Formation pressure testing at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope: Operational summary, history matching, and interpretations

In February 2007, the U.S. Department of Energy, BP Exploration (Alaska), and the U.S. Geological Survey, collected open-hole pressure-response data, as well as gas and water sample collection, in a gas hydrate reservoir (the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well) using Schlumberger's Modular Dynamics Formation Tester (MDT) wireline tool. Four such MDT tests, ranging from six to twelve hours duration, and including a series of flow, sampling, and shut-in periods of various durations, were conducted. Locations for the testing were selected based on NMR and other log data to assure sufficient isolation from reservoir boundaries and zones of excess free water. Test stages in which pressure was reduced sufficiently to mobilize free water in the formation (yet not cause gas hydrate dissociation) produced readily interpretable pressure build-up profiles. Build-ups following larger drawdowns consistently showed gas-hydrate dissociation and gas release (as confirmed by optical fluid analyzer data), as well as progressive dampening of reservoir pressure build-up during sequential tests at a given MDT test station.History matches of one multi-stage, 12-h test (the C2 test) were accomplished using five different reservoir simulators: CMG-STARS, HydrateResSim, MH21-HYDRES, STOMP-HYD, and TOUGH + HYDRATE. Simulations utilized detailed information collected across the reservoir either obtained or determined from geophysical well logs, including thickness (11.3 m, 37 ft.), porosity (35%), hydrate saturation (65%), both mobile and immobile water saturations, intrinsic permeability (1000 mD), pore water salinity (5 ppt), and formation temperature (3.3-3.9 °C). This paper will present the approach and preliminary results of the history-matching efforts, including estimates of initial formation permeability and analyses of the various unique features exhibited by the MDT results.     

Engaging stakeholders in fisheries and marine research

Despite knowledge-brokering being of high interest to public policy, there is a lack of research integrating the knowledge of stakeholders and scientists, principally because public policies remain viewed as top-down controlled. To help European research policies make a positive difference to society, there is a need to better engage stakeholders with the delivery of research and to demonstrate an impact and value that it brings. The pertinent question addressed by this communication is: how can a deeper and more systematic engagement of stakeholders be enabled through European research activities? Enabling stakeholder participation in European research activities requires there to be an incentive for researchers and stakeholders to engage, and the capacity of stakeholders to operate effectively in the research framework. Unsurprisingly, the establishment of communications and cultures conducive to shared problem solving is high priority, as is the need to work towards a governance structure that helps link research with policy outcomes, while at the same time resonating directly with stakeholders. The Regional Advisory Councils could be a strong force in bringing stakeholders knowledge to bear on the scientific issues relevant to management, but their strategy and capacity to mobilise the skills to do so are not yet ready.     

Irish estuaries: Water quality status and monitoring implications under the water framework directive

The status of water quality of Irish estuaries is reviewed; this sheds light on the rationale behind the design of the national monitoring programme. Relative to other EU Member States, Ireland's coastal monitoring programme is relatively young and not as advanced. The monitoring programmes in Ireland pre Water Framework Directive (WFD) were structured on a salinity-based typology, with an emphasis on quantifying the variability of the component elements. Although monitoring is a significant obligation under the WFD, there is little guidance on developing monitoring protocols; Member States are developing ad hoc monitoring programme. The Irish Environmental Protection Agency (EPA), responsible authority, undertook research programmes to assist design and implementation of the WFD. A substantial new national monitoring programme was developed. However, the Irish programme is not optimised; the programme is being refined to include elements not yet covered, notably the biota. New research, by the authors, aims to develop a robust approach towards monitoring integrating data and model results. This paper presents changes in Irish marine water quality monitoring policy and some of the associated research necessary to change policy.     

Projected evolution of circulation types and their temperatures over Central Europe in climate models

The study deals with changes in large-scale atmospheric circulation (represented by circulation types) and associated surface air temperatures as projected in an ensemble of regional climate models (RCMs) from the ENSEMBLES project. We examine changes of circulation type frequencies and means of daily maximum and minimum temperatures within circulation types in individual seasons for two time slices of transient runs under the SRES A1B scenario (2021–2050 and 2071–2100) with respect to the control period (1961–1990). To study the influence of driving data, simulations of the driving general circulation models (GCMs) also are evaluated. We find that all models project changes of atmospheric circulation that are statistically significant for both future time slices. The models tend to project strengthening of the westerly circulation in winter and its weakening in summer. We show that increases of daily maximum and minimum temperatures in all seasons differ for individual circulation types. There are, however, only few features of the projected changes in the future circulation–temperature links that are common among the models, in particular relatively smaller warming for westerly types. Only in winter, projected changes in circulation types tend to contribute to the projected overall warming. This effect is negligible and mostly opposite in the other seasons. We also detect a strong influence of driving data on RCMs’ simulation of atmospheric circulation and temperature changes.     

