The impact of Arctic sea ice on the Arctic energy budget and on the climate of the Northern mid-latitudes

The atmospheric general circulation model EC-EARTH-IFS has been applied to investigate the influence of both a reduced and a removed Arctic sea ice cover on the Arctic energy budget and on the climate of the Northern mid-latitudes. Three 40-year simulations driven by original and modified ERA-40 sea surface temperatures and sea ice concentrations have been performed at T255L62 resolution, corresponding to 79 km horizontal resolution. Simulated changes between sensitivity and reference experiments are most pronounced over the Arctic itself where the reduced or removed sea ice leads to strongly increased upward heat and longwave radiation fluxes and precipitation in winter. In summer, the most pronounced change is the stronger absorption of shortwave radiation which is enhanced by optically thinner clouds. Averaged over the year and over the area north of 70° N, the negative energy imbalance at the top of the atmosphere decreases by about 10 W/m2 in both sensitivity experiments. The energy transport across 70° N is reduced. Changes are not restricted to the Arctic. Less extreme cold events and less precipitation are simulated in sub-Arctic and Northern mid-latitude regions in winter

Der Wasser- und Energiehaushalt der arktischen Atmosphäre

Die arktische Atmosphäre spielt als eine große Energiesenke im globalen Klimasystem eine entscheidende Rolle und beeinflusst maßgeblich das Klima der mittleren Breiten. Um die klimatologisch mittleren Wasser- und Energietransporte &uumlber die unteren, seitlichen und oberen Ränder der arktischen Atmosphäre nördlich von 70°N in Abhängigkeit von der Jahreszeit zu berechnen, wird das regionale Klimamodell REMO nach umfangreicher Weiterentwicklung f&uumlr Studien in der Arktis verwendet. Ferner werden die Einfl&uumlsse der Nordatlantischen Oszillation und der Meereisverteilung auf den Wasser- und Energiehaushalt der arktischen Atmosphäre untersucht. Die Nordatlantische Oszillation hat einen deutlichen Einfluss insbesondere auf den Wasserhaushalt der arktischen Atmosphäre. Es wird gezeigt, dass eine Änderung der Eisverteilung in der Arktis eine Änderung der großskaligen Zirkulation und damit eine Änderung des Klimas nicht nur in der Arktis, sondern auch in den mittleren Breiten bewirken kann

Extended-spectrum β-lactamase-producing and AmpC-producing Escherichia coli from livestock and companion animals, and their putative impact on public health: a global perspective

AbstractThe possible zoonotic spread of antimicrobial-resistant bacteria is controversial. This review discusses global molecular epidemiological data combining both analyses of the chromosomal background, using multilocus sequence typing (MLST), and analyses of plasmid (episomal) extended-spectrum β-lactamase (ESBL)/AmpC genes in Escherichia coli present in humans and animals. For consideration of major epidemiological differences, animals were separated into livestock and companion animals. MLST revealed the existence of ESBL-producing isolates thoughout the E. coli population, with no obvious association with any ancestral EcoR group. A similar distribution of major ESBL/AmpC types was apparent only in human isolates, regardless of their geographical origin from Europe, Asia, or the Americas, whereas in animals this varied extensively between animal groups and across different geographical areas. In contrast to the diversity of episomal ESBL/AmpC types, isolates from human and animals mainly shared identical sequence types (STs), suggesting transmission or parallel micro-evolution. In conclusion, the opinion that animal ESBL-producing E. coli is a major source of human infections is oversimplified, and neglects a highly complex scenario

The impact of the climate change on discharge of Suir River Catchment (Ireland) under different climate scenarios

International audienceThe impact of climate change on local discharge variability is investigated in the Suir River Catchment which is located in the south-east of Ireland. In this paper, the Rossby Centre Regional Atmospheric Model (RCA) is driven by different global climate data sets. For the past climate (1961?2000), the model is driven by ECMWF reanalysis (ERA-40) data as well as by the output of the general circulation models (GCM's) ECHAM4 and ECHAM5. For the future simulation (2021?2060), the model is driven by two GCM scenarios: ECHAM4_B2 and ECHAM5_A2. To investigate the influence of changed future climate on local discharge, the precipitation of the model output is used as input for the HBV hydrological model. The calibration and validation results of our ERA-40 driven present day simulation shows that the HBV model can reproduce the discharge fairly well, except the extreme discharge is systematically underestimated by about 15?20%. Altogether the application of a high resolution regional climate model in connection with a conceptual hydrological model is capable of capturing the local variability of river discharge for present-day climate using boundary values assimilated with observations such as ERA-40 data. However, using GCM data to drive RCA and HBV suggests, that there is still large uncertainty connected with the GCM formulation: For present day climate the validation of the ECHAM4 and ECHAM5 driven simulations indicates stronger discharge compared to the observations due to overprediction of precipitation, especially for the ECHAM5 driven simulation in the summer season. Whereas according to the ECHAM4_B2 scenario the discharge generally increases ? most pronounced in the wet winter time, there are only slight increases in winter and considerable decreases in summer according to the ECHAM5_A2 scenario. This also leads to a different behaviour in the evolution of return levels of extreme discharge events: Strong increases according to the ECHAM4_B2 scenario and slight decreases according to the ECHAM5_A2 scenario

