Miracle-dz/UniFAR-FTUs huggingface dataset:
Thermospheric response observed over Fritz Peak, Colorado, during two large geomagnetic storms near Solar Cycle Maximum

Nighttime thermospheric winds and temperatures have been measured over Fritz Peak Observatory, Colorado (39.9°N, 105.5°W), with a high resolution Fabry-Perot spectrometer. The winds and temperatures are obtained from the Doppler shifts and line profiles of the (O I) 15,867K (630 nm) line emission. Measurements made during two large geomagnetic storm periods near solar cycle maximum reveal a thermospheric response to the heat and momentum sources associated with these storms that is more complex than the ones measured near solar cycle minimum. In the earlier measurements made during solar cycle minimum, the winds to the north of Fritz Peak Observatory had an enhanced equatorward component and the winds to the south were also equatorward, usually with smaller velocities. The winds measured to the east and west of the observatory both had an enhanced westward wind component. For the two large storms near the present solar cycle maximum period converging winds are observed in each of the cardinal directions from Fritz Peak Observatory. These converging winds with speeds of hundreds of meters per second last for several hours. The measured neutral gas temperature in each of the directions also increases several hundred degrees Kelvin. Numerical experiments done with the NCAR thermospheric general circulation model (TGCM) suggest that the winds to the east and north of the station are driven by high-latitude heating and enhanced westward ion drag associated with magnetospheric convection. The cause of the enhanced poleward and eastward winds measured to the south and west of Fritz Peak Observatory, respectively, is not known. During geomagnetic quiet conditions the circulation is typically from the southwest toward the northeast in the evening hours. We speculate that the enhanced flow to the south and west of Fritz Peak Observatory may be due to either (1) a hemispheric difference in the thermospheric energy input rate, (2) equatorial heating by neutral hydrogen precipitation, or (3) an increased midnight equatorial temperature bulge or some combination of these sources. Since the measurements indicate that the winds in the 630-nm airglow layer converge from all directions at the observatory, we speculate that Fritz Peak is at the boundary of two circulation patterns during part of the storm.
Estimating the Relative Uncertainties Sourced from GCMs and Hydrological Models in Modeling Climate Change Impact on Runoff

AbstractThis paper assesses the relative uncertainties from GCMs and from hydrological models in modeling climate change impact on runoff across southeast Australia. Five lumped conceptual daily rainfall–runoff models are used to model runoff using historical daily climate series and using future climate series obtained by empirically scaling the historical climate series informed by simulations from 15 GCMs. The majority of the GCMs project a drier future for this region, particularly in the southern parts, and this is amplified as a bigger reduction in the runoff. The results indicate that the uncertainty sourced from the GCMs is much larger than the uncertainty in the rainfall–runoff models. The variability in the climate change impact on runoff results for one rainfall–runoff model informed by 15 GCMs (an about 28%–35% difference between the minimum and maximum results for mean annual, mean seasonal, and high runoff) is considerably larger than the variability in the results between the five rainfall–.
Planktonic foraminiferal Cd/Ca: Paleonutrients or paleotemperature?

Records of Cd/Ca in planktonic foraminiferal calcite of Globigerinoides bulloides in cores from the Subantarctic region of the Southern Ocean show large glacial-interglacial variations with lower Cd/Ca (by 0.06–0.10 µmol mol−1) at glacial times. Interpretation of these records in terms of lower dissolved phosphate and inferred higher glacial nutrient utilization has significant implications for glacial atmospheric carbon dioxide (pCO2) draw-down. However, box core-top data for G. bulloides in the North Atlantic suggest that the incorporation of Cd into planktonic foraminifera relative to seawater (DCd) is temperature sensitive (DCd=0.637 exp 0.15T). When the Subantarctic planktonic Cd/Ca records are corrected for this temperature dependence, they show little or no glacial-interglacial diferences. If, as seems likely, this observation can be interpreted to indicate a minimal change (< 0.5 µmol kg−1) in surface water phosphate concentrations, then the explanation for lowered glacial pCO2 must be looked for elsewhere.
Policies drain the North China Plain: Agricultural policy and groundwater depletion in Luancheng County, 1949-2000

The report examines the relationships between agricultural policies in the North China Plain, the approaches to water management that evolved from them, the quantity of water that was actually used, and the consequent groundwater depletion beneath Luancheng County, Hebei Province, from 1949 to 2000. To systematically address these relationships, we use a comprehensive water-balance approach. Our results indicate that a single, longstanding policy-that of using groundwater to meet the crop-water requirements not supplied by precipitation-is responsible for the steady rate of groundwater decline.
Minesite groundwater contamination mapping

