Miracle-dz/UniFAR-FTUs huggingface dataset:
Frost flowers as a source of fractionated sea salt aerosol in the polar regions

Frost flowers collected from the surface of new sea ice near the Brunt Ice Shelf, Antarctica, show depletion in sulphate and sodium relative to other sea water ions. This is consistent with loss of mirabilite (Na2SO4) during formation of the brine from which the frost flowers grow. Aerosol generated from frost flowers would have higher sodium:sulphate ratios than aerosol generated from sea water. This would explain low values of non‐sea‐salt sulphate encountered in winter aerosol, and winter layers in ice cores, at coastal Antarctic sites. Calculations confirm that the frost flower source should be significant compared to an open water source for coastal regions.
Subsidence effects on clay barriers

Centrifuge model tests have been performed to study the response of clay barriers subjected to differential deformations. The modes of deformation that have been observed are relevant to those that might occur as the result of differential settlements of waste material leading to deformation of cover liners, or from non-uniform soil strength profiles or the propagation of deep-sited subsidence towards the surface, leading to deformations of the base liner. Plane model liners were constructed both from pure kaolin and from a mixture of sand, silica flour and bentonite. The integrity and performance of these model liners were evaluated on a geotechnical centrifuge at 50 gravities. Physical degradation of the model liners was monitored photographically and their performance as effective hydraulic barriers assessed throughout the deformation process. For all the model liners where no overburden was present, tension cracking of the liner surfaces was observed. These tension cracks were very significant in the .
Satellite Altimeters Measure Tsunami

satellites obtained proﬁ les of sea surface height on transects across the Indian Ocean between two and nine hours after the December 26 Sumatra earthquake. The data are received hours to days af-ter “real time,” too late to be used in detection and warning of tsunamis. We compared the sea level anomaly proﬁ les of December 26 measured along the satellite tracks (Figure 1D-G) with the measurements on previous passes of the same satellites 10 days, 35 days, and 17 days earlier. This allowed us to remove the majority of permanent and slowly varying features of sea level, revealing transient signals. The altimeters also provide wind speed and wave height data, and these allowed us to interpret a sea-level anomaly at 16°S in the Jason-1 proﬁ le (Figure 1D) as being due to a severe storm. The remaining sea-level anomaly signal appears to be associ-ated with the tsunami. The signal of the leading edge two hours after the earth-quake is particularly prominent, with an amplitude of 60 cm and two narrow peaks where the NOAA tsunami model forecast shows two overlapping peaks coalescing into one broad (250 km) crest. Increased sea-surface roughness at spatial scales from 150 to 15 km wave-lengths also appears inside the portion of the ocean excited by the tsunami.The ﬁ rst model simulation results of the Indian Ocean tsunami (Figure 1A-C) were obtained from the “MOST” (Meth-od of Splitting Tsunamis) model (Titov and Synolakis, 1998) and were posted by V.V. Titov on the Internet Tsunami Bul-letin Board less than 12 hours after the earthquake. MOST is part of the tsunami forecasting and warning system under development for the Paciﬁ c Ocean (Titov et al., 2005) that will provide fast real-time estimates of tsunami amplitudes using preset models, real-time seismic data, and, most importantly, deep-ocean tsunami amplitude data from a network of deep-ocean pressure sensors. Other researchers also ran models and posted results. Results of MOST and other mod-el runs have been widely used worldwide by the media for early planning of relief efforts and for post-tsunami ﬁ eld sur-veys. Unlike the Paciﬁ c, the Indian Ocean does not yet have a network of deep-ocean pressure sensors, and so coastal tide gauges provide the only direct mea-surement of Indian Ocean tsunami am-plitudes. The satellite altimeter data we present here are the only measurements of the amplitude of the December 26 tsunami in the deep, open ocean. At the time of the ﬁ rst MOST model simulation, earthquake source mecha-nism models described a rupture con-ﬁ ned to only the southernmost portion of the broad region mapped out by the aftershock pattern. However, it seemed clear that the tsunami should have been generated by displacements distributed along the entire aftershock zone. The initial conditions for the MOST model were set assuming this more spatially distributed source, with initial amplitude guesses based on preliminary estimates of the earthquake magnitude and one coastal tide-gauge measurement from Cocos Island. Because of the lack of
Chemnitz Scientific Computing Preprints

