Miracle-dz/UniFAR-FTUs huggingface dataset:
Methane emission by bubbling from Gatun Lake, Panama

We studied methane emission by bubbling from Gatun Lake, Panama, at water depths of less than 1 m to about 10 m. Gas bubbles were collected in floating traps deployed during 12- to 60-hour observation periods. Comparison of floating traps and floating chambers showed that about 98% of methane emission occurred by bubbling and only 2% occurred by diffusion. Average methane concentration of bubbles at our sites varied from 67% to 77%. Methane emission by bubbling occurred episodically, with greatest rates primarily between the hours of 0800 and 1400 LT. Events appear to be triggered by wind. The flux of methane associated with bubbling was strongly anticorrelated with water depth. Seasonal changes in water depth caused seasonal variation of methane emission. Bubble methane fluxes through the lake surface into the atmosphere measured during 24-hour intervals were least (10-200 mg m{sup -2} d{sup -1}) at deeper sites (>7 m) and greatest (300-2000 mg m{sup -2} d{sup -1}) at shallow sites (<2 m). 37 refs., 11 figs., 5 tabs.
A National Soil Profile Database for Brazil Available to International Scientists

A comprehensive digital soil profile database of Brazil was compiled and is being made available through the Internet. Most of the soil data were obtained from the Radambrasil project and other regional surveys. The database contains information from 5086 profiles distributed over the whole Brazilian territory corresponding to data from 10 034 horizons, each with 31 variables. The variables were chosen to represent different areas of soil science, embracing soil morphological, chemical, mineralogical, and physical attributes. The distribution uniformity of the data was low with sampling densities varying from one profile per 10 000 km 2 to one profile per 1370 km 2 . The access to the database is free and its design allows its use not only by soil scientists but also by those working with agricultural, environmental, and land use issues.
Reconciling differing views of tropical pacific climate change

Recent analyses of global warming projections simulated with global climate models (GCMs) suggest that the tropical Pacific does not become El Nino- or La Nina-like in response to increased greenhouse gases (GHGs). Rather, the physical mechanisms that drive tropical Pacific climate change depart substantially from the El Nino-Southern Oscillation (ENSO) analogy often invoked for interpreting future climate changes [e.g., Knutson and Manabe, 1995; Meehl and Washington, 1996; Cane et al., 1997; Collins et al., 2005; Meehl et al., 2007; Lu et al., 2008; Cox et al., 2004] and past climate changes [e.g. Lea et al., 2001; Koutavas et al., 2002]. This presents an opportunity for reconciling theory, models, and observations. An ENSO analogy typically is invoked for interpreting tropical Pacific climate change because if an external forcing introduces some east-west asymmetry, this asymmetry can be amplified in the same way as interannual perturbations are, through the positive ocean-atmosphere Bjerknes feedback. This then would lead to an altered mean state of the tropical Pacific resembling El Nino or La Nina [Dijkstra and Neelin, 1995]. For instance, the model projections used for the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) anticipate tropical Pacific climate change in response to increased GHGs that has been described as El Nino—like [Meehl et al., 2007]. These models project robust enhanced equatorial warming [Liu et al., 2006; DiNezio et al., 2009] and a weakening of the overturning atmosphere circulation across the tropical Pacific, i.e., the Walker circulation [Vecchi and Soden, 2007], both of which occur during El Nino events. However, these experiments also show a shoaling and sharpening of the equatorial thermocline [Vecchi and Soden, 2007; DiNezio et al., 2009] (Figure 1a). This is in contrast to El Nino events, when the thermocline response is heavily dominated by a relaxed tilt (Figure 1b).
Late Oligocene initiation of the Antarctic Circumpolar Current: evidence from the South Pacific

