Miracle-dz/UniFAR-FTUs huggingface dataset:
Regional-scale surface flux observations across the boreal forest during BOREAS

A major role of the National Center for Atmospheric Research (NCAR) Electra aircraft during the Boreal Ecosystem-Atmosphere Study (BOREAS) was to measure fluxes of momentum, sensible and latent heat, carbon dioxide, and ozone on a transect that crossed the entire boreal forest biome. The observations spanned the growing season (late May to mid-September 1994) and extended the fluxes obtained in two intensive study areas to larger spatial scales to help provide a data set that is useful for comparison with and validation of large-scale models and satellite retrievals. We found the deciduous forests to be more photosynthetically active than nearby coniferous forests. Coniferous forest fluxes across the transect from the BOREAS southern to northern study areas show no apparent spatial trend, though smaller-scale variability is large. The fluxes make a smooth transition from the BOREAS northern study area to the subarctic tundra. Typical midsummer, midday, large-scale net ecosystem exchanges of carbon dioxide were about -10 μmol m -2 s -1 for primarily deciduous forests, about -6 μmol m -2 s -1 for the primarily coniferous regions between and including the two BOREAS study areas, and about -2 μmol m -2 s -1 for the subarctic tundra. The first two values are similar to those observed by flux towers in the region. Throughout the boreal forest the fluxes are influenced by the presence of lakes. Lake fraction is found to be a dominant source of variability in the fluxes observed along the transect. Lakes are also found to be large sinks of available radiant energy. Regional ground storage of heat is estimated to be about 30% of the net radiation over the forest, and 40% over the subarctic tundra, largely due to the presence of lakes.
The origin and development of the Nyl River floodplain wetland, Limpopo Province, South Africa: trunk–tributary river interactions in a dryland setting

The Nyl River floodplain wetland, one of South Africa's largest floodplain wetlands and a Ramsar site of international conservation importance, is located in an area of long-term and still active valley sediment accumulation. Creation of accommodation space for sedimentation has previously been attributed to tectonic controls, but new investigations reveal that a more likely cause is progradation of coarse-grained tributary fans across the narrow river valley downstream of the main area of floodplain wetland. Obstruction of trunk river flow and sediment transfer by these tributary fans has led to backponding and upstream gradient reduction and to accumulation of valley fills up to ∼35 m thick. Chronological control for the timing and rate of sediment accumulation is limited, but we hypothesise that a semi-arid to arid climate, characterised by asynchronous trunk–tributary activity that results in marked discontinuities in downstream water and sediment transfer, is likely to have been a key control. These interpretations are supported by other studies of dryland rivers globally and the findings add to our growing understanding of the controls on the origin and development of southern African wetlands, particularly by demonstrating how the combination of a particular physiography and a dryland climate can impart some distinctive geomorphological characteristics.
Drained creep of undisturbed cohesive marine sediments

Long-term, drained triaxial creep and direct simple shear creep tests were conducted on undisturbed marine specimens from the Gulf of Mexico and the north-central Pacific. Results indicated that time-dependent deformations can be represented by a power law equation, and the creep strain rate can be represented by an equation similar to that suggested earlier by other researchers. However, it was found that the m parameter suggested by these scientists was not a constant but dependent on stress level and sediment plasticity. Ageing effects were evidenced in triaxial specimens by the increase of shear strength with both test duration and stress level. The results provided a guide for the development of mathematical stress–strain–time relationships that will be developed in a separate paper. Key words : drained triaxial creep, simple shear creep, stress–strain–time behavior.
Age and origin of upland block fields on melville peninsula, eastern canadian arctic

Block fields have developed on gently graded uplands of granite and gneiss on central and southern Melville Peninsula. The location of block fields is not controlled by elevation, but rather by areas covered by cold–based ice during the last glaciation. Block fields consist either of angular boulders, sorted circles 3–4 m across having blocky rims and central areas of weathered grus, concentrations of openwork boulders, or in the southeast, of immature bouldery till. The block fields are primarily relict features predating the last glaciation, produced by weakening of bedrock by weathering along joints, followed by frost heave, although some block fields have been modified by meltwater from regional glacier down–wasting. Frost processes are active in the modern environment but the extent of riven bedrock and the size of recent patterned ground forms on postglacial surfaces are insufficient to account for the forms in the block fields.
History of research on the geology and palaeontology of the Rhynie area, Aberdeenshire, Scotland