This paper is devoted to the fast solution of interface concentrated finite element equations. The interface concentrated finite element schemes are constructed on the basis of a non-overlapping domain decomposition where a conforming boundary concentrated finite element approximation is used in every subdo-main. Similar to data-sparse boundary element domain decomposition methods the total number of unknowns per subdomain behaves like O((H/h) (d−1)), where H, h, and d denote the usual scaling parameter of the subdomains, the average discretization parameter of the subdomain boundaries, and the spatial dimension, respectively. We propose and analyze primal and dual substructur-ing iterative methods which asymptotically exhibit the same or at least almost the same complexity as the number of unknowns. In particular, the so-called All-Floating Finite Element Tearing and Interconnecting solvers are highly parallel and very robust with respect to large coefficient jumps.
Amplitude versus offset analysis in the presence of dip

Although exploration targets often lie on or near dipping horizons, most studies of seismic amplitude variation with offset have assumed all reflectors to be horizontal. Amplitude-vs.-offset (AVO) analysis need not be restricted to such simple cases. The presence of dip, however, can pose difficulties for AVO analysis. Difficulties arise from: (1) errors in estimating parameters in AVO analysis that depend on reflection angle, (2) mixing of information from different subsurface locations within a common-midpoint gather, (3) the dependence of normal-movement corrections on reflector dip, and (4) interference of reflections by mispositioned events. If these problems are not addressed in processing, the dipping events in AVO analysis can introduce artifacts that lead to erroneous interpretation. In dealing with problems posed by dip, either prestack partial migration or full migration before stack can be used. It is important to ensure that these prestack processes treat amplitude properly. When such care is taken, dip is removed as an issue in performing AVO analysis on data from areas with structural complexity.
Geography matters: patterns of spatial homogamy in the Netherlands

'Cupid may have wings, but apparently they are not adapted for long flights. ' Studies on the spatial dimension of the partner market have found that the number of marriages declines as the distance between potential spouses increases. This paper explores the role of geographical distance in partner choice in the Netherlands. The availability of unique integral micro data from the population register enables us to study spatial homogamy among all new cohabiters. Spatial homogamy is measured by calculating distances between partners before cohabitation. The explorative study shows that geography matters: Dutch persons choose spatially homogamous partners. Spatial homogamy is influenced by demographic factors. With increasing age, spatial homogamy increases. Moreover, those who live with their parents and those who are single parents before cohabitation live significantly shorter to their future partners. Spatial homogamy also exhibits a distinct spatial pattern. However, conditional on population size and geographical location, long distances between partners in peripheral areas become insignificant. Finally, the distance between partners decreases as urbanisation increases. The findings stimulate the discussion on the role of cultural factors in partner choice. Copyright (c) 2008 John Wiley & Sons, Ltd.
Non-cooperative Bargaining Dynamics in Trading Networks

In the study of economic models of trade, it has long been recognized that institutional or physical barriers limit direct trade between some pairs of agents. Network models have been used to study such scenarios since the early 1940s, but only recently did they become objects of active research. This is partly because more and more important network-related phenomena in our economic systems are being observed. Examples of these phenomena include the relationship between network centrality and bargaining/influencing power in social networks; the bull-whip effect in supply chains; and more recently the widespread disruption of financial asset markets. The study of economic networks is becoming increasingly important because it is clear that many classical models that abstract away from patterns of interaction leave certain phenomena unexplained. Non-cooperative bargaining is a game theoretical framework that has been studied extensively by economists, see for example [Osborne and Rubinstein 1990]. Recently, there has been a substantial line of work in both economics and computer science that investigates these models in network settings. Networked bargaining games are interesting not only because in practice many transactions are negotiated (as opposed to being determined by market forces), but also because, conceptually, bargaining is the opposite of the idealized “perfect competition” that is often used in classical models of markets; moreover, when market transactions are constrained by a network, the perfect competition assumption is hard to justify. However, one of the biggest challenges along this line of research is the complexity of networked bargaining games. It has been noted by in [Jackson 2008] that in network games, analyzing “a non-cooperative game that completely models the bargaining process through which ultimate payoffs are determined [. ] is usually intractable. ’’ Having a basic, tractable game theoretical framework and powerful mathematical tools to overcome this complexity is important because this will allow researchers to investigate qualitatively how network influences the economic outcome, and to
Study and Interpretation of the Chemical Characteristics of Natural Water

