Miracle-dz/UniFAR-FTUs huggingface dataset:
Macro‐scale exhaustion of surface phosphate by dinitrogen fixation in the western North Pacific

In the subtropical oceans, nutrient concentrations are frequently below the detection limits of standard analytical methods. We applied a highly sensitive method to the surface water of the western and central Pacific between 42°N and 40°S and between 141°E and 158°W except in the equatorial zone, and detected overall depletion of nitrate + nitrite and an excess of SRP. However, a remarkable exception was found: an almost complete exhaustion of SRP (<10 nM) existed at a horizontal scale of >2000 km in the western subtropical North Pacific in both summer and winter. The SRP exhaustion was a consequence of an elevated dinitrogen fixation, which occurred in areas with high dust deposition from the Asian continent that likely enhanced SRP consumption. A coupling among nutrient dynamics, dinitrogen fixation and dust deposition produces the extremely low P availability spanning a large area, which appears to be unique to the western North Pacific.
Distinguishing the effects of climate on discharge in a tropical river highly impacted by large dams

Abstract The hydrological regime of a river is defined by variables or representative curves that in turn have characteristics related to fluctuations in flow rates resulting from climate variability. Distinguishing between the causes of streamflow variations, i.e. those resulting from human intervention in the watershed and those due to climate variability, is not trivial. To discriminate the alterations resulting from climate variation from those due to regulation by dams, a reference hydrological regime was established using the classification of events based on mean annual streamflow anomalies and inferred climatic conditions. The applicability of this approach was demonstrated by analysis of the streamflow duration curves. An assessment of the hydrological regime in the lower reaches of the São Francisco River, Brazil, after the implementation of hydropower plants showed that the operation of the dams has been responsible for 59% of the hydrological changes, while the climate (in driest conditions) has contributed to 41% of the total changes. Editor Z.W. Kundzewicz Citation Genz, F. and Luz, L.D. , 2012. Distinguishing the effects of climate on discharge in a tropical river highly impacted by large dams. Hydrological Sciences Journal, 57 (5), 1020–1034.
Why are surface equatorial ENSO winds anomalously westerly under anomalous large-scale convection?

Abstract Previous work has shown that the near-surface tropospheric response to anomalous heating can be described in terms of damped equatorial Rossby waves and a damped equatorial Kelvin wave. The zonal and meridional extent of the dominant ENSO heating/cooling region is such that the westward decaying Rossby waves dominate the response. Consequently, eastward of the forcing region the flow is small. Zonal convergence caused by the heating and small zonal flow to the cast together imply that winds must be anomalously westerly in the beating region.
Improving surface boundary conditions with focus on coupling snow densification and meltwater retention in large-scale ice-sheet models of Greenland

Abstract Snowpack changes during the melt season are often not incorporated in modelling studies of the surface mass balance of the Greenland ice sheet. Densification of snow accelerates when meltwater is present, due to percolation and subsequent refreezing, and needs to be incorporated in ice-sheet models for ablation calculations. In this study, simple parameterizations to calculate surface melt, snow densification and meltwater retention are included as surface boundary conditions in a large-scale ice-sheet model of Greenland. Coupling the snow densification and meltwater-retention processes achieves a separation of volume and mass changes of the surface layer, in order to determine the surface melt contribution to runoff. Experiments for present-day conditions show that snow depth at the onset of melt, mean annual near-surface air temperature and the mean density of the annual snow layer are key factors controlling the quantity and spatial distribution of meltwater runoff above the equilibrium line on the Greenland ice sheet.
Estimation of LNAPL saturation in fine sand using time-domain reflectometry / Estimation de la saturation en LPNAL dans du sable fin grâce à la réflectométrie en domaine temporel