A number of electromagnetic and electrical methods have been applied jointly to map groundwater contamination near minesite landforms. The main methods being investigated are transient electromagnetic (TEM) and direct current (DC) resistivity soundings, DC profiling, self potential (SP), and induced polarisation (IP) measurements, combined with any existing hydrogeological and hydrogeochemical data. At the tailings dam of the disused Brukunga pyrite mine in South Australia, reaction of groundwater with the tailings causes the formation and discharge of sulphuric acid. Geophysical methods have been investigated to determine whether they can be used to characterise variations in depth to watertable and map preferred groundwater flow paths through the tailings dam. The results of the geophysical surveys show that it is difficult to determine any preferred channels of groundwater flow from SP profiling data alone, but TEM and DC sounding measurements have enabled accurate determination of watertable levels and aquifer resistivity. The shallowest and most resistive part of the aquifer occurs in the southeast of the site, and we deduce that a possible source of fresh groundwater entering the site occurs here. It has been recommended that efforts to reduce acid formation in the tailings dam should concentrate on reducing this inflow of groundwater.
Effect of periodate and pyrophosphate on the seasonal changes in aggregate stabilization

Aggregates taken from sequential samplings of a range of red-brown earths showed a definite seasonal trend in relative stability. Maximum stability of the aggregates occurred in the summer, followed by a gradual decline during the autumn and early winter and an increase in the spring and early summer. In all phases of the crop-pasture rotation on all the red-brown earths, this trend was minimized by a combination of chemical treatments, designed to oxidize polysaccharides and polyuronides and to break the organic matter-polyvalent cation-clay bridge. The residual aggregate stability after the combined chemical treatment increased with the proportion of pasture phase in the rotation. Individually, the chemical treatments reduced the aggregate stability by a constant amount throughout all the seasons. The aggregate stabilizing mechanisms broken by the individual treatments make a constant contribution to stability throughout the year. This contribution increases with increasing cultivation in the rotation. In contrast, the aggregates taken from the solonized brown soil were stabilized by calcium carbonate. No seasonal trend or rotational effect was evident in these aggregates.
Examples of Mechanisms for Negative Cloud Feedback of Stratocumulus and Stratus in Cloud Parameterizations

Mechanisms of cloud feedback for marine boundary layer clouds in GCMs (General Circulation Models) to the sea surface temperature increase, which can depend on parameterization, were investigated using single column model version of a GCM with two different low cloud schemes. Both schemes showed negative cloud feedbacks and they were attributed to the increase of the liquid water path (LWP) with the future climate forcing for stratocumulus and stratus. The mechanisms of the LWP increase in the two schemes were inves- tigated respectively through simple numerical experiments. The experimental results imply that in the first scheme, the increase of saturation specific humidity due to the temperature increase in the future climate forcing contributes to the negative cloud feedback through the parameterization determining in-cloud cloud water content (CWC). The results also imply that the increase of latent heat flux in the future climate contributes to increased LWP and hence negative cloud feedback in the other scheme.
Planforms of self‐consistently generated plates in 3D spherical geometry

In the past decade, several studies have documented the effectiveness of plastic yielding in causing a basic approximation of plate tectonic behavior in mantle convection models with strongly temperature dependent viscosity, strong enough to form a rigid lid in the absence of yielding. The vast majority of such research to date has been in either two‐dimensional, or three‐dimensional cartesian geometry. In the present study, mantle convection calculations are performed to investigate the planform of self‐consistent tectonic plates in three‐dimensional spherical geometry. The results are compared to those of similar calculations where a three dimensional cartesian geometry is used. We found that when yield stress of the lithosphere is low (∼20 MPa) a “great circle”‐subduction zone forms. At low‐intermediate yield stresses (∼100 MPa) plates, spreading centers and subduction zones formed and were destroyed over time. At high‐intermediate yield stresses (∼200 MPa) two plates form, separated by a great circle boundary that is a spreading centre on one side and a subduction zone on the other side. At high yield stresses (∼400 MPa) a rigid lid was observed. The great circle subduction zone and the rigid lid are stable over time while at intermediate yield stresses some episodic behavior is observed. The spherical cases showed a higher, more Earth‐like, toroidal‐poloidal ratio of the surface velocity field than the cartesian cases.
Evaluating the quality of hydraulic conductivity estimates from piezometer slug tests in peat

