Miracle-dz/UniFAR-FTUs huggingface dataset:
Anthropogenic CO2 inventory of the Indian Ocean

This study presents basin‐wide anthropogenic CO2 inventory estimates for the Indian Ocean based on measurements from the World Ocean Circulation Experiment/Joint Global Ocean Flux Study global survey. These estimates employed slightly modified ΔC* and time series techniques originally proposed by Gruber et al. [1996] and Wallace [1995], respectively. Together, the two methods yield the total oceanic anthropogenic CO2 and the carbon increase over the past 2 decades. The highest concentrations and the deepest penetrations of anthropogenic carbon are associated with the Subtropical Convergence at around 30° to 40°S. With both techniques, the lowest anthropogenic CO2 column inventories are observed south of 50°S. The total anthropogenic CO2 inventory north of 35°S was 13.6±2 Pg C in 1995. The inventory increase since GEOSECS (Geochemical Ocean Sections Program) was 4.1±1 Pg C for the same area. Approximately 6.7±1 Pg C are stored in the Indian sector of the Southern Ocean, giving a total Indian Ocean inventory of 20.3 ±3 Pg C for 1995. These estimates are compared to anthropogenic CO2 inventories estimated by the Princeton ocean biogeochemistry model. The model predicts an Indian Ocean sink north of 35°S that is only 0.61–0.68 times the results presented here; while the Southern Ocean sink is nearly 2.6 times higher than the measurement‐based estimate. These results clearly identify areas in the models that need further examination and provide a good baseline for future studies of the anthropogenic inventory.
Extensional detachment faulting on the Tyrrhenian margin of the southern Apennines contractional belt (Italy)

The tectonic evolution of the Campania margin during the late Pliocene–Pleistocene is characterized by extensional deformation coeval with the opening of the Marsili oceanic basin. The initial stages of stretching are represented in the analysed area by the development of low-angle normal faults that extended the belt in the same direction as the direction of spreading recognized for the oceanic basin. Detachment faulting was accompanied by the onset of magmatic activity and by major uplifts that resulted in the accumulation of thick conglomerate successions in the half-grabens that developed in the upper plate of the extensional detachment. Deformation continued during the Mid-Pleistocene with the formation of strike-slip and normal faults trending almost parallel to the spreading direction of the Marsili basin. These faults dissected the extensional detachment and promoted counter-clockwise block rotations about vertical axes, which accommodated the ESE-directed stretching of the Marsili basin and the consequent sinistral shear imposed on the southern Apennine chain. The development of a regional detachment fault along the Tyrrhenian margin of Campania explains the complex patterns of subsidence and uplift that characterize this area during the Pleistocene and fits well within the regional geodynamic framework of the southern Tyrrhenian Sea.
Modeling Parent and Metabolite Fate and Transport in Subsurface Drained Fields With Directly Connected Macropores 1

Abstract: Few studies exist that evaluate or apply pesticide transport models based on measured parent and metabolite concentrations in fields with subsurface drainage. Furthermore, recent research suggests pesticide transport through exceedingly efficient direct connections, which occur when macropores are hydrologically connected to subsurface drains, but this connectivity has been simulated at only one field site in Allen County, Indiana. This research evaluates the Root Zone Water Quality Model (RZWQM) in simulating the transport of a parent compound and its metabolite at two subsurface drained field sites. Previous research used one of the field sites to test the original modification of the RZWQM to simulate directly connected macropores for bromide and the parent compound, but not for the metabolite. This research will evaluate RZWQM for parent/metabolite transformation and transport at this first field site, along with evaluating the model at an additional field site to evaluate whether the parameters for direct connectivity are transferable and whether model performance is consistent for the two field sites with unique soil, hydrologic, and environmental conditions. Isoxaflutole, the active ingredient in BALANCE® herbicide, was applied to both fields. Isoxaflutole rapidly degrades into a metabolite (RPA 202248). This research used calibrated RZWQM models for each field based on observed subsurface drain flow and/or edge of field conservative tracer concentrations in subsurface flow. The calibrated models for both field sites required a portion (approximately 2% but this fraction may require calibration) of the available water and chemical in macropore flow to be routed directly into the subsurface drains to simulate peak concentrations in edge of field subsurface drain flow shortly after chemical applications. Confirming the results from the first field site, the existing modification for directly connected macropores continually failed to predict pesticide concentrations on the recession limbs of drainage hydrographs, suggesting that the current strategy only partially accounts for direct connectivity. Thirty‐year distributions of annual mass (drainage) loss of parent and metabolite in terms of percent of isoxaflutole applied suggested annual simulated percent losses of parent and metabolite (3.04 and 1.31%) no greater in drainage than losses in runoff on nondrained fields as reported in the literature.
Spatiotemporal Changes in Landscape Pattern in Response to Afforestation in Northeastern Turkey: A Case Study of Torul