The Antarctic Circumpolar Current (ACC) is a key feature of the Southern Ocean. Its development may have helped cool Antarctica and initiate Southern Hemisphere glaciation. The deep circulation of the ACC must have been established after both the Tasman gateway (between Antarctica and Australia) and the Drake Passage (between South America and Antarctica) opened. However, estimates for ACC initiation range over 20 m.y. , from the middle Eocene to early Miocene. A new piston core of upper Oligocene to Holocene sediments from the South Pacific has allowed us to delimit the formation of the ACC to the late Oligocene (ca. 25–23 Ma). Upper Oligocene, current-worked sediments and a hiatus to the upper Miocene result from the beginning of the modern ACC flow; i.e., when strong currents and mixing throughout the water column were established. Previously published Nd isotope data date the first intrusion of Pacific water into the Atlantic much earlier. The discrepancy with our results can be reconciled by the different methods measuring different flow regimes. Tracer methods such as Nd are sensitive to relatively small and shallow incursions of water, whereas pelagic erosional regimes require vigorous deep flow.
Predicting River Floodplain and Lateral Channel Migration for Salmon Habitat Conservation 1

Abstract: In this article, we describe a method for predicting floodplain locations and potential lateral channel migration across 82,900 km (491 km2 by bankfull area) of streams in the Columbia River basin. Predictions are based on channel confinement, channel slope, bankfull width, and bankfull depth derived from digital elevation and precipitation data. Half of the 367 km2 (47,900 km by length) of low‐gradient channels (≤ 4% channel slope) were classified as floodplain channels with a high likelihood of lateral channel migration (182 km2, 50%). Classification agreement between modeled and field‐measured floodplain confinement was 85% (κ = 0.46, p < 0.001) with the largest source of error being the misclassification of unconfined channels as confined (55% omission error). Classification agreement between predicted channel migration and lateral migration determined from aerial photographs was 76% (κ = 0.53, p < 0.001) with the largest source of error being the misclassification of laterally migrating channels as non‐migrating (35% omission error). On average, more salmon populations were associated with laterally migrating channels and floodplains than with confined or nonmigrating channels. These data are useful for many river basin planning applications, including identification of land use impacts to floodplain habitats and locations with restoration potential for listed salmonids or other species of concern.
Linear theory and modeling of the Rayleigh‐Taylor instability leading to the occurrence of equatorial spread F

In a test of the generally accepted Rayleigh-Taylor (R-T) instability mechanism for equatorial spread F (ESF) a linear instability growth rate γ RT is derived following the formalism of Haerendel (preprint, 1973) which takes into account the variations of physical parameters along geomagnetic flux tubes. The resulting form of γ RT extends the results of previous work by including direct dependencies on transequatorial neutral winds, zonal electric fields, vertical and horizontal ionospheric density gradients, the presence of an E region, and chemical recombination. Realistic atmospheric and ionospheric density model inputs are used for the first time to make quantitative calculations of R-T growth rates for a range of geophysical conditions. The key result of this study is that time/altitude domains having positive calculated instability growth rates are found to coincide with observed time/altitude patterns of ESF occurrence over both a monthly and a yearly time frame. This success in being able to model the climatological occurrence of ESF lends support to the physical model adopted for the instability mechanism and opens up new avenues of research into ESF predictability on a night-to-night and even an hour-to-hour basis.
Magnetic hysteresis properties of synthetic titanomagnetites

Synthetic titanomagnetites ((1−x)Fe3O4, - xFe2TiO4, 0 ≤ × ≤ 0.6) were prepared by the ceramic oxide method and the equilibrium atmosphere method, and two size fractions were separated out. The first contained particles of size >150 μm, while the second, which was ground in a water slurry, had a mean particle size of about 0. 1μm. The magnetic hysteresis properties, i.e., coercive force HC, remanent coercive force ERC, saturation remanence JRS, JRS/JS, and initial susceptibility x0, were measured at room temperature. The coarse grain samples were found to be magnetically soft (HC ∼ 30 Oe) and the hysteretic properties independent of composition. In contrast, the fine grain samples were extremely hard (HC ∼ 400–2000 Oe) and their magnetic characteristics strongly dependent on composition. When compared with the Stoner-Wohlfarth model for single-domain magnetization, the agreement was good, indicating that these latter samples contain mainly single-domain grains. Samples containing both hard and soft fractions exhibited hysteretic properties that depended on the relative proportions of each size fraction.
Exploring the potential of tree‐ring chronologies from the Trafoi Valley (Central Italian Alps) to reconstruct glacier mass balance

