Storyline description of Southern Hemisphere midlatitude circulation and precipitation response to greenhouse gas forcing

As evidence of climate change strengthens, knowledge of its regional implications becomes an urgent need for decision making. Current understanding of regional precipitation changes is substantially limited by our understanding of the atmospheric circulation response to climate change, which to a high degree remains uncertain. This uncertainty is reflected in the wide spread in atmospheric circulation changes projected in multimodel ensembles, which cannot be directly interpreted in a probabilistic sense. The uncertainty can instead be represented by studying a discrete set of physically plausible storylines of atmospheric circulation changes. By mining CMIP5 model output, here we take this broader perspective and develop storylines for Southern Hemisphere (SH) midlatitude circulation changes, conditioned on the degree of global-mean warming, based on the climate responses of two remote drivers: the enhanced warming of the tropical upper troposphere and the strengthening of the stratospheric polar vortex. For the three continental domains in the SH, we analyse the precipitation changes under each storyline. To allow comparison with previous studies, we also link both circulation and precipitation changes with those of the Southern Annular Mode. Our results show that the response to tropical warming leads to a strengthening of the midlatitude westerly winds, whilst the response to a delayed breakdown (for DJF) or strengthening (for JJA) of the stratospheric vortex leads to a poleward shift of the westerly winds and the storm tracks. However, the circulation response is not zonally symmetric and the regional precipitation storylines for South America, South Africa, South Australia and New Zealand exhibit quite specific dependencies on the two remote drivers, which are not well represented by changes in the Southern Annular Mode

The first joint ESGAR/ ESPR consensus statement on the technical performance of cross-sectional small bowel and colonic imaging

Objectives: To develop guidelines describing a standardised approach to patient preparation and acquisition protocols for magnetic resonance imaging (MRI), computed tomography (CT) and ultrasound (US) of the small bowel and colon, with an emphasis on imaging inflammatory bowel disease. Methods: An expert consensus committee of 13 members from the European Society of Gastrointestinal and Abdominal Radiology (ESGAR) and European Society of Paediatric Radiology (ESPR) undertook a six-stage modified Delphi process, including a detailed literature review, to create a series of consensus statements concerning patient preparation, imaging hardware and image acquisition protocols. Results: One hundred and fifty-seven statements were scored for agreement by the panel of which 129 statements (82 %) achieved immediate consensus with a further 19 (12 %) achieving consensus after appropriate modification. Nine (6 %) statements were rejected as consensus could not be reached. Conclusions: These expert consensus recommendations can be used to help guide cross-sectional radiological practice for imaging the small bowel and colon. Key points: • Cross-sectional imaging is increasingly used to evaluate the bowel • Image quality is paramount to achieving high diagnostic accuracy • Guidelines concerning patient preparation and image acquisition protocols are provided

Data Service Platform for Sentinel-2 Surface Reflectance and Value-Added Products: System Use and Examples

This technical note presents the first Sentinel-2 data service platform for obtaining atmospherically-corrected images and generating the corresponding value-added products for any land surface on Earth. Using the European Space Agency’s (ESA) Sen2Cor algorithm, the platform processes ESA’s Level-1C top-of-atmosphere reflectance to atmospherically-corrected bottom-of-atmosphere (BoA) reflectance (Level-2A). The processing runs on-demand, with a global coverage, on the Earth Observation Data Centre (EODC), which is a public-private collaborative IT infrastructure in Vienna (Austria) for archiving, processing, and distributing Earth observation (EO) data. Using the data service platform, users can submit processing requests and access the results via a user-friendly web page or using a dedicated application programming interface (API). Building on the processed Level-2A data, the platform also creates value-added products with a particular focus on agricultural vegetation monitoring, such as leaf area index (LAI) and broadband hemispherical-directional reflectance factor (HDRF). An analysis of the performance of the data service platform, along with processing capacity, is presented. Some preliminary consistency checks of the algorithm implementation are included to demonstrate the expected product quality. In particular, Sentinel-2 data were compared to atmospherically-corrected Landsat-8 data for six test sites achieving a R2 = 0.90 and Root Mean Square Error (RMSE) = 0.031. LAI was validated for one test site using ground estimations. Results show a very good agreement (R2 = 0.83) and a RMSE of 0.32 m2/m2 (12% of mean value)

Reproductive traits of the invasive species Acacia dealbata Link. in the northern Mediterranean basin

Among the many exotic plants introduced in the last two centuries in Northern Mediterranean Basin Acacia dealbata Link. is one of the most invasive. Despite its presence in the region since many years, it has not yet been investigated how the species has established itself and has formed small forests. In this study, we aimed to gather data on reproductive trait of the invasive species A. dealbata at the northern limit of the Mediterranean bioclimatic region. In six naturalized populations, fruit and seed set were estimated and seed germination was tested in laboratory. Two out of the six populations failed to set fruits, and the fruit set was always low as observed in other invaded areas of the world. Only three populations produced germinating seeds whose rates were comparable to other invasive areas. The seeds may constitute a long-lasting seed bank that may favour the colonization of the species in areas disturbed by external factors. In conclusion, the reproductive system may contributes only partially to the spread and invasiveness of the species in the Northern Mediterranean basin, while the plant to spread itself adopts also other vegetative strategies

