Miracle-dz/UniFAR-FTUs huggingface dataset:
Absolute versus temporal anomaly and percent of saturation soil moisture spatial variability for six networks worldwide

The analysis of the spatial‐temporal variability of soil moisture can be carried out considering the absolute (original) soil moisture values or relative values, such as the percent of saturation or temporal anomalies. Over large areas, soil moisture data measured at different sites can be characterized by large differences in their minimum, mean, and maximum absolute values, even though in relative terms their temporal patterns are very similar. In these cases, the analysis considering absolute compared with percent of saturation or temporal anomaly soil moisture values can provide very different results with significant consequences for their use in hydrological applications and climate science. In this study, in situ observations from six soil moisture networks in Italy, Spain, France, Switzerland, Australia, and United States are collected and analyzed to investigate the spatial soil moisture variability over large areas (250–150,000 km2). Specifically, the statistical and temporal stability analyses of soil moisture have been carried out for absolute, temporal anomaly, and percent of saturation values (using two different formulations for temporal anomalies). The results highlight that the spatial variability of the soil moisture dynamic (i.e., temporal anomalies) is significantly lower than that of the absolute soil moisture values. The spatial variance of the time‐invariant component (temporal mean of each site) is the predominant contribution to the total spatial variance of absolute soil moisture data. Moreover, half of the networks show a minimum in the spatial variability for intermediate conditions when the temporal anomalies are considered, in contrast with the widely recognized behavior of absolute soil moisture data. The analyses with percent saturation data show qualitatively similar results as those for the temporal anomalies because of the applied normalization which reduces spatial variability induced by differences in mean absolute soil moisture only. Overall, we find that the analysis of the spatial‐temporal variability of absolute soil moisture does not apply to temporal anomalies or percent of saturation values.
El Niño–Southern oscillation and the climate, ecosystems and rivers of Amazonia

The El Niño–Southern Oscillation (ENSO) phenomenon is one of the dominant drivers of environmental variability in the tropics. In this study, we examine the connections between ENSO and the climate, ecosystem carbon balance, surface water balance, and river hydrology of the Amazon and Tocantins river basins in South America. First we examine the climatic variability associated with ENSO. We analyze long‐term historical climate records to document the “average” climatic signature of the El Niño and La Niña phases of the ENSO cycle. Generally speaking, the “average El Niño” is drier and warmer than normal in Amazonia, while the “average La Niña” is wetter and cooler. While temperature changes are mostly uniform through the whole year and are spatially homogeneous, precipitation changes are stronger during the wet season (January‐February‐March) and are concentrated in the northern and southeastern portions of the basin. Next we use a land surface/ecosystem model (IBIS), coupled to a hydrological routing algorithm (HYDRA), to examine how ENSO affects land surface water and carbon fluxes, as well as changes in river discharge and flooding. The model results suggest several responses to ENSO: (1) During the average El Niño, there is an anomalous source of CO2 from terrestrial ecosystems, mainly due to a decreased net primary production (NPP) in the north of the basin. There is also a decrease in river discharge along many of the rivers in the basin, which causes a decrease in flooded area along the main stem of the Amazon. (2) During the average La Niña, there is an anomalous sink of CO2 into terrestrial ecosystems, largely due to an increase in NPP in the northern portion of the basin. In addition, there is a large increase in river discharge in the Amazon basin, especially from the northern and western tributaries. There is a corresponding increase in flooded area, largely in the northern rivers. These results illustrate that changes in water and carbon balance associated with ENSO have complex, spatially heterogeneous features across the basin. This underscores the need for comprehensive analyses, using long‐term observational data and model simulations, of regional environmental systems and their response to climatic variability.
Glaciers in the Arctic

Contains a compilation of literature and available data on arctic glaciers, originally prepared for Encyclopedia Arctica in 1949, and brought up to date. Ahlmann's morphological classification of glaciers is given, and the distribution, area, volume, and present regime of the glaciers is described. Regional treatment follows: Greenland, Iceland, Jan Mayen, Svalbard, Novaya Zemlya, Zemlya Frantsa-Iosifa, Severnaya Zemlya, also other small Siberian islands, are considered in turn, and their glaciers characterized; similarly: Scandinavia, the Urals and continental Siberia, continental Canada and Alaska, also Ellesmere, Baffin and Bylot, Devon, Axel Heiberg, Meighen, and Melville Islands in the Canadian Arctic Archipelago.
Interpretable Probabilistic Price Forecasting for Energy Markets