Abstract Abstract Recently, substantial progress has been made in detection and observation of non-aqueous phase liquids (NAPLs) in the subsurface using different experimental techniques. However, there is still a lack of appropriate direct methods to measure the saturation of NAPL (θNAPL). This paper provides a guide for estimating θNAPL and water content (θ w ) in unsaturated and saturated sand based on direct measurements of soil dielectric constant (Ka ) and electrical conductivity (σ a ) using time domain reflectometry (TDR). The results show that the previously used dielectric mixing model fails to predict θNAPL in the case of a four-phase system. A new methodology is suggested and exemplified by showing that the measured Ka gives accurate estimation of θNAPL for a three-phase system while in a four-phase system, both θ a and Ka need to be measured. The results show that using the suggested methodology, accurate predictions of θ w (R 2 = 0.9998) and θNAPL lower than 0.20 m3 m-3 (average R 2 = 0.9756) are possible.
Nondestructive Soil Bulk Density Measurements by X-ray Attenuation

Nondestructive density measurement of soil samples in the laboratory has a number of important applications. It can be used to monitor the progress of soil settlement through water and subsequent consolidation to a final equilibrium state, with or without an additional applied load. It can provide information on moisture content distribution in laboratory samples, in both static and changing conditions, and on soil structure in undisturbed cores. This paper describes a nondestructive technique for density measurement that can achieve accuracies in measured soil density of the order of ± 0.005 g/cm3 and a spatial resolution of ± 1 mm. The technique uses an X-ray system with a scintillation detector and counter assembly to record the radiation transmitted through the soil sample. This is converted to a density value by empirical calibration. The principles of the method are described with consideration given to the variables of the measuring system, the beam collimation, and the sample geometry. The method is shown to be reliable and versatile.
Inspirational or Self-Deflating : The Role of Self-Efficacy in Elite Role Model Effectiveness

This research examines the role of self-efficacy in women’s responses to elite leadership role models. Previous research on role models has been equivocal, demonstrating that the impact of social comparisons on the self is multifaceted. Using an experimental methodology, 102 female participants were presented with role models (elite, non-elite, control) before serving as the leader of an ostensible 3-person group. Findings revealed that women with low, as opposed to high, levels of leadership self-efficacy were less inspired by the highly successful role models and showed deflating contrast effects as demonstrated in their diminished identification with leadership, leadership aspirations, and leadership performance. Moreover, the performance effects were mediated by participants’ identification with leadership. This research has identified an important self-regulatory variable that influences whether people engage in assimilative or contrastive processes when making strategic comparisons and it identifies the important role of self-perception outcomes on behavioral responses to role models.
Patent Foramen Ovale Closure and Medical Treatments for Secondary Stroke Prevention: A Systematic Review of Observational and Randomized Evidence

Background and Purpose— Patients discovered to have a patent foramen ovale in the setting of a cryptogenic stroke may be treated with percutaneous closure, antiplatelet therapy, or anticoagulants. A recent randomized trial (CLOSURE I) did not detect any benefit of closure over medical treatment alone; the optimal medical therapy is also unknown. We synthesized the available evidence on secondary stroke prevention in patients with patent foramen ovale and cryptogenic stroke. Methods— A MEDLINE search was performed for finding longitudinal studies investigating medical treatment or closure, meta-analysis of incidence rates (IR), and IR ratios of recurrent cerebrovascular events. Results— Fifty-two single-arm studies and 7 comparative nonrandomized studies and the CLOSURE I trial were reviewed. The summary IR of recurrent stroke was 0.36 events (95% confidence interval [CI], 0.24–0.56) per 100 person-years with closure versus 2.53 events (95% CI, 1.91–3.35) per 100 person-years with medical therapy. In comparative observational studies, closure was superior to medical therapy (IR ratio=0.19; 95% CI, 0.07–0.54). The IR for the closure arm of the CLOSURE I trial was higher than the summary estimate from observational studies; there was no significant benefit of closure over medical treatment (P=0.002 comparing efficacy estimates between observational studies and the trial). Observational and randomized data (9 studies) comparing medical therapies were consistent and suggested that anticoagulants are superior to antiplatelets for preventing stroke recurrence (IR ratio=0.42; 95% CI, 0.18–0.98). Conclusions— Although further randomized trial data are needed to precisely determine the effects of closure on stroke recurrence, the results of CLOSURE I challenge the credibility of a substantial body of observational evidence strongly favoring mechanical closure over medical therapy.
N ° 2008-49 Optimal linear taxation under endogenous longevity