ABSTRACT Geological and palaeontological research in the Rhynie area, Aberdeenshire, Scotland, has progressed in several stages. Following early surveys in the nineteenth century, Dr William Mackie mapped the western margin of the basin in 1910–1913, and discovered the plant-bearing chert. Following trenching of the chert in 1913, Kidston & Lang described the plant fossils between 1917 and 1921 and Scourfield, Hirst and Maulik the arthropods in the 1920s. Following a ‘dark age’ of some 30 years, Geoffrey Lyon awakened interest in the late 1950s. Trenching in 1963–1971 provided Lyon and his co-workers with new material, and resulted in finds of new plants and reinterpretations of earlier work. The next phase was initiated by Winfried Remy's discovery of gametophytes in material given to him by Lyon. Since 1980, the Münster school has continued to make exciting discoveries. Aberdeen University involvement began in 1987 with geochemical work confirming a hot spring origin for the chert. Drill cores taken in 1988 and 1997, and further trenching have allowed structural, sedimentological and stratigraphic reappraisals, and resulted in the discovery of a new biota in the Windyfield chert. Long-term collaborative international research continues to advance interpretation of this unique Early Devonian hot spring system, and the remarkably diverse freshwater and terrestrial biota of the cherts.
Relative impact of windblown dust versus anthropogenic fugitive dust in PM2.5 on air quality in North America

[1] A new windblown dust emissions module was recently implemented into A Unified Regional Air Quality Modeling System (AURAMS), a Canadian regional air quality model, to investigate the relative impact of windblown dust versus anthropogenic fugitive dust on air quality in North America. In order to apply the windblown dust emissions module to the entire North American continent, a soil grain size distribution map was developed using the outputs of 4 monthly runs of AURAMS for 2002 and available PM2.5 dust content observations. The simulation results using the new soil grain size distribution map showed that inclusion of windblown dust emissions is essential to predict the impact of dust aerosols on air quality in North America, especially in the western United States. The windblown dust emissions varied widely by season, whereas the anthropogenic fugitive dust emissions did not change significantly. In the spring (April), the continental monthly average emissions rate of windblown dust (4.1 × 107 kg/d) was much higher than that of anthropogenic fugitive dust (1.5 × 107 kg/d). The total amount of windblown dust emissions in North America predicted by the model for 2002 was comparable to that of anthropogenic fugitive dust emissions. Even with the inclusion of windblown dust emissions, however, the model still had difficulty simulating dust concentrations. Further improvements are needed, in terms of both limitations of the windblown dust emission module and uncertainties in the anthropogenic fugitive dust emissions inventories, for improved dust modeling.
Cold shock domain proteins and glycine-rich RNA-binding proteins from Arabidopsis thaliana can promote the cold adaptation process in Escherichia coli

Despite the fact that cold shock domain proteins (CSDPs) and glycine-rich RNA-binding proteins (GRPs) have been implicated to play a role during the cold adaptation process, their importance and function in eukaryotes, including plants, are largely unknown. To understand the functional role of plant CSDPs and GRPs in the cold response, two CSDPs (CSDP1 and CSDP2) and three GRPs (GRP2, GRP4 and GRP7) from Arabidopsis thaliana were investigated. Heterologous expression of CSDP1 or GRP7 complemented the cold sensitivity of BX04 mutant Escherichia coli that lack four cold shock proteins (CSPs) and is highly sensitive to cold stress, and resulted in better survival rate than control cells during incubation at low temperature. In contrast, CSDP2 and GRP4 had very little ability. Selective evolution of ligand by exponential enrichment (SELEX) revealed that GRP7 does not recognize specific RNAs but binds preferentially to G-rich RNA sequences. CSDP1 and GRP7 had DNA melting activity, and enhanced RNase activity. In contrast, CSDP2 and GRP4 had no DNA melting activity and did not enhance RNAase activity. Together, these results indicate that CSDPs and GRPs help E.coli grow and survive better during cold shock, and strongly imply that CSDP1 and GRP7 exhibit RNA chaperone activity during the cold adaptation process.
The use of fish remains in sediments for the reconstruction of paleoproductivity

