Impact of Lagrangian transport on lower-stratospheric transport timescales in a climate model

We investigate the impact of model trace gas transport schemes on the representation of transport processes in the upper troposphere and lower stratosphere. Towards this end, the Chemical Lagrangian Model of the Stratosphere (CLaMS) was coupled to the ECHAM/MESSy Atmospheric Chemistry (EMAC) model and results from the two transport schemes (Lagrangian critical Lyapunov scheme and flux-form semi-Lagrangian, respectively) were compared. Advection in CLaMS was driven by the EMAC simulation winds, and thereby the only differences in transport between the two sets of results were caused by differences in the transport schemes. To analyze the timescales of large-scale transport, multiple tropical-surface-emitted tracer pulses were performed to calculate age of air spectra, while smaller-scale transport was analyzed via idealized, radioactively decaying tracers emitted in smaller regions (nine grid cells) within the stratosphere. The results show that stratospheric transport barriers are significantly stronger for Lagrangian EMAC-CLaMS transport due to reduced numerical diffusion. In particular, stronger tracer gradients emerge around the polar vortex, at the subtropical jets, and at the edge of the tropical pipe. Inside the polar vortex, the more diffusive EMAC flux-form semi-Lagrangian transport scheme results in a substantially higher amount of air with ages from 0 to 2 years (up to a factor of 5 higher). In the lowermost stratosphere, mean age of air is much smaller in EMAC, owing to stronger diffusive cross-tropopause transport. Conversely, EMAC-CLaMS shows a summertime lowermost stratosphere age inversion – a layer of older air residing below younger air (an “eave”). This pattern is caused by strong poleward transport above the subtropical jet and is entirely blurred by diffusive cross-tropopause transport in EMAC. Potential consequences from the choice of the transport scheme on chemistry–climate and geoengineering simulations are discussed

Corrosion challenges towards a sustainable society

A global transition towards more sustainable, affordable and reliable energy systems is being stimulated by the Paris Agreement and the United Nation's 2030 Agenda for Sustainable Development. This poses a challenge for the corrosion industry, as building climate-resilient energy systems and infrastructures brings with it a long-term direction, so as a result the long-term behaviour of structural materials (mainly metals and alloys) becomes a major prospect. With this in mind "Corrosion Challenges Towards a Sustainable Society" presents a series of cases showing the importance of corrosion protection of metals and alloys in the development of energy production to further understand the science of corrosion, and bring the need for research and the consequences of corrosion into public and political focus. This includes emphasis on the limitation of greenhouse gas emissions, on the lifetime of infrastructures, implants, cultural heritage artefacts, and a variety of other topics

Preliminary Investigation of the Corrosion Behavior of Proprietary Micro-alloyed Steels in Aerated and Deaerated Brine Solutions

The corrosion performance of fairly new generation of micro-alloyed steels was compared in different concentrations of aerated and deaerated brines. Electrochemical polarization, weight loss and surface analyses techniques were employed. The results showed a threshold of corrosion rate at 3.5 wt.% NaCl in both aerated and deaerated solutions. The average corrosion current density for steel B, for example, increased from 1.3 µA cm¯² in 1 wt.% NaCl to 1.5 µA cm¯² in 3.5 wt.% NaCl, but decreased to 1.4 µA cm¯² in 10 wt.% deaerated NaCl solutions. The aerated solutions exhibited an average of over 80% increase in corrosion current density in the respective concentrations when compared with the deaerated solution. These results can be attributed to the effects of dissolved oxygen (DO) which has a maximum solubility in 3.5 wt.% NaCl. DO as a depolarizer and electron acceptor in cathodic reactions accelerates anodic metal dissolution. The difference in carbon content and microstructures occasioned by thermo-mechanical treatment contributed to the witnessed variation in corrosion performance of the steels. Specifically, the results of the various corrosion techniques corroborated each other and showed that the corrosion rate of the micro-alloyed steels can be ranked as CR[Steel A] < CRₓ₆₅ < CR[Steel B] < CR[Steel C]

The Influence of pH on localized corrosion behavior of X65 Carbon Steel in CO2-Saturated Brines

Pitting and localized corrosion of carbon steel is considered to be a complex process influenced by a wide range of parameters such as temperature, bulk solution pH and chloride ion concentration. Solution pH is known to influence corrosion product characteristics and morphology in CO2 and H2S-containing corrosion systems. However, from the perspective of pitting corrosion in CO2-saturated environments, the extent to which bulk pH of solutions and the presence of corrosion products influence localized attack is still not clearly understood. This paper presents an investigation into the role of pH on the characteristics of corrosion product and pitting corrosion behavior of X65 carbon steel in CO2-saturated brine. Pitting corrosion studies were conducted over 168 hours at 50°C in 3.5 wt.% NaCl solutions at different bulk pH (buffered to pH values of 6.6 and 7.5 in some cases) in order to understand and correlate the role of pH on corrosion product morphology, chemistry, initiation and propagation of pits within each distinct environment. Corrosion product composition and morphology are identified through a combination of electrochemical and surface analysis techniques, which include Scanning Electron Microscopy (SEM) and X-Ray Diffraction (XRD). The extent of corrosion damage of the carbon steel is evaluated through the implementation of surface interferometry to study discrete pit geometry; namely, the size, depth and aspect ratio. Results indicate that the process of pit initiation and propagation of carbon steel in CO2 corrosion environment is different depending upon bulk solution pH. At low pH (pH values starting at 3.8), pitting initiates faster and propagates steadily along with significant uniform corrosion due to the formation of ‘amorphous’ form of FeCO3. At higher pH, uniform corrosion is significant, while pitting initiates with increasing protection from crystalline FeCO3. At a pH value of 7.5, pitting corrosion initiation occurs after and/or during pseudo-passivation is achieved due to the formation of a ‘protective and pseudo-passivating’ FeCO3 film

Discrete Choice Experiment data - Experiment 1

Local discrete choice experiment on WTA for wind energy externalitie

Discrete Choice Experiment data - Experiment 2

Discrete choice experiment data on wind energy preferences from a national representive sample of the Norwegian population. Fielded in March 2022 using TNS Kantar&apos;s high-quality panel data.THIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV

Discrete Choice Experiment data - Experiment 1

Local discrete choice experiment on WTA for wind energy externalitiesTHIS DATASET IS ARCHIVED AT DANS/EASY, BUT NOT ACCESSIBLE HERE. TO VIEW A LIST OF FILES AND ACCESS THE FILES IN THIS DATASET CLICK ON THE DOI-LINK ABOV