This paper studies the optimal linear tax-transfer policy in an economy where agents di¤er in productivity and in genetic background, and where longevity depends on health spending and genes. It is shown that, if agents internalize imperfectly the impact of genes and health spending on longevity, the utilitarian social optimum can be decentralized with type-speci c redistributive lump sum transfers and Pigouvian taxes correcting for agentss myopia (leading to undersaving and underinvestment in health), and for their incapacity to perceive the e¤ect of health spending on the resource constraint of the economy (causing overinvestment in health). The second-best problem is also examined under linear taxation instruments. Our main result is that it may be optimal to tax health spending, in particular under a complementarity of genes and health spending in the production of longevity.
Remanent magnetization of some Upper Cretaceous granitic plutons in the Sierra Nevada, California

Extensive sampling of the granitic plutons in Yosemite National Park, California, led to the retention of nine sites distributed in three plutons (Gateway, Sentinal, Half Dome) ranging in age (K-Ar) from about 89 to 79 million years (early Upper Cretaceous). Many specimens are unstable; they carry, in addition to their thermal remanence, a ‘random’ component of unknown origin. Mean directions for large numbers of specimens seem, however, to be significant. The mean pole for that time falls at 73.5°N, 174°E, in agreement with previous results. Virtual poles for the several sites are scattered with an angular deflection factor δ = 10.2°; they appear to show a clockwise (east to west) rotation of the geomagnetic pole about the mean rotational pole with a period of 105 to 106 years. There are some indications that the secular variation is not entirely smoothed out in a time of the order of 105 years.
The oceanography of winter leads

Leads in pack ice have long been considered important to the thermodynamics of the polar regions. A winter lead affects the ocean around it because it is a density source. As the surface freezes, salt is rejected and forms more dense water which sinks under the lead. This sets up a circulation with freshwater flowing in from the sides near the surface and dense water flowing away from the lead at the base of the mixed layer. If the mixed layer is fully turbulent, this pattern may not occur; rather, the salt rejected at the surface may simply mix into the surface boundary layer. In either event the instability produced at the surface of leads is the primary source of unstable buoyancy flux and, as such, exerts a strong influence on the mixed layer. Here as many as possible of the disparate and almost anecdotal observations of lead oceanography are assembled and combined with theoretical arguments to predict the form and scale of oceanographic disturbances caused by winter leads. The experimental data suggest the velocity disturbances associated with lead convection are about 1–5 cm s−1. These appear as jets near the surface and the base of the mixed layer when ice velocities across the lead are less than about 5 cm s−1. The salinity disturbances are about 0.01 to 0.05 psu. Scaling arguments suggest that the geostrophic currents set up by the lead density disturbances are also of the order of 1–5 cm s−1. The disturbances are most obvious when freezing is rapid and ice velocity is low because the salinity and velocity disturbances in the upper ocean are not smeared out by turbulence. In this vein, lead convection may be characterized at one extreme as free convection in which the density disturbance forces the circulation. At the other extreme, lead convection may be characterized as forced convection in which the density disturbance is mixed rapidly by boundary layer turbulence. The lead number Lo, which is the ratio of the pressure term to the turbulence term in the momentum equation, and the turbulent lead number Lot, which is the ratio of buoyant production to shear production in the turbulent kinetic energy equation, define the boundary between the free and forced regimes. For Lo and Lot less than one, both the large-scale circulation and the turbulence are forced by surface stress. For Lo and Lot greater than one, both the large-scale circulation and the turbulence are forced by the buoyancy flux. The magnitudes of velocity and salinity disturbances from a model developed elsewhere, suitable to free convection, agree with what few observations we have. The results of a forced convection model, developed here, suggest salinity disturbances of the order of 0.01–0.02 practical salinity units, with the maximum occurring at the surface of the lead and decreasing substantially below 5–10 m. This unstable gradient is a unique characteristic of lead convection. Though the salinity disturbances may be small when ice velocities are large, the buoyancy flux in leads has a major effect on the boundary layer turbulence.
Narrowband structure in HF waves above the electron plasma frequency in the auroral ionosphere