Two tree‐ring chronologies of stone pine (Pinus cembra L.) and two of Norway spruce (Picea abies Karst.) were constructed on the basis of data from three high‐altitude sites in the Trafoi Valley (Central Alps, Italy) to test tree species sensitivity to climate at different sites and to explore the potential of the two species for reconstructing the mass balance of two glaciers in the same region (the Careser and Hintereis glaciers). Influence of climate on tree‐ring growth and on glacier mass variations was tested by means of Pearson's correlation and response functions. At highest altitude sites, both species appeared to be sensitive to July temperatures, while stone pine also showed higher sensitivity than Norway spruce to previous winter precipitation. Comparing the dendrochronological and glaciological series, stone pine showed higher negative correlations with glacier mass balance series than Norway spruce. These different relationships reflect different species responses to climate, and stone pine is potentially useful in reconstructing past glacier mass balance in the Central Alps. Extreme climatic events induce different and even contrasting responses of tree‐ring growth and glacier mass variations and may therefore bias tree‐ring‐based glacier mass balance reconstructions.
Empirical Orthogonal Analysis of Pacific Sea Surface Temperatures

Abstract An empirical orthogonal function analysis has been performed on monthly mean sea surface temperatures for the greater part of the Pacific Ocean between 55°N and 20°S. The analysis identifies the most important modes of seasonal and non-seasonal variability during the period 1949–73. A mode is defined spatially in terms of an empirical orthogonal function which describes the degree of coherence of variation. The function's corresponding coefficient portray the evolution of the mode in time. The seasonal variation is dominated by a mode having a 12-month periodicity and greatest coherence in the higher latitudes. A second important seasonal mode has a period of approximately 6 months and is dominated by deviations in the North Pacific. The most important non-seasonal variation is identified with the, long-recognized El Nino. The spatial pattern of this mode demonstrates the large-scale nature of the El Nino phenomenon. Other important non-seasonal modes are discussed.
Stratospheric nitrous oxide distribution in the southern hemisphere

Nitrous oxide measurements were made in the southern hemisphere (latitude, 42{degree}S to 72{degree}S) as part of the Airborne Antarctic Ozone Experiment (AAOE) in late winter and early spring 1987, covering the altitude range 14-21 km. This paper reports on N{sub 2}O measurements made by the airborne tunable laser absorption spectrometer (atlas), which was flown on board the NASA ER-2 aircraft. Average vertical N{sub 2}O profiles at latitudes 72{degree}S, 54{degree}S, and 42{degree}S are presented and compared, when possible, with equivalent summer profiles. Latitudinal gradients of N{sub 2}O on isentropic surfaces are presented and discussed in terms of their implications about the inhibition of horizontal mixing near the polar vortex. Finally, a large-scale distribution of N{sub 2}O for the region 72{degree}S to 42{degree}S latitude is presented. The reader is directed to the note added in proof regarding the recent recalibration of this data set.
Satellite detection of cloud liquid water over land using polarization differences at 85.5 GHz

A physical retrieval method is described that detects cloud liquid water path (LWP) over land using polarization difference measurements from the Special Sensor Microwave Imager (SSM/I). The brightness temperature difference at 85.5 GHz is divided by the surface emissivity polarization difference to define a normalized polarization difference (NPD). The SSM/I NPD observations are compared to coincident observations of liquid water path from upward looking ground‐based microwave radiometers in Oklahoma and Kansas for November and December of 1994. The comparisons reveal a moderate correlation and nonlinear relationship (which is expected from theory) between the 85.5 GHz NPD and liquid water path. The NPD method is anticipated to be valid over a broad region of the U.S., excluding the southern Mississippi Valley where the surface emissivity polarization differences are negligible. The observational results indicate that the NPD method holds promise for future routine satellite detection and retrieval of cloud LWP over land.
Hydrographic changes in the Canada Basin of the Arctic Ocean, 1979–1996