The majority of the works concerning fish productivity are based in fish landing records. However, in order to understand the causes of variability in fish productivity (natural and/or anthropogenic) it is essential to have information from periods when human impacts (e.g., fisheries) are considered unimportant. This can be achieved through the use of fish remains, i.e. scales, vertebrae and otoliths, from sediment records. The obtained data can be used to develop time series of fish stocks revealing the history of fish population dynamics over the last centuries or millennia. The majority of these works are located in Eastern Boundary Current Systems (e.g., Benguela, Peru-Humboldt, California), because these are associated with coastal upwelling and high productivity, which in some cases is at the origin of low bottom oxygen levels, leading to scale preservation. A search for fish remains in the Portuguese margin sediments is in progress in the context of the ongoing research project POPEI (High-resolution oceanic paleoproductivity and environmental changes; correlation with fish populations), which intend to fill the gap in studies of this type for the Canary Current System. In this paper we review some general ideas of the use of fish remains, related studies, methodologies and data processing, as well as presenting the first results of POPEI.
Données Nouvelles sur la Présence d'un Pergélisol en Aquitaine au cours des Dernières Glaciations

Les formes cryergiques identifiees en Aquitaine montrent que cette region de France a vraisemblablement ete affectee par le developpement d'un pergelisol. Celui-ci se serait manifeste au cours de deux episodes climatiques distincts: l'un daterait de la partie superieure du dernier Pleniglaciaire (Dryas ancien); l'autre, plus hypothetique, se situerait dans la deuxieme moitie de l'avant dernier Glaciaire. Le type de ces pergelisols ne peut etre defini avec une totale certitude. Par rapport a l'actuel, la baisse de temperature moyenne annuelle de l'air peut etre estimee entre 13 et 19°C.
Impact assessment of climatic and land-use changes on flood runoff in southeast Queensland

Abstract Over the past century, land-use has changed in southeast Queensland, and when coupled with climatic change, the risk of flooding has increased. This research aims to examine impacts of climate and land-use changes on flood runoff in southeast Queensland, Australia. A rainfall–runoff model, RORB, was calibrated and validated using observed flood hydrographs for one rural and one urbanized catchment, for 1961–1990. The validated model was then used to generate flood hydrographs using projected rainfall based on two climate models: the Geophysical Fluid Dynamics Laboratory Climate Model 2.1 (GFDL CM2.1) and the Conformal-Cubic Atmospheric Model (CCAM), for 2016–2045. Projected daily rainfall for the two contrasting periods was used to derive adjustment factors for a given frequency of occurrence. Two land-use change scenarios were used to evaluate likely impacts. Based on the projected rainfall, the results showed that, in both catchments, future flood magnitudes are unlikely to increase for large flood events. Extreme land-use change would significantly impact flooding in the rural catchment, but not the urbanized catchment. Editor Z.W. Kundzewicz; Associate editor Y. Gyasi-Agyei
Coupled groundwater flow and solute transport with fluid density strongly dependent upon concentration

The governing equations are discussed for the flow of salt solution with significant density variations through a porous medium. Equations for mass conservation, salt conservation, and momentum conservation are formulated in terms of the mass fraction weighted average velocity and the mass fraction of concentrated salt solution, and the underlying approximations are considered. These equations are incorporated in the finite element groundwater code NAMMU and applied to test case 5 of level 1 of the international HYDROCOIN project. This test case proposed to model the groundwater flow over a hypothetical salt dome. The nonlinearities arising from the density variation and from a velocity-dependent dispersion tensor made the problem very hard: we had to use special techniques including mixed interpolation finite elements and parameter stepping. Starting from a related problem involving a large diffusivity we obtained a series of solutions at successively smaller values of dispersion. Our final solution is to a physically realistic problem very similar to that specified. We draw general conclusions relevant to modeling these flows and have built confidence in our numerical code.
EVALUATION OF THE FIELD PERCOLATION TEST AND AN ALTERNATIVE PROCEDURE TO TEST SOIL POTENTIAL FOR DISPOSING OF SEPTIC TANK EFFLUENT