Abstract Monitoring and understanding of land use/forest cover dynamics as well as the factors affecting the changes in land use/forest cover are necessary for the sustainable management of natural resources. This study analyzes the spatial and temporal changes in land use and forest cover patterns in a typical mountain forest area in the Torul State Forest Enterprise area of Northeastern Turkey. The investigation evaluates the temporal changes of the spatial structure of forest conditions through the spatial analysis of forest-cover type maps from 1984 and 2005 using GIS and FRAGSTATS. The evidence presented here showed that there were drastic changes in the temporal and spatial dynamics of land use/forest cover, and between 1984 and 2005 there was a net increase of 19.9% in total forested area. Productive forest area increased by 3161 ha, although degraded forest area increased 9216 ha. In examining the changes of crown closure and development stages of the forest ecosystem during the study period, the forest stand area with low crown closures increased. The regenerated area increased because of regeneration activities while the other development stages were left to grow to older development stages in the period. These results regarding the crown closure and development stage show that forest quality has increased, and this is partly due to emigration of the rural population in Torul. In terms of spatial configuration, the landscape structure in Torul, the State Forest Enterprise area, changed substantially over the 21-year study period, resulting in fragmentation of the landscape as indicated by large patch numbers and smaller mean patch sizes, owing to heavy timber subtraction, illegal cutting, and uncontrolled stand treatments.
Effects of a long-term fire retardant chemical (Fire-Trol 934) on seed viability and germination of plants growing in a burned Mediterranean area

This work documents the effect of a common, long-term fire retardant chemical, Fire-Trol 934, on seed viability and germination of 36 plant species growing in a burned Mediterranean area, covering different life-form types, regenerative strategies and distribution ranges. Seeds were subjected to four treatments: control, and application of Fire-Trol 934 at concentrations of 0.02, 0.2 and 2%. Fire-Trol 934 significantly decreased both seed viability and germination in the group of species studied, which suggests that Fire-Trol 934 may be toxic for seeds, at least when applied at high concentrations. Whereas seed viability generally showed a progressive decrease with increased Fire-Trol 934 concentration, germination percentages generally increased when intermediate Fire-Trol 934 concentrations were used, but tended to be drastically reduced when seeds were exposed to the highest (2%) concentration. The reduction observed in germination at the highest Fire-Trol 934 concentration was greater than that observed in viability, which suggests that the effect of Fire-Trol 934 on seeds may not be lasting. Little differences in the response to Fire-Trol 934 emerged among plant groups, all of which followed the general tendency described above.
Offsetting the radiative benefit of ocean iron fertilization by enhancing N2O emissions

Ocean iron fertilization is being considered as a strategy for mitigating the buildup of anthropogenic CO2 in the atmosphere. Assessment of this strategy requires consideration of its unintended consequences, such as an enhancement of ocean N2O emissions. This feedback could offset the radiative benefit from the atmospheric CO2 reduction significantly, because N2O is a much more powerful greenhouse gas than CO2 itself. Our model results show that the magnitude of this offsetting effect is substantial, but is highly dependent on the location and duration of fertilization. We find the largest offsets (of the order of 100%) when fertilization is undertaken in the tropics, particularly when it is of limited duration and size. Smaller, but still substantial effects are found when fertilization is undertaken elsewhere and over longer periods. These results suggest that any assessment of ocean fertilization as a mitigating option is incomplete without consideration of the N2O feedback.
Modelling large ground source cooling systems in the Chalk aquifer of central London