Market participants in an electricity market rely on day-ahead price forecasting to optimize and plan their bidding strategy. Highly reliable and precise price forecasting algorithms are therefore crucial for market participants. In addition to being precise and reliable, algorithms that are interpretable while also able to quantity the uncertainty will add additional benefits to the downstream bidding planning algorithms that aim to optimize the profit. In this work, we present an interpretable, probabilistic price forecasting method that is able to provide accurate price forecasts along with probabilistic estimates in the form of quantiles, while also being interpretable by detecting patterns in the historical data. The detected patterns uncover trends, seasonality in the price time series and allow correlating inter-and intra-series correlations of both lagged and future regressors, and can also interpret effects of holidays and events to the forecasted price. We demonstrate the validity and performance of our algorithm on two real world use cases by performing price forecasting of the Californian and Midcontinental energy markets in the United States.
A pore network model study of the fluid‐fluid interfacial areas measured by dynamic‐interface tracer depletion and miscible displacement water phase advective tracer methods

Fluid‐fluid interfacial areas in porous media are of considerable interest due to the impact they have on a wide range of practical applications involving mass transfer between phases, as well as for their importance in understanding unsaturated and multiphase flow behaviors in porous media. Tracer methods provide a low‐cost experimental approach for determining interfacial areas in porous media. Although a number of different tracer methods have been developed, uncertainty remains as to exactly what areas they measure. The work presented here uses pore network model simulations to study the behavior of tracers during simulated tracer measurements for two different specific water‐phase tracer methods: the dynamic‐interface tracer depletion method and the miscible displacement tracer method. The hypothesis driving this work was that different tracer methods likely measure different areas as a result of the very different ways tracers are used. Experimental data sets for six different porous media were used to validate the model and provide comparison with model‐simulated tracer‐based area measurements. Results of the work suggest that areas measured using the dynamic‐interface tracer depletion method closely match total fluid‐fluid interfacial areas, as long as the extent of tracer depletion during the method is relatively small. However, areas measured with the miscible displacement method likely fall somewhere between capillary and total fluid‐fluid areas. Calculations conducted with realistic diffusion coefficients and film thicknesses indicate that diffusion and head‐driven flow in films are insufficient to allow significant tracer access to film area, suggesting the potential importance of other mechanisms. Calculations conducted as a part of the work suggest that Leverett estimates of maximum area formed during drainage may be closer to total areas than previously reported.
Modelling socio-hydrological systems: a review of concepts, approaches and applications

Interactions between humans and the environment are occurring on a scale that has never previously been seen; one environmental facet that has seen particular co-evolution with society is water. The ::: the : scale of human interaction with the water cycle, along with the coupling present between social and hydrological systems, means that decisions that impact water also impact people. Models are often used to assist in decision-making regarding hydrological systems, and so in 5 order for effective decisions to be made regarding water resource management, these interactions and feedbacks should be accounted for in models used to analyse systems in which water and humans interact. This paper reviews literature surrounding aspects of socio-hydrological modelling. It begins with background information regarding the current state of socio-hydrology as a discipline, before covering reasons for modelling and potential applications. Some important concepts 10 that underlie socio-hydrological modelling efforts are then discussed, including ways of viewing socio-hydrological systems, space & time in modelling, complexity, data and model conceptualisation. Several modelling approaches are described, the stages in their development detailed and their applicability to socio-hydrological cases discussed. Gaps in research are then highlighted to guide directions for future research. The review of literature suggests that the nature of socio-hydrological 15 study, being interdisciplinary, focusing on complex interactions between human and natural systems, and dealing with long horizons, is such that modelling will always present a challenge; it is, however, the task of the modeller to use the wide range tools afforded to them to overcome these challenges as much as possible. The focus in socio-hydrology is on understanding the human-water system in a holistic sense, which differs from the problem solving focus of other water management fields, and 20 as such models in socio-hydrology should be developed with a view to gaining new insight into these dynamics. There is an essential choice that socio-hydrological modellers face in deciding between
On surface energy balance over the northern wetlands: 1. The effects of small‐scale temperature and wetness heterogeneity

