principal mechanisms involved in the medium-term (order of months to years) morphodynamic evolution of estuaries through the application of a process-based numerical modelling. The Teign estuary (Teignmouth, UK) is the selected site. The system is forced by the macrotidal semi-diurnal tide in the English Channel and is perturbed to a minor extent by high river discharge events (freshets). Although waves have a definite influence on the adjacent coastal area, Wells (Teignmouth Quay Development Environmental Statement: Changes to Physical Processes. Report R.984c:140. ABP Marine Environmental Research Ltd., Southampton, 2002b) suggested that swell waves do not enter the estuary. Hence, wave effects are neglected in this study, as only tides and the river discharge are taken into account. The sediment grain size is highly variable, but mainly sandy. Within the frame of the COAST3D project (), four bathymetric surveys of the adjacent coastal area were carried out at a nearly weekly intervals. The outer estuary and the adjacent coastal area were also surveyed every 6 months as part of the COASTVIEW project (). Based on these data and on continuously measured parameters, such as water level, waves, wind and river discharge, numerical modelling of the morphodynamic processes can be tested. To replicate the morphological changes in the medium-term within a feasible simulation time, forcing conditions are reduced through the use of an input reduction method (called ensemble technique). In this study, simulations are based on the coupling between Telemac-2D and its non-cohesive sediment transport module, Sisyphe (version 5.3 for both modules). Three different sediment transport formulae were tested: (1) Engelund and Hansen (A monograph on sediment transport in alluvial streams, 3rd edn. Technological University of Denmark, Copenhagen, 1967) including the modifications proposed by Chollet and Cunge (J Hydraul Eng 17(1):1–13, 1979); (2) Bijker (Mechanics of sediment transport by the combination of waves and current. In: Design and reliability of coastal structures. 23rd international conference on Coastal Engineering, pp 147–173, 1968) and (3) Soulsby (Dynamics of Marine Sands. A manual for practical applications. HR Wallingford, Wallingford, p 142, 1997) modified version of van Rijn [J Hydraul Eng 110(10):1431–1456, 1984a, J Hydraul Eng 110(11):1613–1641, 1984b] formulation. Both a qualitative (i.e. visual comparison) and a quantitative tool [Brier Skill Score (BSS); described in Sutherland et al. in Coast Eng 51:917–939, 2004b] are applied to assess the similarity of simulations when compared to model predictions and observations. Tests confirmed the reliability and time efficiency of the ensemble technique, since it reproduced very well the results of a reference run, a computation based on the observed boundary conditions. For the spring-neap cycle modelled, the BSS was of 0.91 (a perfect modelling would have a BSS of 1), with a reduction in the simulation time on the order of 80%. For the 6-month-period simulation, results were also excellent: BSS=0.92 and a computer time reduction of 85%. In principle, this method has the advantage of being applied to any process-based numerical model.     

Ice flow direction during late Paleozoic glaciation in western Paraná Basin, Brazil

The recent discovery of ice-striated surfaces associated with the late Paleozoic Aquidauana Formation suggests that glaciers coming from southwest Africa reached westernmost parts of the Paraná Basin in central Brazil. Abrasion features were developed by glaciers moving from SSE towards NNW, mainly on an unconsolidated bed. These records expand to about 1,050,000 km², the coverage of the late Paleozoic glaciation in the region of the Paraná Basin in Western Gondwana.

Resumen

A recente descoberta de superfícies estriadas associadas à Formação Aquidauana, de idade permocarbonífera, sugere que as geleiras provenientes do sudoeste da África alcançaram as porções ocidentais da Bacia do Paraná, na região central do Brasil. As feições de abrasão foram geradas pelo deslocamento de geleiras de SSE para NNW, principalmente sobre substrato inconsolidado. Estes novos registros evidenciam que a glaciação neopaleozóica cobriu uma área de pelo menos de 1.050.000 km² na região ocupada pela Bacia do Paraná no Gondwana Ocidental.     

The relation between the magnitude derived from surface and from body waves for station průhonice

auam aum¶rt;, m u n¶rt; n a¶rt;u u nm a anu, umua a u mauu u 1964–1976 . ¶rt; aum¶rt; ma auau aum¶rt;, n¶rt; uu m .     

Ice-sheet growth and high-latitudes sea-surface temperature

The response of the LLN 2-D climate model to the insolation and CO₂ forcings during the Eemian interglacial is compared to reconstructions obtained from deep-sea cores drilled in the Norwegian Sea and in the North Atlantic. Both reconstructions and modeling results show a decrease of sea-surface temperature (SST) in the higher latitudes (70–75 °N zonal belt for the model and the Norwegian Sea for the proxy records), associated with a more moderate cooling at lower latitudes (50–55 °N and North Atlantic), at the middle of isotopic substage 5e, several millenia before the beginning of continental ice-sheet growth. Such a comparison between the simulated SST and ice volume of the Northern Hemisphere has been extended to the whole last glacial-interglacial cycle. The influence of the insolation forcing on SST and the shortcomings of the model due to its zonal character are discussed. Received: 6 July 1995/Accepted: 19 December 1995