Abstract The Cooling the Tube Programme was set up to implement London Underground's intention to mitigate future warming of the underground system and to control tunnel temperatures. As part of this programme the use of groundwater from the Chalk in open-loop systems was considered for cooling a number of stations and a groundwater model was determined as a requirement by the Environment Agency to assess impacts on the Chalk aquifer. It seemed plausible that the plumes of injected, warmed water would interact hydraulically and possibly also thermally with each other at some locations. Furthermore, London Underground wished to investigate any longer-term warming effects and potential loss in cooling benefit. This paper provides an overview of the hydrogeological modelling approach that was adopted to assess the potential hydraulic and thermal effect of the proposed schemes and summarizes some of the findings that may be of broader interest. A staged approach was used to guide and refine the modelling. Initially, analytical solutions were used to investigate the processes of heat transport in the Chalk and to derive parameters from a field-scale test. The results indicated that, even for low fissure-to-matrix contact areas, heat is likely to be conducted far into the Chalk matrix. Over longer time scales, significant heat loss occurs into the under- and overlying formations and the available analytical solutions are of less use in scoping heat calculations for open-loop schemes at this scale. Distributed, finite-element, numerical models were constructed to simulate the interactions within groups of ground source cooling systems and to investigate specific operating conditions at single schemes. Extensive sensitivity analysis was carried out to assess the level of uncertainty in the model predictions, and the relative sensitivity to the various parameters. The greatest uncertainty was associated with detailed aspects of the conceptual model of heat flow. Model results were sensitive to the assumed vertical distribution of permeability in the Chalk. Additional uncertainty was associated with the selection of appropriate thermal boundary conditions and the extent of interaction with the under- and overlying formations. Uncertainty in the model hydraulic and thermal material parameters had less effect on the simulated performance of the systems. Operational conditions, such as the amount of heat injected and the separation of the abstraction and injection boreholes, were assessed and this paper provides some quantification of the significance of these factors. This work also demonstrates that equivalent MT3D and FEFLOW models give reasonable agreement and both approaches are feasible for modelling heat transport, as density-driven flow is not significant for the temperature differences associated with these cooling schemes.
Deep thermohaline circulation in the low‐latitude Atlantic during the Last Glacial

Present-day low-latitude eastern and western Atlantic basins are geochemically distinct below the sill depth of the Mid-Atlantic Ridge. While Antarctic Bottom Water (AABW) circulates freely in the western Atlantic, flow into the eastern Atlantic is restricted below 4 km which results in filling the abyssal depths of this basin with water of geochemical similarity to nutrient depleted North Atlantic Deep Water. Using carbon isotopes and Cd/Ca ratios in benthic foraminifera we reconstruct the geochemistry of these basins during the last glacial maximum. Results indicate that deep eastern and western Atlantic basins became geochemically identical during the last glacial. This was achieved by shoaling of the upper surface of AABW above the sill depth of the Mid-Atlantic Ridge, which allowed bottom waters in both basins to be filled with the same water mass. Although AABW became the dominant water mass in the deep eastern Atlantic basin during the glacial, Holocene-glacial δ13C-PO4 shifts in this basin are in Redfield proportions, unlike the disproportionate Holocene-glacial δ13C-PO4 shifts observed in the Southern Ocean. By examining the composition of deep and intermediate waters throughout the Atlantic, we show that this effect was induced by a change in gradient of the δ13C-PO4 deepwater mixing line during glacial times. Evidence from high-latitude planktonic data suggests that the change in gradient of the deepwater mixing line was brought about through a significant reduction in the thermodynamic effect on Southern Ocean surface waters. By using coupled δ13C-PO4 data to constrain the composition of end member water masses in the glacial Atlantic, we conclude that deep waters in the low-latitude glacial Atlantic were composed of a mixture of northern and southern source waters in a ratio of 1∶3.
Growth-Phase Thinning of the Near-Earth Current Sheet During the Cdaw-6 Substorm