FOUR FIELD TESTS WERE APPLIED IN WELL DRAINED PEDONS IN WISCONSIN. INFILTRATION RATES OF THE VARIABLE-HEAD PERCOLATION TEST PROCEDURE, REQUIRED BY LAW IN MANY STATES TO TEST SOIL SUITABILITY FOR DISPOSAL OF SEPTIC TANK EFFLUENT, WERE MUCH HIGHER AND MORE VARIABLE THAN HYDRAULIC CONDUCTIVITY (K) FOR SATURATED SOIL, MEASURED WITH THE DOUBLE-TUBE METHOD. SOIL MOISTURED TENSIONS WERE RECORDED AROUND OPERATING, PARTLY FILLED, SEEPAGE BEDS IN DIFFERENT SOILS INDICATING THE OCCURRENCE OF LOW FLOW RATES THROUGH UNSATURATED SOIL, DUE TO CRUSTING AT THE SOIL INTERFACE OF THE SEEPAGE BEDS. MEASUREMENT OF K VALUES IN SITU, AS A FUNCTION OF SOIL MOISTURE TENSION, IS PROPOSED AS A FIELD TEST TO DETERMINE SOIL POTENTIAL FOR EFFLUENT DISPOSAL. A FIELD EXPERIMENT WITH DOSING OF EFFLUENT WAS MADE TO DEMONSTRATE THAT SYSTEM MANAGEMENT WILL DETERMINE FLOW SYSTEM AT ANY GIVEN TIME. /AUTHOR/
Climatic or anthropogenic alluviation in Central European valleys during the Holocene?

Abstract Traces of increased river activity during the Late Glacial and Holocene can be identified in the river valleys of central Europe. This activity includes changes of river channel pattern and changes in the type and rate of floodplain sedimentation. A model of the sequence of events within a phase of increased river activity has been constructed as part of a detailed study of the Vistula valley. This analysis indicated that the evolution of the Vistula river valley has resulted primarily from climatic factors, although local factors (including human modification) contributed to the magnitude of changes which had already developed as a result of climatic controls.
On the NO2 + soot reaction in the atmosphere

Recent modeling studies have suggested that soot is a key component of tropospheric chemistry in remote regions, acting to reduce HNO3 to NO2 and possibly NO2 to NO. It may be expected then that soot also affects the chemistry of rural and urban areas, where soot concentrations are typically several orders of magnitude higher than in the remote troposphere. In order to test this assumption, a modeling study was conducted for typical urban and rural areas, with the same HNO3/NO2/soot chemistry proposed in the previous modeling studies of the remote troposphere. Unreasonable results were found (e.g., nearly total suppression of urban ozone, in contradiction to common observations), suggesting that the NO2/soot reaction was considerably overestimated in previous modeling studies. Therefore the NO2/soot chemistry was reconsidered. A new preliminary mechanism is suggested, based on recent laboratory studies of this reaction. Results show that the NO2/soot reaction does not notably affect the Ox-NOx-HOx chemistry of the lower continental troposphere, except maybe during nighttime in urban environments. A potential contribution of the NO2/soot interaction to HONO production is noted.
Mechanisms for Forming Discontinuity Surfaces Within Shoreface–shelf Parasequences: Sea Level, Sediment Supply, or Wave Regime?

Abstract A 2D process–response model was used to evaluate potential mechanisms involved in the formation of small-scale stratigraphic variability that is observed within progradational wave-dominated shoreface–shelf parasequences. Model experiments, which are based on scenarios that consist of a 25 ky progradational phase, suggest that discontinuity surfaces form when either sediment supply or sea level fall rapidly, or when wave-height regime increases over relatively short time periods (102–104 y) during coastal progradation. In these cases, mean deposition rate near the lower-shoreface drops, which, combined with coastal progradation, results in a discontinuity surface. Both observed and simulated discontinuity surfaces form predominantly in lower shoreface deposits and bound meter-scale stratigraphic cycles. Simulations show that wave-regime variability affects the shoreface–shelf to a much greater depth than minor sea-level change. Therefore, facies shifts along wave climate-induced bounding surfaces occur over wider reaches of the shoreface–shelf system than sea-level-induced facies shifts. High-frequency variability in sediment supply rate results in the formation of discontinuity surfaces across which there are no distinct facies shifts.
One dimensional consolidation under cyclic loading