Although widely used in wetland hydrological studies, hydraulic conductivity (K) estimates from piezometer slug tests are often of questionable validity. Frequently, this is because insufficient attention is paid to the details of the test procedure. Further, in a potentially heterogeneous and anisotropic medium such as peat, the use of slug tests is prone to error. In this paper we address some of the methodological issues surrounding piezometer slug tests in peat. We compare slug test data with laboratory determinations of vertical and horizontal K obtained using a new method. Piezometers were installed at three depths in a floodplain fen peat in Norfolk, UK. Slug tests were initiated by both slug insertion and slug withdrawal, and repeat tests were conducted to examine the robustness of our K estimates. Most of the tests displayed departures from the log‐linear model of Hvorslev, the form of departure being consistent with compressible soil behaviour. The results suggest that insertion tests gave similar results to those initiated by withdrawal. Repeat testing showed that withdrawal data, in particular, gave highly reproducible normalized responses that were independent of the initial head. Values for K estimated using the slug tests were in the range 1 × 10−4 to 1·6 × 10−3 cm s−1, which is towards the upper end of the range reported for peats generally. Laboratory tests yielded similar values of K to those obtained from the slug tests. Although the laboratory tests showed that the peat was anisotropic, the K values generated by slug testing proved relatively good estimates of both vertical and horizontal K. Copyright © 2005 John Wiley & Sons, Ltd.
Myths and realities: the performance impact of garbage collection

This paper explores and quantifies garbage collection behavior for three whole heap collectors and generational counterparts: copying semi-space, mark-sweep, and reference counting, the canonical algorithms from which essentially all other collection algorithms are derived. Efficient implementations in MMTk, a Java memory management toolkit, in IBM's Jikes RVM share all common mechanisms to provide a clean experimental platform. Instrumentation separates collector and program behavior, and performance counters measure timing and memory behavior on three architectures.Our experimental design reveals key algorithmic features and how they match program characteristics to explain the direct and indirect costs of garbage collection as a function of heap size on the SPEC JVM benchmarks. For example, we find that the contiguous allocation of copying collectors attains significant locality benefits over free-list allocators. The reduced collection costs of the generational algorithms together with the locality benefit of contiguous allocation motivates a copying nursery for newly allocated objects. These benefits dominate the overheads of generational collectors compared with non-generational and no collection, disputing the myth that "no garbage collection is good garbage collection. " Performance is less sensitive to the mature space collection algorithm in our benchmarks. However the locality and pointer mutation characteristics for a given program occasionally prefer copying or mark-sweep. This study is unique in its breadth of garbage collection algorithms and its depth of analysis.
COMPARISON OF FRICTIONAL MATERIAL MODELS WITH RESPECT TO SHEAR BAND INITIATION

The existing elasto-plastic models of geomaterials have been developed on the basis of experiments in which uniform straining was attempted. The shear bands observed in experiments have been described directly without direct relation to the elasto-plastic models. However, shear band initiation can be considered as an instability of plastic flow; consequently the material behaviour under uniform deformation and the occurrence of a shear band can be considered as coupled phenomena. In this Paper the coupling relations are elaborated and applied in the calculation of shear band initiation for a range of popular constitutive models of materials like drained clay, sand, concrete and rock. It is found that amongst the popular elasto-plastic models large variations in the predicted slope of the shear band and the predicted instant of initiation occur. Les modeles elasto-plastiques des sols existants ont ete developpes sur la base d'essais dans lesquels une deformation uniforme est imposee. La formation des surfa.
When microgenetics meet enactivism: knowledge transformation among apprentice psychotherapists

Microgenetic learning analyses have been developed in a cognitive perspective, they allow retracing knowledge transformation; but they necessitate an important body of prior research for identifying “knowledge-in-piece” elements. A microgenetic approach in a phenomenal / enactivist perspective could offer other possibilities. We crafted such an approach in the context of a vocational training program for psychotherapist. Our method meets the three criterions defining a microgenetic approach: focusing on a period of rapidly changing competence / high density of observation / intensive data analysis. For five monthly seminars, we conducted in depth interviews during which three participants explicitated their experience during the different moments of each seminar. These data led us to identify units of activity and significant “distinctions” for describing the transformations of knowledge for these participants. The training program led participants to experience a multiplicity of different distinctions; a lot were about participants themselves. However, these distinctions were structured by a limited number of personal themes related to each participant’s course of life. At this point of our research, we wonder if these findings come from the domain and the pedagogy of the training program we study, or from the framework we endorse. The study of knowledge transformation in the second part of the training program, during which structuring concept will be taught, could give us an answer.
Evaluating model‐simulated variability in temperature extremes using modified percentile indices

Percentile indices monitoring the frequency of moderate temperature extremes are widely used to assess changes in present and future temperature extremes because of their straightforward interpretation. While observed trends in such indices can be, and have been, compared with model‐simulated trends, their definition relative to each model's own climatology inhibits their use for the evaluation of model‐simulated temperature variability. This is unfortunate, as in many parts of the world, indices from observations remain the only source of publicly available information about extreme temperature variability. We approach this problem by introducing a novel adjustment to the standard method for deriving indices from climate models. This involves the removal of the bias in the mean annual cycle of the models and the use of percentile thresholds from a reference data set. We illustrate the technique by comparing daily minimum (TN) and maximum (TX) temperatures from the fifth phase of Coupled Model Intercomparison Project (CMIP5) historical simulations with those from an observation‐based data set and from the National Centers for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) and the European Centre for Medium‐Range Weather Forecasts (ERA‐40) reanalyses. Biases in the annual cycle also translate into biases in the representation of the percentile indices in the models and reanalyses. Generally, percentile indices based on daily TX are well represented by the models and reanalyses compared to the observations. For percentile indices based on daily minimum temperature, however, large discrepancies occur particularly between the reanalyses.
Isostatic response to loading of the crust in Canada