The thinning of the near-Earth current sheet during the growth phase of the CDAW 6 magnetospheric substorm is studied. The expansion onset of the substorm occurred at 1054 UT, March 22, 1979. During the growth phase, two spacecraft, ISEE 1 and ISEE 2, were within the current sheet approximately 13RE from the Earth and obtained simultaneous high-resolution magnetic data at two points in the current sheet. Plasma data were also provided by the ISEE spacecraft and solar wind data by IMP 8. To facilitate the analysis, the GSM magnetic field data are transformed to a “neutral sheet coordinate system” in which the new x axis is parallel to the average magnetic field above and below the neutral sheet and the new y axis lies in the GSM equatorial plane. A model based on the assumption that the current sheet is a time-invariant structure fails to predict neutral sheet crossing times. Consequently, the Harris sheet model, which allows one to remove the restriction of time invariancy, is used instead. It is found that during the growth phase, a model parameter corresponding to the thickness of the current sheet decreased exponentially from about 5RE to 1RE with a time constant of about 14 min. In addition, the ISEE 1 and ISEE 2 neutral sheet crossings after expansion onset indicate that the neutral sheet was moving upward at 7 km/s relative to the spacecraft. Since both crossings occurred in approximately 80 s, the current sheet thickness is estimated to be about 500 km. These results demonstrate that the near-Earth current sheet undergoes dramatic thinning during the substorm growth phase and expansion onset.
Moduli and Damping Factors for Dynamic Analyses of Cohesionless Soils

Data are presented concerning the shear modulus and damping ratios of sands and gravelly soils as determined by laboratory and field tests. A simple relationship is proposed to relate the shear modulus of a cohesionless soil to a modulus stiffness coefficient, which is a soil property and depends on the characteristics of the soil, and the effective mean principal stress at any point in the soil. Values for the modulus coefficient at low strains are suggested, and it is shown that these values for sands can be estimated from the standard penetration resistance of the sand. Values for gravels are generally greater than those for sands by factors ranging from 1.35–2.5. Suggestions are also made for determining the variation of shear modulus with shear strain and the damping ratios for both sandy and gravelly soils.
Observed tidal currents outside Block Island Sound: Offshore decay and effects of estuarine outflow

[1] An array of moored profiling current meters on the inner continental shelf 15–65 m deep is used to investigate tidal currents outside the Block Island Sound and Long Island Sound estuarine system. The M2 constituent dominates due to near-resonant semi-diurnal estuarine response. Vertical-mean M2 currents rotate clockwise in time in ellipses elongated toward the estuary mouth with little sensitivity to complex local bathymetry; semi-major axes decay sharply offshore (55 to 20 cm/s over 10 km) in agreement with the nearly inverse-square radius dependence of a kinematic theory. Estimated tidal volume exchange out of Block Island Sound to the south is 2.9 × 105 m3/s. Observed vertical structure of M2 ellipses in the deepest 10–20 m (amplitude decay, ellipse flattening, major axis turning clockwise, phase advance) is generally captured well by optimally fit frictional solutions despite the fact that they omit bathymetry and include stratification only indirectly through its influence on eddy viscosity. In the upper water column, vertical structure varies seasonally: Mid-depth ellipses enlarge in spring; near-surface ellipses are larger (smaller) than optimal-fit solutions in fall/winter (spring). Observed seasonal-average estuarine outflow includes surface-intensified Coriolis-deflected mean flow that strengthens and spreads farther offshore in spring. Richardson numbers based on moored hydrographic profiler records suggest spring stratification suppresses deep eddy viscosities, which in frictional solutions can explain mid-depth ellipse enlargement. An inviscid theory for mean-flow modifications due to ambient vorticity of estuarine outflow currents is shown to be the most plausible explanation for observed seasonal changes in near-surface tidal ellipses.
A Tour of Optimisation Methods for Facies Estimation in AVO Seismic Inversion Using Markov Random Fields

