Integrated assessment of smallholder farming’s vulnerability to drought in the Brazilian Semi-arid: a case study in Ceará

Smallholder farming is among the most vulnerable sectors due to its great social and economic sensitivity. Despite future climate change, current climate variability is already an issue of concern that justifies adaptation efforts. In Brazil, the Semi-Arid Region is a climate hotspot, well known for both historic socioeconomic setbacks, and agriculture failures caused by dry spells and severe droughts. In 2010, the Brazilian government enacted the National Policy on Climate Change, which states as one of its key goals the identification of vulnerabilities and the adoption of adequate measures of adaptation to climate change. The improvement of vulnerability assessment tools is a response to the growing demand of decision makers for regular information and indicators with high spatial and temporal resolution. This article aims at undertaking a comparative assessment of smallholder farming’s vulnerability to droughts. An integrated assessment system has been developed and applied to seven municipalities located in the Brazilian Semi-Arid Region (within the State of Ceará). Results show regional vulnerability contrasts driven by institutional and socioeconomic factors, beyond climatic stressors.     

Confirmation of mass-independent Ni isotopic variability in iron meteorites

We report high-precision analyses of internally-normalised Ni isotope ratios in 12 bulk iron meteorites. Our measurements of ⁶⁰Ni/⁶¹Ni, ⁶²Ni/⁶¹Ni and ⁶⁴Ni/⁶¹Ni normalised to ⁵⁸Ni/⁶¹Ni and expressed in parts per ten thousand (?) relative to NIST SRM 986 as and , vary by 0.146, 0.228 and 0.687, respectively. The precision on a typical analysis is 0.03?, 0.05? and 0.08? for , and , respectively, which is comparable to our sample reproducibility. We show that this ‘mass-independent’ Ni isotope variability cannot be ascribed to interferences, inaccurate correction of instrumental or natural mass-dependent fractionation, fractionation controlled by nuclear field shift effects, nor the influence of cosmic ray spallation. These results thus document the presence of mass-independent Ni isotopic heterogeneity in bulk meteoritic samples, as previously proposed by Regelous et al. (2008) (EPSL 272, 330-338), but our new analyses are more precise and include determination of ⁶⁴Ni. Intriguingly, we find that terrestrial materials do not yield homogenous internally-normalised Ni isotope compositions, which, as pointed out by Young et al. (2002) (GCA 66, 1095-1104), may be the expected result of using the exponential (kinetic) law and atomic masses to normalise all fractionation processes. The certified Ni isotope reference material NIST SRM 986 defines zero in this study, while appropriate ratios for the bulk silicate Earth are given by the peridotites JP-1 and DTS-2 and, relative to NIST SRM 986, yield deviations in , and of −0.006?, 0.036? and 0.119?, respectively. There is a strong positive correlation between and in iron meteorites analyses, with a slope of 3.03 ± 0.71. The variations of Ni isotope anomalies in iron meteorites are consistent with heterogeneous distribution of a nucleosynthetic component from a type Ia supernova into the proto-solar nebula.     

Imaging the recent sediment dynamics of the Galicia Bank region (Atlantic,NW Iberian Peninsula)

Multibeam bathymetry, high resolution multi-channel, and very high resolution single-channel (3.5 kHz) seismic records were used to depict the complex geomorphology that defines the Galicia Bank region (Atlantic, NW Iberian Peninsula). This region (≈620–5,000 m water depth) is characterized by a great variety of features: structural features (scarps, highs, valleys, fold bulges), fluid dynamics-related features (structural undulations and collapse craters), mass-movement features (gullies, channels, mass-flow deposits, slope-lobe complexes, and mass-transport deposits), bottom-current features (moats, furrows, abraded surface, sediment waves, and drifts), (hemi)pelagic features, mixed features (abraded surfaces associated to mixed sediments) and bioconstructions. These features represent architectural elements of four sedimentary systems: slope apron, contouritic, current-controlled (hemi)pelagic, and (hemi)pelagic. These systems are a reflection of different sedimentary processes: downslope (mass transport, mass flows, turbidity flows), alongslope (bottom currents of Mediterranean Outflow Water, Labrador Sea Water, North Atlantic Deep Water, and Lower Deep Water), vertical settling, and the interplay between them. The architectural and sediment dynamic complexities, for their part, are conditioned by the morphostructural complexity of the region, whose structures (exposed scarps and highs) favor multiple submarine sediment sources, affect the type and evolution of the mass-movement processes, and interact with different water masses. This region and similar sedimentary environments far from the continental sediment sources, as seamounts, are ideal zones for carrying out submarine source-to-sink studies, and can represent areas subject to hazards, both geologic and oceanographic in origin.     