Hydrographic surveys of the southern Canada Basin have been conducted in winter almost annually since 1979. Coverage has extended 100–200 km beyond the shelf to water depths of 2000–3000 m. Water properties in the upper 1500 m have fluctuated over intervals of a few years, and progressive changes have taken place during the 17 years of this study. At depths below the warm core of the Atlantic layer, water is warmer and fresher now than in the early 1980s. These changes reflect a thickening of the warm core at its lower boundary by more than 100 m. The maximum temperature of the Atlantic water has decreased by 0.06°C, and the salinity at the maximum has decreased by 0.027. Above the Atlantic layer the lower halocline (34.5 isohaline) has cooled by 0.12°C, a change which may indicate that ventilation of this level on the European side of the Arctic has been more effective in recent years. A good correlation between temperature fluctuations on the 34.5 isohaline and depth fluctuations of the lower 0°C isotherm suggests common forcing of both parameters. Variation in the flow through the Barents Sea into the Arctic is proposed as that common influence. The upper halocine has warmed by 0.15°C on the 33.5 isohaline. This trend could be a consequence of decreasing ventilation of the upper halocline over the broad shallow shelves on the Pacific side of the Arctic Ocean and may be related to the decrease in the strength of the Siberian High during the same time. The net result of changes in the hydrography of the Canada Basin has been an increase of 0.2 GJ m−2 in stored sensible heat, an amount sufficient to melt about 0.7 m of sea ice. The bulk of the increase results from the thickening of the Atlantic layer below 500 m.
Simulating Hydrodynamics in the Upper Charlotte Harbor and its Major Tributaries in Florida

Abstract Charlotte Harbor is one of major estuaries in Florida. The upper portion of the estuary receives freshwater inflows mainly from the Peace and Myakka Rivers. To study the hydraulic interactions between the Upper Charlotte Harbor (UCH) and its major tributaries, a multi-block model was used to simulate hydrodynamics and salinity transport processes in a simulation domain that includes the UCH, the Lower Peace River (LPR), the Lower Myakka River (LMR), the Shell Creek, and a portion of the Myakkahatchee Creek. In the modeling study, the simulation domain is split into a 3D simulation block and several 2DV blocks. The 3D block includes the UCH and the most downstream portions of the LPR and LMR, while the 2DV blocks contain the rest of the tributaries. All the blocks are patched together without any overlaps. The coupled model solves 3D RANS equations for the 3D block, but laterally averaged RANS equations for the 2DV blocks that consist of narrow and braided tributaries. Both 3D and 2DV sub-models use an efficient semi-implicit, flux-based finite difference method. The dynamic coupling is facilitated using a free-surface correction method, in which matrixes for the water surface correction in both the 3D and 2DV sub-domains are solved simultaneously after they are merged together. Model simulations demonstrated that the multi-block model is an efficient tool for simulating hydrodynamics in a very complex environment and the model application to the LPR-LMR-UCH system is successful.
Numerical simulation of three‐dimensional, time‐averaged flow structure at river channel confluences

Current confluence research emphasizes three broad controls on flow structure generation: (1) planform curvature; (2) topographic steering; and (3) anisotropic turbulence associated with flow separation and shear layer dynamics. The relative importance of these processes in explaining observed flow structures is controversial, a situation that may be related to the fact that different investigators have examined different confluence configurations. This paper uses a three‐dimensional numerical model, with a fully elliptic solution, a free surface treatment, and a turbulence model based on a renormalized group (RNG) to help to provide a physically based explanation of the controls upon flow structure generation for both a laboratory (rectangular) and a field confluence (the confluence of the Kaskaskia River and Copper Slough) and to identify the particular conditions under which particular flow structures are observed. Results suggest that an analogy with back‐to‐back meanders is possible for symmetrical configurations but that there will be progressive divergence from this state as confluence asymmetry increases. In asymmetric situations a dual‐cell structure may be limited to the immediate vicinity of the junction because of the effects of streamline curvature and topographic steering. These differences can be explained by consideration of the dynamic pressure field, which may be specific to each confluence configuration. As such, this study partially reconciles differing views over what controls time‐averaged flow structures in river channel confluences, although further research into the interaction of these processes with instantaneous velocity fluctuations is required.
Regional mortality differentials in Greece by selected causes of death: 2006–2008