Synthesis and characterization of mixed oxide nanowires for gas sensing

A healthy and long-lasting life is the utmost wish of any living being thus aging. The aging phenomenon cannot be stopped but may be controlled to some extent when we live in appropriate environments. Usually, the outdoor environment is polluted by two means natural events (windblown dust, volcano eruptions, etc.) and man-made ones (burning of facile fuels, factories, volatile organic compounds, etc.). Pollution due to harmful air such as sulfur oxides (SO2), nitrogen oxides (NOX), carbon monoxide (CO), ammonia (NH3), methane (CH4), and volatile organic compounds (VOCs) is one of the significant issues since it is more sensitive to compromising the natural ecosystem and environment. So, exposure to these compounds worsens the aging phenomena of the living being (headache, fainting, skin and eye irradiation, respiratory infections, heart disease, lung cancer, and even superficial death). Therefore, it is necessary the detection these compounds in the environment. Accordingly, metal oxides (MOXs) gas sensors have conventionally been employed to detect and quantify harmful gases in both indoor and outdoor environments. However, one of the major problems with these sensors is achieving selective detection. Herein, we propose a novel design with two metal oxides (ZnO and Co3O4) that provide very high gas response together with superior selectivity. The proposed structure is a one-dimensional (1D) metal oxide composite; Co3O4/ZnO nanowires. The composite was prepared by in-situ thermal oxidation of metallic Co thin layer (50 nm) and evaporation of ZnO powder at a temperature of 800 ᵒC at a pressure of 0.15 mbar. The pressure was maintained by a controlled mixture of O2 and Ar. The morphological, compositional, and structural analyses are evidence of the successful growth of the Co3O4/ZnO composite nanowire with the root of Co3O4 and the tip with Pt (catalyzer) and Co3O4. The gas sensing characterization shows exciting sensing functionality towards acetone (C3H6O) compared to that of tested gases (C2H5OH, H2S, NH3, CO, NO2, and H2). The reported highest response (ΔG/G; G is the conductance) was above the value of 5000 toward 50 ppm (parts per million) C3H6O at 40 RH% air when working at 250 °C with the potential of detecting sub ppb (parts per billion) concentration levels of C3H6O. The very high C3H6O sensing performance together with exceptionally high selectivity of the sensor ascribed to Pt nanoparticle and the Co3O4 section on the tip of the Co3O4/ZnO. Moreover, the formation of heterojunctions, synergistic gas sensing, and the catalytic activity of the proposed design enhances the response of the sensors. Accordingly, scanning electron microscopic (SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) characterization, and the sensing mechanisms are comprehensively discussed at the conference

Sea surface pCO2 and O2 in the Southern Ocean during the austral fall, 2008

The physical and biological processes controlling surface mixed layer pCO2 and O2 were evaluated using in situ sensors mounted on a Lagrangian drifter deployed in the Atlantic sector of the Southern Ocean (∼50°S, ∼37°W) during the austral fall of 2008. The drifter was deployed three times during different phases of the study. The surface ocean pCO2 was always less than atmospheric pCO2 (−50.4 to −76.1 μatm), and the ocean was a net sink for CO2 with fluxes averaging between 16.2 and 17.8 mmol C m−2 d−1. Vertical entrainment was the dominant process controlling mixed layer CO2, with fluxes that were 1.8 to 2.2 times greater than the gas exchange fluxes during the first two drifter deployments, and was 1.7 times greater during the third deployment. In contrast, during the first two deployments the surface mixed layer was always a source of O2 to the atmosphere, and air-sea gas exchange was the dominant process occurring, with fluxes that were 2.0 to 4.1 times greater than the vertical entrainment flux. During the third deployment O2 was near saturation the entire deployment and was a small source of O2 to the atmosphere. Net community production (NCP) was low during this study, with mean fluxes of 3.2 to 6.4 mmol C m−2 d−1 during the first deployment and nondetectable (within uncertainty) in the third. During the second deployment the NCP was not separable from lateral advection. Overall, this study indicates that in the early fall the area is a significant sink for atmospheric CO2

Subseasonal hydrometeorological ensemble predictions in small- and medium-sized mountainous catchments: benefits of the NWP approach

Traditional ensemble streamflow prediction (ESP) systems are known to provide a valuable baseline to predict streamflows at the subseasonal to seasonal timescale. They exploit a combination of initial conditions and past meteorological observations, and can often provide useful forecasts of the expected streamflow in the upcoming month. In recent years, numerical weather prediction (NWP) models for subseasonal to seasonal timescales have made large progress and can provide added value to such a traditional ESP approach. Before using such meteorological predictions two major problems need to be solved: the correction of biases, and downscaling to increase the spatial resolution. Various methods exist to overcome these problems, but the potential of using NWP information and the relative merit of the different statistical and modelling steps remain open. To address this question, we compare a traditional ESP system with a subseasonal hydrometeorological ensemble prediction system in three alpine catchments with varying hydroclimatic conditions and areas between 80 and 1700&thinsp;km2. Uncorrected and corrected (pre-processed) temperature and precipitation reforecasts from the ECMWF subseasonal NWP model are used to run the hydrological simulations and the performance of the resulting streamflow predictions is assessed with commonly used verification scores characterizing different aspects of the forecasts (ensemble mean and spread). Our results indicate that the NWP-based approach can provide superior prediction to the ESP approach, especially at shorter lead times. In snow-dominated catchments the pre-processing of the meteorological input further improves the performance of the predictions. This is most pronounced in late winter and spring when snow melting occurs. Moreover, our results highlight the importance of snow-related processes for subseasonal streamflow predictions in mountainous regions.</p