Abstract When cyclic loads are applied to the soil, the deformation may increase significantly depending upon the magnitude of load and nature of soil. Cyclic loads such as those induced by traffic on motorways and railways, ocean waves are long-term, sometimes including drainage during or after cyclic loading, resulting consolidation. Analytical solutions for one-dimensional consolidation of saturated cohesive soil are available under slow cyclic loading where pore water pressure builds up during loading and dissipates during unloading. In the proposed paper, an analytical solution for one-dimensional consolidation under rapid long term cyclic loading has been developed. It has been found that rate of consolidation is faster and stable condition is reached earlier in comparison with the monotonic loading.
Adoption decision and use intensity of soil and water conservation measures by smallholder subsistence farmers in Dedo District, Western Ethiopia

Soil degradation in the highlands of Ethiopia is a serious problem that threatens the sustainability of agriculture. Although efforts have been made to develop and promote several soil conservation technologies, their adoption has not been widespread. This study, based on responses from a sample of 101 households which operate on 204 plots in Western Ethiopia, interviewed in 2003 cropping year, employed a Tobit model to identify the main factors influencing farmers' decision to adopt and intensify the use of improved and indigenous soil and water conservation (SWC) measures. The results suggest that area of cultivated land, land/labour ratio, age and education level of household head and distance of the plot from home and slope of the plot provided statistically adequate predictive power on the use and intensity of SWC measures. These results are discussed and their implications for conservation programs are presented in the conclusion. Copyright © 2006 John Wiley & Sons, Ltd.
Impacts of climate change on air pollution levels in the Northern Hemisphere

So far reduction of the anthropogenic emissions of chemical species to the atmosphere has been profoundly investigated. However, new research indicates that climate change also has a significant impact on the future air pollution levels. In the Department of Atmospheric Environment, National Environmental Research Institute, Aarhus University, Denmark, a model system that is able to describe possible impacts of climate change on air pollution levels in the future has been established. By using this system the fate of a selected number of chemical species is inspected with respect to climate change. The model system consists of a coupled Atmosphere-Ocean General Circulation Model and a full 3D Chemical long-range Transport Model. The climate model provides future meteorology for selected time slices in the 21st century as wells as for a validation period in the 1990's. These data are used as input to the Chemical long-range Transport Model that includes the emission, atmospheric transport and chemical transformation and removal of more than 60 different chemical species. In order to study the impact of the changing climate alone, the anthropogenic emissions of primary pollutants are held constant at the 1990 level, while the natural biospheric emission is based on information on current land use and the predicted environmental conditions. First results from this study have been published in Atmospheric Chemistry and Physics in 2008. The absolute dominating impact from climate change on a large number of the chemical species is found to be the predicted temperature increase. The atmospheric temperature is by the climate model predicted to increase 2-3 °C on a global average with local maxima in the Arctic of 11 °C. As a consequence of this temperature increase, the temperature dependent biogenic emission of isoprene is predicted to increase significantly over land in the current model system. This leads to an increase in the ozone production and in the number of free OH radicals. This again leads to a significant change in the typical life times of many species, since the hydroxyl radicals are participating in a large number of chemical reactions. It is e.g. found that more sulphate and nitrate will be present in the future over the already polluted areas and this increase can be explained by an enhancement in the conversion of sulphur to sulphate. This study is only in the beginning of an accelerating research field with focus on the impact of climate change on air pollution. The main conclusions are that it is scientifically sound to run a chemical transport model on climate data and that the predicted temperature increase seems to have a dominating effect on the future air pollution levels and distributions. The level of several air pollution components are seen to increase in a future warmer climate. industrial climate-chemistry from the anthropogenic emissions have been for results show that it is important also to account for the impacts of climate change on future air pollution levels and