The chemical composition of natural water is derived from many different sources of solutes, including gases and aerosols from the atmosphere, weathering and erosion of rocks and soil, solution or precipitation reactions occurring below the land surface, and cultural effects resulting from human activities. Broad interrelationships among these processes and their effects can be discerned by application of principles of chemical thermodynamics. Some of the processes of solution or precipitation of minerals can be closely evaluated by means of principles of chemical equilibrium, including the law of mass action and the Nernst equation. Other processes are irreversible and require consideration of reaction mechanisms and rates. The chemical composition of the crustal rocks of the Earth and the composition of the ocean and the atmosphere are significant in evaluating sources of solutes in natural freshwater. The ways in which solutes are taken up or precipitated and the amounts present in solution are influenced by many environmental factors, especially climate, structure and position of rock strata, and biochemical effects associated with life cycles of plants and animals, both microscopic and macroscopic. Taken together and in application with the further influence of the general circulation of all water in the hydrologic cycle, the chemical principles and environmental factors form a basis for the developing science of natural-water chemistry. Fundamental data used in the determination of water quality are obtained by the chemical analysis of water samples in the laboratory or onsite sensing of chemical properties in the field. Sampling is complicated by changes in the composition of moving water and by the effects of particulate suspended material. Some constituents are unstable and require onsite determination or sample preservation. Most of the constituents determined are reported in gravimetric units, usually milligrams per liter or milliequivalents
A preliminary fission track dating survey of Caledonian “newer and last granites” from the Highlands of Scotland

Synopsis The published radiometric age determinations for Scottish Caledonian Newer and Last Granites are reviewed briefly. A short description is given of the theory and techniques of fission track dating. The results of 66 fission track determinations on sphene, zircon and apatite from 17 Newer and Last Granites from the Highlands are presented and their interpretation discussed in relation to previously published ages and the geology of the intrusions. The mean sphene date is 389 ± 8 Myr and the mean zircon date 387 ± 18 Myr; these dates are interpreted as the mean age of initial post-intrusion cooling. Dates from co-existing apatite are substantially lower, showing maxima of ∼ 230 Myr and ∼ 280 Myr. Various interpretations of the apatite data are suggested: the discrepant ages may result from either the slow cooling of the granites at a rate of ∼ 0.8°C/Myr, or from the partial or complete resetting of the dates by subsequent thermal events, or from a combination of slow cooling and resetting.
Iodine to calcium ratios in marine carbonate as a paleo-redox proxy during oceanic anoxic events

Periods of globally distributed extreme oxygen depletion, so-called oceanic anoxic events (OAEs), have been recognized in the Mesozoic geological record and appear to be characteristic of episodes of extreme warmth. Here we explore the application of iodine/calcium ratios (I/Ca) in marine carbonate as a new geochemical proxy to constrain seawater redox change, and provide additional insights into the response of ocean chemistry to ancient climatic warming. Iodine has long been known as a redox-sensitive and biophilic element, mainly present as iodate and iodide in seawater, iodate converting to iodide under anoxic conditions. Laboratory experiments growing calcite crystals from solutions spiked with iodate show that this is the ionic species incorporated into the carbonate structure, likely substituting for the CO 3 2− ion. A fall in the I/Ca ratio measured in carbonates formed in shallow water by marine calcifiers during the early Toarcian and Cenomanian-Turonian OAEs is interpreted both as a response to a decrease in the iodate/iodide ratio in ocean waters and the drawdown of the global iodine inventory under conditions of accelerated organic-matter burial. The results suggest that I/Ca ratios in carbonates may be used to monitor seawater oxidation levels throughout Earth history.
Microphysics of clouds and rain over the Western Ghat

In an attempt to unravel the interactions between cloud microphysics and dynamics that make shallow clouds precipitate heavily in this region, some unique observations of rain and cloud microphysical parameters are presented here from two stations, Pune and Mahabaleshwar, one each on the lee and windward sides, respectively, of the Western Ghat (WG) mountains in peninsular India. To elucidate rain microphysics, we used the raindrop size distribution (DSD) by fitting three parameter Gamma functions to the observed raindrop spectra. Over Pune, during stratiform rain with bright band (BB) at 0°C isotherm; concave upward DSD shapes are observed below the BB which becomes concave downward at lower altitudes. It is due to breakup process of large raindrops which increases drop concentration at midsizes suggesting coalescence, collision, and breakup processes. Both slope and intercept parameters of Gamma DSD decrease during no BB condition as altitudes decrease, signifying collision and coalescence processes. Over Mahabaleshwar, bimodal and monomodal DSD are observed during light and heavy rainfall, respectively. With shallow storm heights, small raindrops mainly contribute to both types of rainfall. The DSDs are parameterized, and their radar reflectivity factor‐rainfall intensity relationships are evaluated suggesting the dominance of collision‐coalescence processes. Aircraft measurements of orographic clouds over the WG suggest interaction of cloud mass with the ambient updraft speed. The orographically forced updrafts foster rapid condensational growth of cloud droplets triggering coalescence process within few hundred meters of cloud depth. Hence, these clouds are dynamically forced to produce precipitation over the WG.
Effect of point density and interpolation of LiDAR-derived high-resolution DEMs on landscape scarp identification