Etropus crossotus, an annual flatfish species; age and growth of the fringed flounder in South Carolina

Fringed flounder, Etropus crossotus, a small flatfish common along the southeastern coast of the US, were collected along the South Carolina coast in the fall of 1992, and in the North Inlet estuary from August 1992 until July 1994. Standard length was 82% of total length and the relationship between standard length and wet weight showed near-isometric growth with no significant differences between males and females. Dry weight was 21% of wet weight and ash-free dry weight 14% of wet weight with no significant differences between sexes. Daily increments in the sagittal otoliths were used for age determination. No annual structures could be identified. The maximum age was about 14.5 months. Age-at-length was not different between the sexes. The relationship between age and length was exponential, with age (in days) equalling an e power of 4.242 + 0.135 × standard length (in cm). Back-calculated hatch dates and catches of early juveniles indicated a spawning season that lasted from March to October. Females started to be sexually mature at 7 to 7.5 cm standard length, but 50% maturity was reached at 8 to 8.5 cm. Females could grow to that size within one spawning season. Individuals hatched early in the spawning season could produce eggs in the latter portion of that season's spawning period.     

On poloidal mode coupling in the continuous spectrum of 2D equilibria

The continuous spectrum of linear ideal MHD is determined analytically in 2D magnetostatic models for coronal loops and arcades by means of a perturbation expansion. Poloidal mode coupling, induced by non-circularity of the cross-sections of the magnetic surfaces and/or variation of the plasma density along the magnetic field lines, is shown to occur in first order. The coupling is most pronounced on and near rational surfaces for particular poloidal and toroidal mode numbers and produces gaps in the continuous spectrum of ideal MHD.     

ALH 82102: An Antarctic meteorite embedded partly in ice

Abstract We measured the concentrations of F, Cl, Br and I in two different aliquots of the meteorite ALH 82102. This H5 chondrite was recovered at the Allan Hills region, while it was partially embedded in the ice. One aliquot was taken from that part of the surface of the meteorite that was still in the ice, and the other one was taken from the side, which was poking out of the ice. Both aliquots are highly, and nearly to the same degree, contaminated with halogens. The observed enrichments occurred mainly during the time the meteorite was lying on the surface of the ice by deposition and/or adsorption of aerosols, salts, and gaseous components. A contamination during the time it was covered by the ice is unlikely. We conclude, therefore, that this meteorite was not always buried in the ice during its “residence time” on Earth. In order to accumulate the observed contamination, it had to be on the surface of the ice part of the time between its fall onto the Earth and its collection. The age of the ice surrounding the meteorite cannot be equal to the measured terrestrial age of ALH 82102.     

Does the Fornax dwarf spheroidal have a central cusp or core?

The dark matter dominated Fornax dwarf spheroidal has five globular clusters orbiting at ∼1 kpc from its centre. In a cuspy cold dark matter halo the globulars would sink to the centre from their current positions within a few Gyr, presenting a puzzle as to why they survive undigested at the present epoch. We show that a solution to this timing problem is to adopt a cored dark matter halo. We use numerical simulations and analytic calculations to show that, under these conditions, the sinking time becomes many Hubble times; the globulars effectively stall at the dark matter core radius. We conclude that the Fornax dwarf spheroidal has a shallow inner density profile with a core radius constrained by the observed positions of its globular clusters. If the phase space density of the core is primordial then it implies a warm dark matter particle and gives an upper limit to its mass of ∼0.5 keV, consistent with that required to significantly alleviate the substructure problem.     

3D fold growth rates

Geological folds are inherently 3D structures; therefore, they also grow in three dimensions. Here, fold growth in all three dimensions is quantified by numerically simulating upright single‐layer folds in 3D Newtonian media. Horizontal uniaxial shortening leads to a buckling instability, which grows from a point‐like initial perturbation in all three dimensions by fold amplification (vertical), fold elongation (parallel to fold axis) and sequential fold growth (parallel to shortening direction) of secondary (and further) folds adjacent to the initial isolated fold. The two lateral directions exhibit similar averaged growth rates, leading to bulk fold structures with aspect ratios in map view close to 1. However, fold elongation is continuous with increasing bulk shortening, while sequential fold growth exhibits jumps whenever a new sequential fold appears and the bulk fold structure therefore suddenly occupies more space. Compared with the two lateral growth directions, fold amplification exhibits a slightly higher growth rate.     

Managing coastal evolution in a more sustainable manner. The Conscience approach

This paper summarises the main findings of the Conscience research project, whose primary objective was to define and validate, through pilot applications, a methodology to support the implementation, for European coasts, of concepts such as coastal resilience, favorable sediment status, strategic sediment reservoirs and coastal sediment cells. The Conscience conceptual framework to managing coastal erosion has proved to be an efficient tool, because it provides a consistent approach where objective (data) and subjective (desired status) information are analyzed and compared from the standpoint of a consensus target (objective). Moreover, this is done using the best available knowledge and observations, considering always their level of uncertainty, to conduct a sustainable management policy for coastal erosion. The methodology has been tested in field cases from The Netherlands, Poland, Romania, Spain, United Kingdom and Ireland, to cover different time and space scales, together with a wide range of processes and different management objectives.