A model is presented to calculate the surface energy balance over land surfaces covered by alternating small-scale dry-warm and wet-cool patches, as might be found on northern wetlands during summer days. The model considered the effect of local heat advection, which is responsible for reallocation of a portion of surface available energy between the patches, in addition to the spatial change in primary partition of available energy between sensible and latent heat fluxes due to different physical characteristics of the patches. The modeled results showed that neglecting the effect of local heat advection could cause significant errors in calculations of both local and cumulatively regional surface heat and moisture fluxes. The predicted errors ranged up to 200% for evaporation and 67% for Bowen ratio when dry and wet patches are small and unequal in size, or up to about 35% for evaporation and 47% for Bowen ratio when dry and wet patch sizes are equal. Patch sizes with estimated nonnegligible error, i.e., with dimensions less than 100 to 200 m, are not uncommon in northern wetlands. This suggests that the currently used surface schemes (for mesoscale and global circulation models) should incorporate the effect of local heat advection for complete consideration of the sub-grid-scale surface heterogeneity, in order to improve their applicability to landscapes like northern wetlands. As a consequence the improvement of image resolution in aircraft and satellite remote sensing technology, for identification of sub-grid small-scale surface heterogeneity, seems necessary for accurate determination of surface heat and moisture flux distributions.
The Stability of the Normal State of Superconductors in the Presence of Electric Currents

The stability of the normal state of superconductors in the presence of electric currents is studied in the large domain limit. The model being used is the time-dependent Ginzburg–Landau model, in the absence of an applied magnetic field, and with the effect of the induced magnetic field being neglected. We find that if the current is nowhere perpendicular to the boundary, or if the minimal current on the boundary, at points where it is perpendicular to it, is greater than the critical current in the one-dimensional case, then the normal state is stable. We also prove some short-time instability when the current is both perpendicular to the boundary and smaller than the one-dimensional critical current.
Identifying and Resolving Low Frequency Oscillations in Power Systems: An Illustrative Real-World Study with Practical Considerations

This paper presents a six-step procedure to identify and resolve low frequency electromechanical oscillations in power systems using small signal analysis tools. A real-world study is used to illustrate this procedure. Included are practical considerations, generally accepted analysis assumptions, and good engineering practices that beginners in this area may find useful when conducting these types of studies. The paper also shows that the common solution of installing power system stabilizers for damping low frequency oscillations may not always be the most effective solution. Using the concepts of mode shape and participation factors, the most effective solution for improving damping of a particular mode can be developed.
Imaging shallow objects and heterogeneities with scattered guided waves

Current surface seismic reflection techniques based on the common‐midpoint (CMP) reflection stacking method cannot be readily used to image small objects in the first few meters of a weathered layer. We discuss a seismic imaging method to detect such objects; it uses the first‐arrival (guided) wave, scattered by shallow heterogeneities and converted into scattered Rayleigh waves. These guided waves and Rayleigh waves are dominant in the shallow weathered layer and therefore might be suitable for shallow object imaging. We applied this method to a field data set and found that we could certainly image meter‐size objects up to about 3 m off to the side of a survey line consisting of vertical geophones. There are indications that cross‐line horizontal geophone data could be used to identify shallow objects up to 10 m offline in the same region.
Magmatic segmentation of the northern Knipovich Ridge: Evidence for high‐pressure fractionation at an ultraslow spreading ridge

The ultraslow spreading Knipovich Ridge shows axial topographic highs that are associated with off‐axis linear arrays of seamounts that parallel the spreading direction. These linear arrays suggest that the segmentation has been stable for at least 7–8 m.y. Axial topographic highs are marked with distinct gravity anomalies, suggesting that they represent thicker crust and hence volcanic segment centers. Dredging on the northern Knipovich Ridge between 76°30′ and 77°50′N shows that the axial and off‐axial seamounts, and the deeper axial rift valley between the segment centers, are composed of volcanic rocks. The basalts are subdivided into high‐, intermediate‐, and low‐FeO groups. Low‐FeO basalts, with generally more enriched radiogenic isotope ratios and REE patterns, were only dredged midway between segment centers, whereas dredges close to the segment centers comprised high‐ and intermediate‐FeO basalts. The variations in isotopes and REE patterns suggest that the mantle below the northern Knipovich Ridge is heterogeneous, and the along‐axis variations can be explained by higher degrees of melting of this heterogeneous source close to segment centers. The high‐ and intermediate‐FeO basalts define different MgO‐FeO liquid lines of descents that may reflect differences in the crystallization pressures or the water contents of the magmas. Similar water contents of the high‐ and intermediate‐FeO basalts suggest that the differences in FeO primarily are a pressure effect and that the intermediate‐FeO group fractionated at higher pressure than the high‐FeO group. The high‐FeO basalts show both low‐ and high‐pressure phenocryst assemblages, suggesting crystallization at high pressures (6–7 kbar) followed by shallow, low‐pressure fractionation. On the basis of the new data we propose that magmas at this ultraslow spreading ridge fractionate at mantle depth, except at segment centers where magma productivity occasionally is high enough to sustain shallow level magma reservoirs.
A global black carbon aerosol model