Recognition of geomorphic features, such as landslide scarps, is the first key step for landslide risk assessment and mitigation. Geomorphic features can be identified from high-resolution digital elevation model (DEM). Light Detection and Ranging (LiDAR) is a useful tool to collect high-density point elevation data from ground surfaces. LiDAR ground points are used to generate high-resolution DEMs. However, LiDAR sample sizes and interpolation methods are critical parameters for DEM estimation under various land cover types. To discuss the effect of the parameters, this study used a series of cases to estimate the DEMs and identify the landslide scarps, especially potential landslide scarps hidden in the forest. Results show that LiDAR sample size affects the visual identification rate of the landslide scarps. The point density of LiDAR data controls the level of detail that can be resolved in the LiDAR-derived DEM. Given low-density LiDAR ground points, the DEM accuracy is the worst, especially in dense forest. Particularly in sparse samples, the identification rate of the landslide scarp is sensitive to the interpolation method. In sparse samples, landslide scarp identification based on Kriging-estimated DEM showed the best results among the three interpolation methods. Hence, this study provides information for the assessment of the effects of sample sizes under land cover for further geomorphic monitoring, assessment and management.
Effects of flooding regime upon the decomposition of Eichhornia azurea (Sw.) Kunth measured on a tropical, flow‐regulated floodplain (Paraná River, Brazil)

Decomposition of macrophytes is an important process in river‐floodplain systems, especially in the Upper Paraná River floodplain, given that this ecosystem receives high inputs of detritus from this vegetation. Release of nutrients by decomposition is essential in this floodplain because it is located downstream from a reservoir chain where nutrients are being trapped. Water level fluctuations are considered one of the most important aspects that affect macrophyte decomposition. Anthropogenic alterations, such as the control of flooding regimes, observed in this floodplain, could change the dynamic of this process. To evaluate the influence of the hydrological cycle upon the decomposition of Eichhornia azurea (an aquatic macrophyte that has high biomass values in this ecosystem), litter bags with senescent leaves and petioles of this plant were submitted to four different flooding treatments, which differed in time of flooding and exposure to dry conditions. The decomposition rates and the detritus chemical composition (nitrogen and phosphorus concentrations) were measured over 113 days. There were significant effects of the flooding treatments and time upon all parameters. The materials that decomposed with flood conditions showed the greatest decomposition rates. The quality of the detritus seems to be highly linked with the flooding regime, showing highest releases of phosphorus in the submerged treatments. It was shown that floods, even the short duration ones, increase the decomposition velocity and the nutrient cycling relative to dry conditions. Thus, investigations that assess the nutrient budgets on the Upper Paraná River floodplain and the role of nutrients in its productivity should consider the detritus compartment and the effects of flood regimes upon its dynamics. Copyright © 2006 John Wiley & Sons, Ltd.
Volcanic glass and its suitability to recover the ancient geomagnetic field strength

Abstract The determination of the past ancient magnetic field intensity is typically very difficult and error prone. Fresh volcanic glass has been suggested to be an ideal material for obtaining direction and strength of the magnetic field. Domain state bias is generally absent, thermal alteration is normally negligible and, as demonstrated in this study, cooling-rate differences can be corrected for. Major issues remaining include alteration and the origin of the remanence: that is, whether it is a true thermo-, a thermochemical or, for altered samples, a chemical remanence. Hydration, devitrification and perlitization lead to incorrect estimates of the palaeointensity, which are very difficult to recognize as the palaeointensity analysis does not easily expose these biasing effects and points towards ‘reliable’ results. Particular care on sampling and/or volatile measurements are necessary to overcome these drawbacks.
Determination of ocean primary productivity using support vector machines

A major task of ocean colour observations is to determine the distribution of phytoplankton primary production. At present, the global coverage of the sea surface chlorophyll concentration, sea surface temperature, photosynthetically available radiation (PAR) can nominally be achieved every 1 to 2 days with standard algorithms from satellite data. From these standard products, a variety of bio‐optical algorithms has been developed to estimate ocean primary productivity. In this communication, we have investigated the possibility of using a novel universal approximator‐support vector machine (SVM) as the nonlinear transfer function between ocean primary productivity and the information that can be retrieved from satellite data, including chlorophyll concentration, PAR, maximum carbon fixation rate and day length, which is the same as the vertically generalized production model (VPGM). The VGPM dataset was used to evaluate the proposed approach. The primary production algorithm round robin 2 (PPARR2) dataset was used to further compare the precision between the VGPM and the SVM model. The results suggest that the SVM model is more accurate than the VGPM. Using the SVM model to calculate the global ocean primary productivity, the result is 45.5 Pg C yr−1, which is a little higher than the VGPM result.