Evaluation of the applicability of a fuzzy index of ecosystem integrity (FINE) to characterize the status of Tyrrhenian lagoons

The new index FINE, a multimetric, fuzzy-based index for the evaluation of environmental quality for Mediterranean transitional waters, was calculated using biotic data gathered between 2000 and 2006 at 15 stations in 4 Tyrrhenian transitional water ecosystems (Orbetello Lagoon, Padrongiano Delta, Stagno di S. Teodoro, and Stagno di Tortolì), i.e. in a different biogeographic sub-province respect to the one in which the index was developed and validated. The rationale of FINE is that certain attributes, selected on the basis of established principles of benthic ecology, are fundamental for lagoon ecosystem function. A set of other indices (Simpson's 1-lambda', the W-statistics, AMBI, and BOPA) was also calculated and compared to FINE outputs. FINE, 1-lambda', and the W-statistics were significantly correlated with sedimentary organic matter content. Some stations were unequivocally assigned to the same ecological status, independently from the index used; for others, some discrepancies were evident. Mediterranean transitional waters probably share ecosystem complexities which are not yet fully captured by indices developed and validated elsewhere.     

Decadal prediction skill in the GEOS-5 forecast system

A suite of decadal predictions has been conducted with the NASA Global Modeling and Assimilation Office’s (GMAO’s) GEOS-5 Atmosphere–Ocean general circulation model. The hind casts are initialized every December 1st from 1959 to 2010, following the CMIP5 experimental protocol for decadal predictions. The initial conditions are from a multi-variate ensemble optimal interpolation ocean and sea-ice reanalysis, and from GMAO’s atmospheric reanalysis, the modern-era retrospective analysis for research and applications. The mean forecast skill of a three-member-ensemble is compared to that of an experiment without initialization but also forced with observed greenhouse gases. The results show that initialization increases the forecast skill of North Atlantic sea surface temperature compared to the uninitialized runs, with the increase in skill maintained for almost a decade over the subtropical and mid-latitude Atlantic. On the other hand, the initialization reduces the skill in predicting the warming trend over some regions outside the Atlantic. The annual-mean atlantic meridional overturning circulation index, which is defined here as the maximum of the zonally-integrated overturning stream function at mid-latitude, is predictable up to a 4-year lead time, consistent with the predictable signal in upper ocean heat content over the North Atlantic. While the 6- to 9-year forecast skill measured by mean squared skill score shows 50 % improvement in the upper ocean heat content over the subtropical and mid-latitude Atlantic, prediction skill is relatively low in the subpolar gyre. This low skill is due in part to features in the spatial pattern of the dominant simulated decadal mode in upper ocean heat content over this region that differ from observations. An analysis of the large-scale temperature budget shows that this is the result of a model bias, implying that realistic simulation of the climatological fields is crucial for skillful decadal forecasts.     

Diel activity and short‐distance movement pattern of the European spiny lobster,Palinurus elephas,acoustically tracked

This paper presents the results of the application of an ultrasonic telemetry system to the investigation of short‐term movements in the European spiny lobster, Palinurus elephas, in a coastal area of NW Sicily (Central Mediterranean Sea). Ten lobsters were tagged with miniaturized transmitters and released over a favourable habitat and their movements then recorded by means of nine automated receivers with the objective of investigating post‐release displacement, home‐range extension, movement patterns, activity rhythm and the influence of lunar light intensity on lobster activity. Acoustic detection data were used to assess activity and home range using estimates of horizontal and vertical movements and minimum convex polygons, respectively. Continuous wavelet transform (CWT) analysis was applied to time series of position data. Acoustic data from five of 10 lobsters were successfully recorded across a 78‐day study period between April and June 2008. All of them displayed an activity pattern characterized by diurnal sheltering and nocturnal foraging, with higher activity (i.e., longer distances travelled) at night. Their home range measured between 1629 and 8641 m², and all lobsters relocated every 4.6 days on average, probably in search of unexploited feeding grounds. For this reason we hypothesize a nomadic movement pattern for our tagged lobsters. CWT analyses highlighted a 24‐h periodicity in lobster activity, with higher activity from sunset to sunrise. No clear influence of moon phase on lobster activity was detected.     

Viscous Newtonian laminar flow in a rectangular channel: application to Etna lava flows

 We introduce a 3D model for near-vent channelized lava flows. We assume the lava to be an isothermal Newtonian liquid flowing in a rectangular channel down a constant slope. The flow velocity is calculated with an analytical steady-state solution of the Navier-Stokes equation. The surface velocity and the flow rate are calculated as functions of the flow thickness for different flow widths, and the results are compared with those of a 2D model. For typical Etna lava flow parameters, the influence of levees on the flow dynamics is significant when the flow width is less than 25 m. The model predicts the volume flow rate corresponding to the surface velocity, taking into account that both depend on flow thickness. The effusion rate is a critical parameter to evaluate lava flow hazard. We propose a model to calculate the effusion rate given the lava flow width, the topograhic slope, the lava density, the surface flow velocity, and either the lava viscosity or the flow thickness. Received: 20 January 1998 / Accepted: 8 January 1999     

Debris flow and slide deposits at the top of the Internal Liguride ophiolitic sequence, Northern Apennines, Italy: A record of frontal tectonic erosion in a fossil accretionary wedge

Abstract In the Northern Apennines, the Internal Liguride units are characterized by an ophiolite sequence that represents the stratigraphic base of a late Jurassic–early Paleocene sedimentary cover. The Bocco Shale represents the youngest deposit recognized in the sedimentary cover of the ophiolite and can be subdivided into two different groups of deep sea sediments. The first group is represented by slide, debris flow and high density turbidity current-derived deposits, whereas the second group consists of thin-bedded turbidites. Facies analysis and provenance studies indicate, for the former group, small and scarcely evoluted flows that rework an oceanic lithosphere and its sedimentary cover. We interpret the Bocco Shale as an ancient example of a deposit related to the frontal tectonic erosion of the accretionary wedge slope. The frontal tectonic erosion resulted in a large removal of materials, from the accretionary wedge front, that was reworked as debris flows and slide deposits sedimented on the lower plate above the trench deposits. The frontal tectonic erosion was probably connected with subduction of oceanic crust characterized by positive topographic relief. This interpretation can be also applied for the origin of analogous deposits of Western Alps and Corsica.     

