Role of Stranded Gas from Central Asia and Russia in Meeting Europe’s Future Import Demand for Gas

Stranded gas is natural gas in discovered fields that is currently not commercially producible for either physical or economic reasons. This study examines stranded gas from Russia and Central Asia and the role it can play in addressing Europe’s growing demand for imported natural gas requiring additional volumes of gas in excess of 130 trillion cubic feet. We find sufficient volumes of stranded gas in fields in the Central Asian state of Turkmenistan in the Amu-Darya Basin and in Russian fields in the West Siberian Basin. The analysis focused on the estimated cost of extraction and delivery to a single market location for various concentrations of gas in stranded gas fields in Central Asia and Russia. At import prices of 10 per million British thermal units (MMBTU), there are sufficient gas resources in stranded fields that can be commercially developed and delivered to the European market. If, however, imported gas prices fall below10 per million British thermal units (MMBTU), there are sufficient gas resources in stranded fields that can be commercially developed and delivered to the European market. If, however, imported gas prices fall below 7 per MMBTU, most of the stranded gas evaluated from West Siberia will not be commercial. The costs of delivering gas from the largest stranded gas fields in Turkmenistan and Azerbaijan were calculated to be greater than 30% below the costs of delivering gas from the largest stranded gas fields in Russia, which are located in the Yamal Peninsula. Central Asian gas producers, particularly those east of the Caspian Sea, have limited market options due to the near monopoly position that Gazprom holds in transporting pipeline gas from east of Europe. This study examines several additional options to supply gas to Europe by reviewing expected delivered costs from North African and Atlantic basin suppliers.     

Theoretical and numerical studies of the Vishniac instability in supernova remnants

Vishniac instability has been theoretically studied in supernova remnants where it is supposed to explain the fragmentation of the interstellar medium. However its role is not fully demonstrated in these astrophysical objects. Conditions and assumptions required for the instability growth are explained in detail in the present paper. In addition the HYDRO-MUSCL hydrodynamic code has been used to simulate this instability in order to compare the numerical growth rate with the Vishniac analytical solution.     

The XMM Cluster Survey: forecasting cosmological and cluster scaling-relation parameter constraints

We forecast the constraints on the values of  σ₈, Ω_m  and cluster scaling-relation parameters which we expect to obtain from the XMM Cluster Survey (XCS). We assume a flat Λ cold dark matter Universe and perform a Monte Carlo Markov Chain analysis of the evolution of the number density of galaxy clusters that takes into account a detailed simulated selection function. Comparing our current observed number of clusters shows good agreement with predictions. We determine the expected degradation of the constraints as a result of self-calibrating the luminosity–temperature relation (with scatter), including temperature measurement errors, and relying on photometric methods for the estimation of galaxy cluster redshifts. We examine the effects of systematic errors in scaling relation and measurement error assumptions. Using only  ( T , z )  self-calibration, we expect to measure Ω_m to ±0.03 (and  Ω_Λ  to the same accuracy assuming flatness), and σ₈ to ±0.05, also constraining the normalization and slope of the luminosity–temperature relation to ±6 and ±13 per cent (at 1σ), respectively, in the process. Self-calibration fails to jointly constrain the scatter and redshift evolution of the luminosity–temperature relation significantly. Additional archival and/or follow-up data will improve on this. We do not expect measurement errors or imperfect knowledge of their distribution to degrade constraints significantly. Scaling-relation systematics can easily lead to cosmological constraints 2σ or more away from the fiducial model. Our treatment is the first exact treatment to this level of detail, and introduces a new 'smoothed ML' (Maximum Likelihood) estimate of expected constraints.     

Annual variation of temperature sensitivity of soil organic carbon decomposition in North peatlands: implications for thermal responses of carbon cycling to global warming

Temperature sensitivities of microbial respiration and dissolved organic carbon (DOC) production were investigated by using a novel method, thermal gradient (2–20°C) temperature bar, in two typical peatlands (bog and fen) in North Wales, UK over 12 months. The study indicated that temperature sensitivity of soil organic carbon decomposition in North peatlands was regulated not only by temperature but soil water content, dry–rewet event and phenologies. Potential decreases of Q₁₀ (CO₂) with increasing soil temperature were confirmed in both peatlands, but Q₁₀ (DOC) increase with increasing soil temperature in both bog and fen sites. These results imply, if other factors such as the so-called CO₂ fertilization effect are simultaneously taken into account, that the feedback of global warming induced CO₂ release from peatlands to climate change may be overestimated in current biogeochemical models. However, global warming might have been nonlinearly accelerating DOC thermal production, and therefore it helps explaining the causes of remarkable increase of DOC in surface water in the Northern Hemisphere during last several decades.     

Internal and forced variability along a section between Greenland and Portugal in the CLIPPER Atlantic model

Numerical models are used to estimate the meridional overturning and transports along the paths of two hydrographic cruises, carried out in 1997 and 2002 from Greenland to Portugal. We have examined the influence of the different paths of the two cruises and found that it could explain 0.4 to 2 Sv of difference in overturning (the precise value is model-dependent). Models show a decrease in the overturning circulation between 1997 and 2002, with different amplitudes. The CLIPPER ATL6 model reproduces well the observed weakening of the overturning in density coordinates between the cruises; in the model, the change is due to the combination of interannual and high-frequency forcing and internal variability associated with eddies and meanders. Examination of the -coordinate overturning reveals model–data discrepancies: the vertical structure in the models does not change as much as the observed one. The East Greenland current variability is mainly wind-forced in the ATL6 model, while fluctuations due to eddies and instabilities explain a large part of the North Atlantic Current variability. The time-residual transport of dense water and heat due to eddy correlations between currents and properties is small across this section, which is normal to the direction of the main current.     