We report high resolution measurements of the frequency‐time structure of HF waves just above the electron plasma frequency in overdense conditions in the auroral ionosphere. Short duration narrowband emissions (HF chirps) are observed whose frequencies predominantly decrease with time. Typical HF Chirp amplitudes are 1 mV/m, typical durations are 100 ms, and typical frequency‐time slopes are 50 kHz/s. The emissions often occur in flocks in which pairs of emissions appear simultaneously at frequencies 300‐2000 Hz apart and drift in parallel. The observed characteristics are consistent with propagating electromagnetic Z‐mode waves.
Warming and salinification of intermediate and deep waters in the Irminger Sea and Iceland Basin in 1997–2006

Recent intra‐decadal changes in temperature and salinity of the Labrador Sea Water and Nordic overflow waters are quantified on the basis of the CTD data from the repeats of the zonal transatlantic section along ∼60°N carried out in 1997, 2002, 2004 and 2006. The revealed changes, in general, point to a rapid transition to the warmer/saltier conditions at the intermediate and deeper levels in the Irminger Sea and Iceland Basin at the section latitude in 1997–2006. In particular, substantial steady warming and salinification of the Iceland–Scotland Overflow Water is revealed in both basins. The latter result means an abrupt reversal or, at least, almost a decade‐long interruption of the long‐term freshening of this water lasted since the mid‐1960s.
Gradient-Particle Size Relations on Quartz Monzonite Debris Slopes in the Mojave Desert

The mean size $$\bar{D}$$ of particles mantling quartz monzonite debris slopes in the Mojave Desert is found to be correlated with slope gradient 5, but the $$S-\bar{D}$$ relation is shown to vary from one debris slope to another as a result of differences in joint spacing and mode of weathering of the underlying quartz monzonite. Unlike debris slopes developed on closely jointed and/or mechanically weak rocks, which we have previously shown to be adjusted to present-day hydraulic processes, those developed on quartz monzonite are only partly adjusted. The degree of adjustment of any part of a debris slope varies inversely with gradient and joint spacing. The correlations between S and $$\bar{D}$$ are due to $$\bar{D}$$ decreasing as debris slopes become better adjusted and to debris slopes becoming better adjusted at lower gradients.
Analysis of charge transport during lightning using balloon‐borne electric field sensors and Lightning Mapping Array

[1] Recently, wide band measurements of the electric field near a lightning flash have been obtained by a balloon-borne electric field sonde or Esonde. This paper develops new techniques for analyzing lightning-associated charge transport in a thundercloud by using both the Esonde data and simultaneous Lightning Mapping Array (LMA) measurements of VHF pulses emitted during lightning breakdown processes. Innovations in this paper include the following: (1) A filtering procedure is developed to separate the background field associated with instrument rotation and cloud charging processes from the lightning-induced electric field change. Because of the abrupt change in the signal caused by lightning, standard filtering techniques do not apply. A new mathematical procedure is developed to estimate the background electric field that would have existed if the lightning had not occurred. The estimated background field is subtracted from the measured field to obtain the lightning-induced field change. (2) Techniques are developed to estimate the charge transport due to lightning. At any instant of time during a cloud-to-ground (CG) flash, we estimate the charge transport by a monopole. During an intracloud (IC) flash, we estimate the charge transport by a dipole. Since the location of the monopole and dipole changes with time, they are referred to as a dynamic monopole and a dynamic dipole. The following physical constraints are used to achieve a unique fit: charge conservation during an IC flash, separation (distance between the CG monopole charge center and the ground and separation between IC dipole charge centers both exceed a minimum threshold), location (charge is placed on lightning channel), and likelihood (after a statistical analysis based on instrument uncertainty, highly unlikely charge locations are excluded). To implement the constraint that the charge is located on the lightning channel, we develop a mathematical object called the “pulse graph. ” Vertices in the graph are pulse locations obtained from the Lightning Mapping Array. Edges in the graph (that is, the pairs of vertices which are connected by line segments) are obtained by joining, in a systematic way, neighboring vertices. One CG and two IC flashes observed on 18 August 2004 near Langmuir Laboratory are analyzed. In the CG flash, initial strokes drained 12 C charge from an altitude of 5 km, while an intermediate stroke discharged 12 C from a higher charge center at 8 km. For the IC flashes, the current flow lagged behind the channel formation by time intervals on the order of 0.1 s, roughly the same time delay observed for lightning optical signals detected by NASA's Lightning Imaging Sensor.
Simultaneous measurements of remote lidar chlorophyll and surface CO2 distributions in the Ross Sea