We overview some joint lithology-fluid-class/rock-properties inversion techniques for AVO/quantitative-interpretation work from true-amplitude imaged seismic data, using a Bayesian hierarchical model. We use a Markov random-field (MRF) model for facies labels, and a facies-conditional Normal model for elastic rock properties. The MRF forces spatial smoothness in categories, and forbids non-hydrodynamical fluid-class transitions. The rock properties model captures loading effects and mutual correlation between elastic variables within a facies. We study the optimisation problem rather than sampling. The optimisation is a mixed integer-continuous problem, provably NP-hard, but susceptible to good heuristics in certain regimes we discuss. A natural approach to the problem is the EM algorithm, which provides fast local solutions using loopy-belief propagation for the E-step and conjugate-gradient least-squares for the M-step. This yields soft/marginalised estimates of facies labels. Industry-standard Bayesian classifications are related to single cycles of this EM algorithm, but without spatial coupling. A comparable method to the EM algorithm is "relaxed joint inversion'' with continuous "facies indicator'' variables confined to a simplex. The absence of middle frequencies and the multimodality of the objective make gradient methods, including EM and relaxation, vulnerable to local minima. Two globalising approaches, deterministic annealing, and integer-optimisation, are discussed.
Detection of small IR objects using wavelets, matched subspace detectors, and registration

Infrared sensors and advanced signal processing are used to detect small (or point) targets in highly cluttered and noisy environments. In this paper, a wavelet detection algorithm and tracking of small targets in clutter will be discussed. A new registration algorithm based on optical flow estimates with matched subspace detectors against small maneuverable targets is also discussed. Both detectors incorporate adaptive constant false alarm rate (CFAR) detection statistics. Simulation of the detection and tracking algorithms using an unclassified database with a helicopter target and platform for the video cameras is summarized.
Biot‐type scattering effects in gas hydrate‐bearing sediments

[1] This paper studies the energy conversions that take place at discontinuities within gas hydrate-bearing sediments and their influence on the attenuation of waves traveling through these media. The analysis is based on a theory recently developed by some of the authors, to describe wave propagation in multiphasic porous media composed of two solids saturated by a single-phase fluid. Real data from the Mallik 5L-38 Gas Hydrate Research well are used to calibrate the physical model, allowing to obtain information about the characteristics of the cementation between the mineral grains and gas hydrates for this well. Numerical experiments show that, besides energy conversions to reflected and transmitted classical waves, significant fractions of the energy of propagating waves may be converted into slow-waves energy at plane heterogeneities within hydrated sediments. Moreover, numerical simulations of wave propagation show that very high levels of attenuation can take place in the presence of heterogeneous media composed of zones with low and high gas hydrate saturations with sizes smaller or on the order of the wavelengths of the fast waves at sonic frequencies. These attenuation levels are in very good agreement with those measured at the Mallik 5L-38 Gas Hydrate Research Well, suggesting that these scattering-type effects may be a key-parameter to understand the high sonic attenuation observed at gas hydrate-bearing sediments.
Potential Predictability of the North Atlantic Heat Transport Based on an Oceanic State Estimate

AbstractThis paper investigates the potential predictability of the meridional heat transport (MHT) in the North Atlantic on interannual time scales using hindcast ensembles based on an oceanic data assimilation product. The work analyzes the prognostic potential predictability (PPP), using the ocean synthesis of the German partner of the consortium for Estimating the Circulation and Climate of the Ocean (GECCO) as initial conditions and as boundary conditions. The PPP of the MHT varies with latitude: local maxima are apparent within the subpolar and the subtropical gyres, and a minimum is apparent at the boundary between the gyres. This PPP minimum can also be seen in the PPP structure of the Atlantic meridional overturning circulation (AMOC), although it is considerably less pronounced. The decomposition of the MHT shows that within the subpolar gyre, the gyre component of the MHT influences the PPP structure of the MHT. Within the subtropical gyre, the overturning component of the MHT characterizes the.