Late Pleistocene glaciations at Lake Donggi Cona,eastern Kunlun Shan (NE Tibet): early maxima and a diminishing trend of glaciation during the last glacial cycle

The Burhan Budai Shan in NE Tibet represents a key location for examining the variable influence of the mid‐latitude westerly and monsoonal circulations on late Quaternary glaciations in this sector of the Tibetan Plateau. Our study investigates the glacial history of mountains near Lake Donggi Cona (35°17′N, 98°33′E) using field mapping in combination with ¹⁰Be surface exposure dating and numerical reconstructions of former glacial equilibrium line altitudes (palaeo‐ELA). A set of 23 new exposure ages, collected from moraines in four glacial valleys, ranges from 45 to 190 ka, indicating ice expansion during the early and middle part of the last glacial cycle, and during the penultimate and possibly an earlier Mid‐Pleistocene glaciation. Ice advances reaching 12–15 km in length occurred at around 190–180 ka (≥MIS 6), between 140–100 ka (late MIS 6/MIS 5), and 90–65 ka (late MIS 5/early MIS 4), with a maximum ELA depression of 400–500 m below the estimated modern snowline. Exposure ages from the valley headwaters further indicate a small glaciation between c. 60–50 ka (late MIS 4/early MIS 3), which was essentially restricted to the cirque areas. Significantly, we find no evidence for any subsequent glaciation in the area during MIS 2 or the Holocene period. These results indicate a diminishing trend of glaciation in the region since at least MIS 4, and corroborate the case of a ‘missing LGM’ in the more interior parts of the northeastern Tibetan Plateau. The emerging pattern suggests that the most favourable conditions for glaciation during the Late Pleistocene correspond to periods of relatively moderate cooling combined with an intermediate or rising East Asian monsoon strength.     

Assessment of the climate preparedness of 30 urban areas in the UK

Cities are increasingly aware of the need to mitigate greenhouse gas emissions and adapt to changes in weather patterns leading to the production of urban climate change plans. The few existing systematic studies of these plans have focused on either adaptation or mitigation issues, and are typically based on surveys completed by city officials rather than analysis of documented evidence. To gain insight into the status of adaptation and mitigation action across the UK, climate change documents from 30 urban areas (representing ~28 % of the UK’s population) were analysed. An Urban Climate Change Preparedness Score, which could be applied to other urban areas outside the UK, has been devised for comparative analysis. This analysis characterizes progress against (i) Assessment, (ii) Planning, (iii) Action, and (iv) Monitoring, for both adaptation and mitigation. The Preparedness Score allows a quantitative comparison of climate change strategies across the urban areas analysed. This methodology can be transferred to other countries and makes an international comparison of urban areas and their climate change adaptation and mitigation plans possible. We found that all areas acknowledge climate change being a threat and that adaptation and mitigation planning and action is required. However, two urban areas did not have official adaptation or mitigation plans. Typically, mitigation activities across all cities were more advanced than adaptation plans. Emissions reduction targets ranged from 10 %–80 % with differing baselines, timeframes and scopes, for defining and meeting these targets. Similar variability was observed across adaptation plans. Several reasons for these differences are considered, but particularly notable is that a combination of incentives and regulation seem to stimulate more comprehensive strategies and action in many urban areas.     

Land use,soil erosion,and sediment yield at Pinto Lake,California: comparison of a simplified USLE model with the lake sediment record

Quantitative interpretation of past land use using palaeolimnological records of sediment yield requires an appropriate soil erosion model. This paper describes the application of a simplified USLE model, comparing the predicted sediment yield with the lake sediment record at Pinto Lake (Central Coast, California). Our principal finding is that simplified USLE prediction, without correction for sediment transport capacity, accurately predicts fine sediment yield. Because the fine component of the soil is delivered far more efficiently than the coarse component, this and related soil erosion models can more readily be applied to the interpretation of palaeolimnological records than to estimation of total sediment yield, for which reliable estimation of hillslope and fluvial sediment storage are more important. The focus on fine sediment also means that the model output is optimal for assessing past ecological impacts of soil erosion on stream water turbidity and particulate transport of pollutants and nutrients.     

Spatial and temporal variability in nutrient concentrations in Liverpool Bay,a temperate latitude region of freshwater influence

This paper presents data for the temporal and spatial distribution of nutrients in Liverpool Bay between 2003 and 2009 and an analysis of inputs of nutrients from the major rivers. The spatial distribution of winter nutrient concentrations are controlled by the region of freshwater influence (ROFI) in Liverpool Bay through the mixing of riverine freshwater and Irish Sea water, with strong linear relationships between nutrient concentration and salinity between December and February. The location of highest spring and summer phytoplankton biomass reflects the nutrient distributions as controlled by the ROFI. Analysis of 7 years of data showed that the seasonal cycle of winter maximum nutrient concentrations in February and drawdown in April/May is a recurrent feature of this location, with the timing of the drawdown varying by several weeks between years. A comparison of observed nutrient concentrations in Liverpool Bay with those predicted from inputs from rivers has been presented. Nutrient concentrations in the rivers flowing into Liverpool Bay were highly variable and there was reasonable agreement between predicted freshwater nutrient concentrations using data from this study and riverine nutrient concentrations weighted on the basis of river flow, although the exact nature of mixing between the rivers could not be determined. Predicted Irish Sea nutrient concentrations in the winter were lower than those reported for the input waters of the North Atlantic, supporting findings from previous work that nitrogen is lost through denitrification in the Irish Sea.