Predation impact on the meiobenthic harpacticoidCanuella perplexa in a lagoon of the Po River Delta,Italy

The impact of predation by juvenile marbled gobies,Pomatoschistus marmoratus, on the meiobenthic harpacticoid copepodCanuella perplexa was investigated at a subtidal station located in a shallow-water, brackish embayment of the Po River delta, northern Italy, in summer and fall 1978. In august, predation mainly centered on adults, with a very large number of prey for each predator; the energy supplied by the harpacticoid is high enough to sustain, almost entirely, the gobies’ daily energy requirement. The situation is different in September and October, when the adult copepod population declines dramatically and predation is shifted to less energy-providing copepodites and marbled gobies sensibly widen their prey spectrum.C. perplexa showed alterations of biological parameters, such as clutch size and average brood size, to cope with such a heavy predation pressure.     

The lattice energy of forsterite. Charge distribution and formation enthalpy of the SiO 4 4− ion

In the lattice energy expression of forsterite, based on a Born-Mayer (electrostatic+repulsive+dispersive) potential, the oxygen charge z _o, the hardness parameter ρ and the repulsive radii r _Mg and r _Si appear as unknown parameters. These were determined by calculating the first and second partial derivatives of the energy with respect to the cell edges, and equalizing them to quantities related to the crystal elastic constants; the overdetermined system of equations was solved numerically, minimizing the root-mean-square deviation. To test the results obtained, the SiO ₄ ^4? ion was assumed to move in the unit-cell, and the least-energy configuration was sought and compared with the experimental one. By combining the two methods, the optimum set of parameters was: z _o=?1.34, ρ=0.27 Å, r _Mg=0.72 Å, r _Si=0.64 Å. The values ?8565.12 and ?8927.28 kJ mol^?1 were obtained, respectively, for the lattice energy E _Land for its ionic component E _L ⁰ ,which accounts for interactions between Mg²⁺ and SiO ₄ ^4? ions only. The charge distribution calculated on the SiO ₄ ^4? ion was discussed and compared with other results. Using appropriate thermochemical cycles, the formation enthalpy and the binding energy of SiO ₄ ^4? were estimated to be: ΔH _f(SiO ₄ ^4? )=2117.6 and E(SiO ₄ ^4? )=708.6 kJ mol^?1, respectively.     

Generalized Regularization Techniques with Constraints for the Analysis of Solar Bremsstrahlung X-ray Spectra

Hard X-ray spectra in solar flares provide knowledge of the electron spectrum that results from acceleration and propagation in the solar atmosphere. However, the inference of the electron spectra from solar X-ray spectra is an ill-posed inverse problem. Here, we develop and apply an enhanced regularization algorithm for this process making use of physical constraints on the form of the electron spectrum. The algorithm incorporates various features not heretofore employed in the solar flare context: Generalized Singular Value Decomposition (GSVD) to deal with different orders of constraints; rectangular form of the cross-section matrix to extend the solution energy range; regularization with various forms of the smoothing operator; and preconditioning of the problem. We show by simulations that this technique yields electron spectra with considerably more information and higher quality than previous algorithms.     

Mesozoic to Tertiary tectonic history of the Mirdita ophiolites, northern Albania

Abstract In this paper, a summary of the tectonic history of the Mirdita ophiolitic nappe, northern Albania, is proposed by geological and structural data. The Mirdita ophiolitic nappe includes a subophiolite mélange, the Rubik complex, overlain by two ophiolite units, referred to as the Western and Eastern units. Its history started in the Early Triassic with a rifting stage followed by a Middle to Late Triassic oceanic opening between the Adria and Eurasia continental margins. Subsequently, in Early Jurassic time, the oceanic basin was affected by convergence with the development of a subduction zone. The existence of this subduction zone is provided by the occurrence of the supra‐subduction‐zone‐related magmatic sequences found in both the Western and Eastern units of the Mirdita ophiolitic nappe. During the Middle Jurassic, continuous convergence resulted in the obduction of the oceanic lithosphere, in two different stages – the intraoceanic and marginal stages. The intraoceanic stage is characterized by the westward thrusting of a young and still hot section of oceanic lithosphere leading to the development of a metamorphic sole. In the Late Jurassic, the marginal stage developed by the emplacement of the ophiolitic nappe onto the continental margin. During this second stage, the emplacement of the ophiolites resulted in the development of the Rubik complex. In the Early Cretaceous, the final emplacement of the ophiolites was followed by the unconformable sedimentation of the Barremian–Senonian platform carbonate. From the Late Cretaceous to the Middle Miocene, the Mirdita ophiolitic nappe was translated westward during the progressive migration of the deformation front toward the Adria Plate. In the Middle to Late Miocene, a thinning of the whole nappe pile was achieved by extensional tectonics, while the compression was still active in the westernmost areas of the Adria Plate. On the whole, the Miocene deformations resulted in the uplift and exposition of the Mirdita ophiolites as observed today.