A global inventory has been constructed for emissions of black carbon from fossil fuel combustion and biomass burning. This inventory has been implemented in a three-dimensional global transport model and run for 31 model months. Results for January and July have been compared with measurements taken from the literature. The modeled values of black carbon mass concentration compare within a factor of 2 in continental regions and some remote regions but are higher than measured values in other remote marine regions and in the upper troposphere. The disagreement in remote regions can be explained by the coarse grid scale of the model (10° × 10°), the simplicity of the current deposition scheme, and possibly too much black carbon being available for transport, which would also account for the disagreement in the upper troposphere. The disagreement may also be due to problems associated with the measurement of black carbon. Emissions from this database appear to provide a reasonable estimate of the annual emissions of black carbon to the atmosphere. Biomass burning emissions amount to 5.98 Tg and that from fossil fuel amounts to 7.96 Tg. A local sensitivity analysis has been carried out and shows that black carbon has a lifetime between 6 and 10 days, depending on the transformation rate between hydrophobic and hydrophilic black carbon.
Channel stability in bed load–dominated streams with nonerodible banks: Inferences from experiments in a sinuous flume

[1] Experimental and computational evidence shows that bed state adjustments can accommodate a twofold to fourfold change in sediment supply without otherwise affecting the morphology of a sinuous gravel bed stream channel with nonerodible banks. In contrast, previously published experiments of the same kind but with erodible channel banks suggest that changes in sediment supply are taken up almost exclusively by changes in channel sinuosity and hence the reach-average water surface gradient. It appears that stream channel response to changes in sediment supply is strongly conditioned by the nature of the stream boundary, and that determines which of several potential adjustments are possible.
Negative Corona Discharge from Needle—Plane Electrode: Experiment And Simulation Studies

In electrical equipment, stressed parts with sharp shapes tend to experience corona discharge more quickly. There are two types of corona discharge: positive and negative. A negative corona discharge is generally characterized by highfrequency and trichel pulses. In this study, the characteristics of negative corona discharges were investigated. The effects of voltage on the peak value, average value, and frequency of the Trichel pulses were analyzed. These three parameters were used as the Trichel pulse parameters. The electrode used was a needle plate. A finite element method (FEM)-based simulation was performed. The measurement and simulation results were compared. The results of the analysis showed that the higher the applied voltage, the higher the value of the Trichel pulse parameters. In the simulation results, the peak current values at the voltage level of −4.25 kV and −4.5 kV are 0.102 mA and 0.106 mA, respectively. The peak current values at the voltage level of −4.25 kV and −4.5 kV on the measurement results are 0.088 mA and 0.092 mA, respectively. The root mean square (RMS) error between the measurement and simulation results was 0.0118. This indicates that the comparison between the experimental and simulation results is on agreement.
Detection of changes in hydrologic system memory associated with urbanization in the Great Lakes region

The change of long memory with urbanization in a regional hydrologic system was investigated using both stochastic time series models and a physically based hydrologic model. Based on observed streamflow at five USGS gauge stations in the Great Lakes region, objective fractional autoregressive integrated moving average (FARIMA) model identification and estimation procedures were used for daily streamflow. The recently improved Variable Infiltration Capacity (VIC) model with urban representation was applied to simulate the water and energy response in 16 basins in the region with various degrees of urbanization. The VIC model was driven by different years' land use/cover maps, including a year 1992 base map, and year 2010 and 2030 maps projected by the Land Transformation Model. The ability of the VIC model to capture long memory of observed daily streamflow was evaluated before applying the FARIMA model to all 16 basins. Overall, the northern portion of the domain generally has larger long‐term hydrologic dependence than the southern portion. Simulated streamflow statistics show that the long memory in the hydrologic system has decreased with urbanization. In order to interpret the long memory change with urbanization from a physical point of view, spectral analysis was conducted to examine the spectrum change of soil moisture content with urbanization. The decrease in simulated streamflow long memory relates to the decreased low‐frequency power and amplitude of soil moisture in the deep soil layer. The long‐term response of surface water systems to urbanization should be considered by water resources and urban planners.