Combining Ring Width, Density and Stable Carbon Isotope Proxies to Enhance the Climate Signal in Tree-Rings: An Example from the Southern French Alps

At present the most powerful tree-ring based climate reconstructions use high numbers of growth proxy series (ring width and density) to produce spatially smoothed estimates, such as average Northern Hemisphere summer temperatures. These single parameter reconstructions might be supplemented with regional climate reconstructions capable of capturing variability in more than one climate variable without lower replication compromising statistical quality, if multiple tree ring proxies were used. Pinus sylvestris and Pinus uncinata latewood density, width and δ¹³C series are presented from two sites in the French subalpine zone, east of Briançon. Where two proxies have the same dominant climate control their combination enhances that signal. Where proxies differ in dominant controlling climate variable, combining series allows access to bi-variable calibrations. Using this approach, multi-proxy reconstructions of both temperature and precipitation would better reflect complex synoptic variability in climate on spatially useful scales.     

Linking censuses through time: problems and solutions

This paper reviews the difficulties encountered when attempting to study social change by comparing data from successive censuses, and describes a system designed to provide integrated online access to data from the 1971, 1981 and 1991 Censuses in Great Britain at http://census.ac.uk/cdu/lct/.     

Configuring floating production networks: A case study of a new offshore wind technology across two oil and gas economies

ABSTRACT

The authors employ the global production network (GPN) approach to analyse the development of the renewable energy sector. Through a case study of the development of a Hywind floating offshore wind project (Hywind) across two oil and gas economies, namely Norway and Scotland, the paper sheds light on the key drivers and role of core GPN actors. Methodologically, the authors investigate the process from both ‘inside-out’ and ‘outside-in’ perspectives, referring to the efforts of firms expanding into overseas markets and the efforts of host countries to attract investment from outside their territories. The analysis shows how the configuration of extractive production networks is shaped by the interactions between the network development practices of firms and the market development strategies of host states. The authors conclude that the distinct materiality of floating wind power technology shapes the territorial configuration of the production network by enabling its spatial extension across a range of locations. By contrast, existing research on other extractive sectors has emphasized the spatially constraining effects of materiality (Bridge 2008).     

Assessing optical earth observation systems for mapping and monitoring temporary ponds in arid areas

Remote sensing methods for locating and monitoring temporary ponds over large areas in arid lands were tested on a study site in Northern Senegal. Three main results are presented, validated with field data and intended to highlight different spectral, spatial and temporal characteristics of the methods: (1) Among several water indices tested, two Middle Infrared-based indices (MNDWI—Modified Normalized Difference Water Index and NDWI₁—Normalized Difference Water Index) are found to be most efficient; (2) an objective method is given prescribing the necessary sensor spatial resolution in terms of minimal detected pond area; and (3) the potential of multi-temporal MODIS imagery for tracking the filling phases of small ponds is illustrated. These results should assist in epidemiological studies of vector-borne diseases that develop around these ponds, but also more generally for land and water management and preservation of threatened ecosystems in arid areas.     

Book review of Mechanics of Bio-Sediment Transport,Hongwei Fang,Lei Huang,Huiming Zhao,Wei Cheng,Yishan Chen,Mehdi Fazeli,Qianqin Shang (Eds.), Springer-Verlag,Berlin Heidelberg (2020)

Sediment transport is a classical subject in hydraulic engineering,and relevant to fluvial processes,flood control,reservoir operation,and river management.Mode...     

Degree of rock surface weathering as an indicator of ice-sheet thickness along an east—west transect across southern Norway

Rock surface weathering, as reflected by rock surface hardness and roughness, was measured at six mountains along an east-west transect across southern Norway. At most sites the results show significant differences in rock surface weathering across the autochthonous blockfield boundary, suggesting that the areas above the boundary have been exposed to subaerial weathering for a considerably longer time span that the areas below. The results are interpreted as reflecting the surface profile of an asymmetric, west-centred, low-gradient ice sheet.