Deaths due to neoplasms and diseases of the circulatory and the respiratory system represent 80% of all deaths in Greece. In the context of dearth of statistical analysis of spatial patterns of cause-specific mortality in Greece, this paper aims at studying the distribution and structure of appropriate mortality measures for the above mentioned causes of death at prefecture level. To achieve this, official statistics on deaths (2006–2008) and population (2007) are employed and Standardized Mortality Ratios (SMRs) by gender and cause of death are estimated using as ‘standard’ mortality schedule the national age-sex and cause-specific death rates. Estimation of Moran's I statistic revealed the existence of significant positive spatial autocorrelation for neoplasms and circulatory diseases. Empirical Bayes procedures were employed to adjust SMR values which, although show less dispersion, were close to the original estimates. The thematic maps depict regions with relatively high (SMRs > 100) or low (SMRs < 100) mortality and their significance levels, indicating that spatial patterns exhibit many similarities between sexes for each cause of death. SMRs for neoplasms and circulatory diseases show a roughly similar tendency; lower mortality compared to the country's average in southern and western Greece and the islands, and higher mortality in northern Greece, especially in the Region of East Macedonia and Thrace. Patterns due to respiratory diseases, on the other hand, differ somewhat but the corresponding relative risks are not as significant. Thorough observation and analysis of the conditions prevailing in northern Greece is needed to identify factors exacerbating ill health.
STRUCTURAL SIGNIFICANCE OF GRAVITY SURVEYS IN THE VIRGINIA CITY—MOUNT ROSE AREA, NEVADA AND CALIFORNIA

Gravity surveys were made in the Mount Rose and Virginia City quadrangles to investigate the concealed Cenozoic structure of the alluviated basins and to explore for significant gravity differences between basins and ranges. The gravity data have been computed as complete Bouguer anomalies, which incorporate corrections for all the accurately assessible factors affecting gravity values, including topographic irregularities but not isostatic compensation. Gravity variations in the basins are closely related to changes in thickness of Cenozoic sedimentary rocks and alluvium in the basins. The gravity data indicate that light Cenozoic sedimentary rocks in Washoe Valley are at least 1800 feet thick; that the sediments in the northern part of Steamboat Valley are only about 600 feet thick and thin gradually eastward but thin abruptly to the west near Steamboat Hills; that east of Reno, between Sparks and the Virginia Range, sediments are roughly 2800 feet thick and thin abruptly about half a mile west of the range; and that in the basin west of Reno sediments are locally 1800 feet or more thick. The variations in thickness reflect important structural deformation in the basins. The late Cenozoic structures that separate the basins from the mountains are a complex of contemporaneous faults and folds; folding is predominant in some areas and normal faulting in others. From the eastern boundary of the area surveyed, the gravity values decrease westward about 1 mgal per mile, a total of 30 mgals, to a minimum at the east side of the Carson Range of the Sierra Nevada and then increase toward the main Sierra block. There is little or no gravity expression of the Virginia Range or the Carson Range relative to sediment-free parts of the basins adjacent to the ranges. Gravity measurements of the Coast and Geodetic Survey combined with the present measurements demonstrate that the Bouguer anomaly from San Francisco eastward shows a general inverse relationship to elevation but is a minimum along the east side of the Carson Range rather than at the main summit of the Sierra. This gravity profile may be the result of a thickening of the earth9s crust eastward beneath the higher part of the continent, combined with a smaller effect from greater-than-average amounts of granitic rock in the crust of the Sierran region.
Recent extreme air temperature changes in Montenegro

The studies show that the changes in intensity and frequency of the extreme weather events have been registered in many regions of the world. This paper gives an analysis of the change of 12 air temperature parameters, out of which 9 are climate indices. The indices suggested by WMO-CCL/CLIVAR have been used in order to investigate the changes in temperature extremes. The research related to the topic has been carried out by using the data from 23 meteorological stations for the 1951 - 2010 period and calculations have been done on the seasonal level. The results show that the maximum and minimum air temperatures, which have “warmer values”, are becoming more frequent on the territory of Montenegro which corresponds to the general idea of global warming.