Memorandum on a new financial architecture and new regulations

The financial crisis is global and is deeply rooted in a decade-long misuse of the financial market for rent-seeking. The financial industry has largely abandoned its role as a service industry, supposedly charging reasonable fees for the services of spreading risk and allocating capital and credit. Instead it provides a market for corporate control –mergers and acquisitions– and a casino for betting on or hedging practically any kind of risk –the derivatives market–.Publisher's Versio

Author Correction: Analysis of mutations in pncA reveals non-overlapping patterns among various lineages of Mycobacterium tuberculosis.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper

Sustainable Growth: Modelling, Issues and Policies

This document is a literature review of sustainable growth. Because there are many definitions of sustainable growth, we use the following one that is very common in economics. Economic growth is 'sustainable', if it meets the needs of the present generations without compromising the ability of future generations to meet their own needs. This concerns both the availability of resources for future generations and the environmental impacts of current decisions on future activities. Section I, we consider issues and policy measures related to the resource problem. We introduce dynamic models in which exhaustible resources are used in production and apply them to several cases: an open economy, a backstop technology and the relationship of climate and economic growth. We also examine a transition of dirty to clean technology and the consequences of this to public finance and intergenerational equity. In Section II, we consider macroeconomic performance with natural resources: origins and effects of resource abundance, patterns of development for world prices, resource depletion, peak production, "Dutch disease" and external debt. If economic growth affects environment, then the abatement of environmental damages must be included into the discussion of sustainable economic growth. In Section III, we present resource extraction and the environmental impacts of economic activities in the context of multiple decision makers. This introduces strategic interactions of agents, e.g. firms, households and nations. We consider collusion as well as Cournot, Bertrand games and discuss on diverse micro and macro policies that consider incentive compatibility. In the Appendix, we introduce a finite horizon procedure called Nonlinear Model Predictive Control (NMC) by which the models presented in this survey can be numerically solved

Exploring the ocean mesoscale at reduced computational cost with FESOM 2.5: efficient modeling strategies applied to the Southern Ocean

Modeled projections of climate change typically do not include a well-resolved ocean mesoscale due to the high computational cost of running high-resolution models for long time periods. This challenge is addressed using efficiency-maximizing modeling strategies applied to 3 km simulations of the Southern Ocean in past, present, and future climates. The model setup exploits reduced-resolution spin-up and transient simulations to initialize a regionally refined, high-resolution ocean model during short time periods. The results are compared with satellite altimetry data and more traditional eddy-present simulations and evaluated based on their ability to reproduce observed mesoscale activity and to reveal a response to climate change distinct from natural variability. The high-resolution simulations reproduce the observed magnitude of Southern Ocean eddy kinetic energy (EKE) well, but differences remain in local magnitudes and the distribution of EKE. The coarser, eddy-permitting ensemble simulates a similar pattern of EKE but underrepresents observed levels by 55 %. At approximately 1 ∘C of warming, the high-resolution simulations produce no change in overall EKE, in contrast to full ensemble agreement regarding EKE rise within the eddy-permitting simulations. At approximately 4 ∘C of warming, both datasets produce consistent levels of EKE rise in relative terms, although not absolute magnitudes, as well as an increase in EKE variability. Simulated EKE rise is concentrated where flow interacts with bathymetric features in regions already known to be eddy-rich. Regional EKE change in the high-resolution simulations is consistent with changes seen in at least four of five eddy-permitting ensemble members at 1 ∘C of warming and all ensemble members at 4 ∘C. However, substantial noise would make these changes difficult to distinguish from natural variability without an ensemble.</p

Determination of the Defining Boundary in Nuclear Magnetic Resonance Diffusion Experiments

While nuclear magnetic resonance diffusion experiments are widely used to resolve structures confining the diffusion process, it has been elusive whether they can exactly reveal these structures. This question is closely related to X-ray scattering and to Kac's "hear the drum" problem. Although the shape of the drum is not "hearable", we show that the confining boundary of closed pores can indeed be detected using modified Stejskal-Tanner magnetic field gradients that preserve the phase information and enable imaging of the average pore in a porous medium with a largely increased signal-to-noise ratio.Comment: 13 pages, 2 figure