A tree-ring reconstruction of East Anglian (UK) hydroclimate variability over the last millennium

We present an annually resolved reconstruction of spring-summer precipitation variability in East Anglia, UK (52–53°N, 0–2°E) for the period AD 900–2009. A continuous regional network of 723 living (AD 1590–2009) and historical (AD 781–1790) oak (Quercus sp.) ring-width series has been constructed and shown to display significant sensitivity to precipitation variability during the March-July season. The existence of a coherent common growth signal is demonstrated in oaks growing across East Anglia, containing evidence of near-decadal aperiodic variability in precipitation throughout the last millennium. Positive correlations are established between oak growth and precipitation variability across a large region of northwest Europe, although climate-growth relationships appear time transgressive with correlations significantly weakening during the early twentieth century. Examination of the relationship between oak growth, precipitation, and the North Atlantic Oscillation (NAO), reveals no evidence that the NAO plays any significant role in the control of precipitation or tree growth in this region. Using Regional Curve Standardisation to preserve evidence of low-frequency growth variability in the East Anglian oak chronology, we produce a millennial length reconstruction that is capable of explaining 32–35% of annual-to-decadal regional-scale precipitation variance during 1901–2009. The full length reconstruction indicates statistically significant anomalous dry conditions during AD 900–1100 and circa-1800. An apparent prolonged wetter phase is estimated for the twelfth and thirteen centuries, whilst precipitation fluctuates between wetter and drier phases at near centennial timescales throughout the fourteenth to seventeenth centuries. Above average precipitation reconstructed for the twenty-first century is comparable with that reproduced for the 1600s. The main estimated wet and dry phases reconstructed here appear largely coherent with an independent tree-ring reconstruction for southern-central England.     

Perceived deficiencies in the provision of climate and weather information for tourism: A New Zealand media analysis

Climate and weather are important for tourism and leisure as they impact on destination attractiveness and subsequent visitation. Through an archive analysis of media articles and a content analysis of Regional Tourism Organisation (RTO) websites, this paper explores perceived deficiencies in the currently available climate and weather information for tourists in New Zealand. While media reports focused on concern by many RTOs over the poor regional images generated by inaccurate and poorly presented climate and weather data, the RTO websites were found to contain limited climate and weather information. There is considerable potential for RTOs to improve in this respect.     

Solar Cycle Workshop

The presentations and discussions which took place during the second meeting of the Solar Cycle Workshop are summarized under the headings: sunspot minimum, the extended cycle, the large-scale photospheric motions, the large-scale magnetic fields and the polar reversal, the small-scale fields, global cyclic phenomena and the fundamental processes. The progress achieved so far is assessed and the directions for future observational and theoretical work are suggested.     

The generation of magnetic fields in photospheric layers

Recent observations concerning the growth and decay of photospheric magnetic flux present a challenge to the conventional picture of the photosphere as a passive medium through which flux tubes emerge inertly. Rather, they suggest the possibility that interactions between the magnetic flux and the photospheric velocity fields may give rise to changes in the observed surface flux.In this paper the physics of flux changes are reviewed and the various terms in the hydromagnetic equation which give rise to the growth and decay of magnetic flux are examined. Several kinematic models for field changes are examined and it is shown that new flux loops may be generated by suitable oscillatory velocity fields near the boundaries of existing magnetic structures, thus increasing the gross flux through the photosphere. It is suggested that this mechanism may account for the appearance of moving magnetic features (knots of opposite polarities) at the boundaries of decaying sunspots.Other models are discussed and a tentative explanation of the apparently unbalanced growth of opposite polarities is given in terms of a current-sheet model.     

Generalised eddington approximation for radiative transfer problems in spherically-symmetric moving media

A moment method with three stream division of the radiation field was suggested by Wilson, Wan and Sen (1980) for solving radiative transfer problems in stationary, non-grey extended shells surrounding a central star. Use was made of the generalised Eddington relations as the closure conditions of the moment equations. In the present paper the same method has been utilised to study the radiative transfer problems in a non-grey, expanding gaseous spherical shells surrounding a central star. The transfer equation has been set in comoving frame in spherical geometry. The radiation and material quantities, angles and frequencies have been expressed in comoving frame. The mean intensity, flux and K-integrals have been calculated for extensive atmospheres in the presence of different velocity fields.