A comparison between continuous lidar fluorosensor chlorophyll-a measurements and partial pressure of CO2 (pCO2) in surface water is presented. The data were gathered during the XVI Italian Antarctic expedition in the Western Ross Sea and crossing the Southern Ocean. Anticorrelation between CO2 levels and chlorophyll-a determinations was observed throughout the cruise in the late austral summer 2000/01. The survey revealed the presence of high productivity in polynya regions and close to the ice edges. The lidar data, reported here, are consistent with the results of previous campaigns conducted in the same investigated area. The relationship between pCO2 and chlorophyll-a concentration are discussed in terms of biologically driven phenomena responsible for the pCO2 undersaturation with respect to the atmospheric value during the austral summer.
The 2011 Virginia earthquake: What are scientists learning?

Nearly 1 year ago, on 23 August, tens of millions of people in the eastern United States and southeastern Canada were startled in the middle of their workday (1:51 P.M. local time) by the sudden onset of moderate to strong ground shaking from a rare magnitude (M) 5.8 earthquake in central Virginia. Treating the shaking as if it were a fire drill, millions of workers in Washington, D. C. , New York City, and other eastern cities hurriedly exited their buildings, exposing themselves to potentially greater danger from falling bricks and glass; “drop, cover, and hold” would have been a better response. Fortunately, the strong shaking stopped after about 5 seconds and did not cause widespread severe damage or serious injuries. The central Virginia earthquake, among the largest on the eastern seaboard during the approximately 400-year historic record, occurred as the result of reverse slip on a previously unrecognized north-to-northeast striking fault within the Central Virginia seismic zone (CVSZ) (Figure 1a). Many old faults are mapped in the CVSZ, yet no individual strands were previously confirmed to be active. However, persistent low-level seismicity has been observed during historical times, and instrumental recordings since about 1970 detect ongoing distributed seismicity within the CVSZ [Bollinger and Hopper, 1971], which has been identified by the U.S. Geological Survey (USGS) as an area of elevated earthquake hazard since 1976 [Algermissen and Perkins, 1976].
Structure and deformational history of the inner forearc region, Hikurangi subduction margin, New Zealand

Abstract Seismic reflection and outcrop data from the onshore Hikurangi forearc reveal the styles and history of deformation for a c. 3000 km2 region between Dannevirke and Hawke’ s Bay. The data cover the forearc basin, including its western and eastern boundaries, and delineate folds and faults in a late Miocene‐Recent sedimentary sequence. Five seismic horizons, including the basement/Neogene cover unconformity (variable age), base Waipipian (3.7 Ma), base Mangapanian (3.2 Ma), base Nukumaruan (2.6 Ma), and base Castlecliffian (1.6 Ma) were identified using outcrop and well ties. These horizons were traced across the study region to provide information on the geometry, spatial distribution, and timing of structures. To the west, the range‐front fault is predominantly reverse and separates uplifted Torlesse basement of the axial ranges from Neogene forearc basin sediments. Structures within the forearc basin are dominated by north‐northeast‐striking reverse faults and associated asymmetric folds which p.