A smoothed free air anomaly map of Canada indicates that the central part of the region occupied by the Laurentide Ice Sheet is over-compensated. Due to the close association of the free air gravity, the apparent crustal warping, the time of deglaciation, and the congruence of the gravity anomalies and the Wisconsin Glaciation, it is concluded that the over-compensation is due to incomplete recovery of the lithosphere from the displacement caused by the Pleistocene ice loads. The amplitude of the anomalies, about –50 milligals, suggests that a substantial amount of uplift has yet to occur and that the relaxation time of crustal warping is of the order of 10 000 to 20 000 y.The profile of the ground surface at the edge of a continental ice sheet on an elastic lithosphere is assessed using a value of the flexural parameter of the lithosphere calculated from gravity and deformation studies in the Interior Plains. The conclusions are: (a) a purely elastic forebulge is not likely to reach an amplitude of more .
On-board hyperspectral compression and analysis system for the NEMO satellite

The primary mission of the Naval EarthMap Observer (NEMO) is to demonstrate the importance of hyperspectral imagery in characterizing the littoral battlespace environment and littoral model development. NEMO will demonstrate real time on-board processing and compression of hyperspectral data with real-time tactical downlink of ocean and surveillance products directly from the spacecraft to the field. The NRL's Optical Real-time Adaptive Spectral Identification System (ORASIS) will be deployed on a 3.8 Gflop multiprocessing computer, the Imagery On-Board Processor (IOBP), for automated data analysis, feature extraction and compression. NEMO's wide area coverage (106 km2 imaged per day), as well as power and cost constraints require data compression between 10:1 and 20:1. The NEMO Sensor Imaging Payload (SIP) consists of two primary sensors: first, the Coastal Ocean Imaging Spectrograph (COIS) is a hyperspectral imager which records 60 spectral bands in the VNIR (400 to 1000 nm) and 150 bands in the SWIR (1000 to 2500 nm), with a GSD of either 30 or 60 meters; and second, the 5 m GSD Panchromatic Imaging Camera (PIC). This paper describes the design and implementation of the data processing hardware and software for the NEMO satellite.
Vertical structure of the troposphere as revealed by radioactive tracer studies

The fallout of several radioisotopes of diverse origins (i.e., cosmogenic isotopes 7Be and 32P, radongenic 210Pb, 210Bi, and 214Bi, and bomb-produced 22Na) has been measured in precipitation at several stations on the Indian subcontinent. The average residence time of cosmogenic (and bomb-produced) isotopes in the troposphere is found to be longer than that of the radongenic isotopes. This behavior can be explained only if the rate of removal of aerosols, in general, decreases with altitude. Such a structure of the troposphere is probably seasonally variable. The concentrations of 210Pb, 7Be, and 32P have been measured in the air in the troposphere. The results, combined with similar data, suggest that the concentrations in the troposphere at 0–15°N latitude are unusually small. This effect seems to be a direct result of good vertical mixing and efficient washout in this belt.
Ion microprobe U—Pb zircon and baddeleyite ages for the Great Dyke and its satellite dykes, Zimbabwe

The Great Dyke and its two main satellites, the Umvimeela and East Dykes, trend in a north—northeast direction across Archaean basement rocks of the Zimbabwe Craton. SHRIMP analysis of baddeleyite from all three intrusions yields statistically identical results and confirms their essentially synchronous emplacement at 2574 ±2 Ma. SHRIMP U—Pb data for zircons from the Great Dyke are variably discordant and yield an upper intercept age of 2581 ±11 Ma. Dispersion ofthe data, however, implies that the zircons have lost variable amounts ofradiogenic Pb between about 1200 and 700 Ma, possibly during more than one event. Pb loss at about 700 Ma may be related to theonset of Pan-African tectonism. Pb loss at about 1100 Ma is consistent with chemical alteration during the craton-wide Umkondo igneous event, as demonstrated by previous palaeomagnetic data for the UmvimeelaDyke. Because the effects of multiple Pb loss events cannotbe quantified, a more reliable age estimate for zircon crystallization is 2571 ±9 Ma, based on the mean 207Pb*/206Pb* of the five most concordant analyses. Although an age of 2587 ±8 Ma has been reported for crystallization of the Great Dyke, recalculation of the previous U—Pb rutile and zircon data indicates that an age of 2574 Mais more appropriate.