A conceptual framework for multi-regional climate change assessments for international market systems with long-term investments

A conceptual framework for climate change assessments of international market systems that involve long-term investments is proposed. The framework is a hybrid of dynamic and static modeling. Dynamic modeling is used for those system components for which temporally continuous modeling is possible, while fixed time slices are used for other system components where it can be assumed that underlying assumptions are held constant within the time slices but allowed to vary between slices. An important component of the framework is the assessment of the “metauncertainty” arising from the structural uncertainties of a linked sequence of climate, production, trade and decision-making models. The impetus for proposing the framework is the paucity of industry-wide assessments for market systems with multiple production regions and long-term capital investments that are vulnerable to climate variations and change, especially climate extremes. The proposed framework is pragmatic, eschewing the ideal for the tractable. Even so, numerous implementation challenges are expected, which are illustrated using an example industry. The conceptual framework is offered as a starting point for further discussions of strategies and approaches for climate change impact, vulnerability and adaptation assessments for international market systems.     

Modeling the photosynthetically active radiation in South West Amazonia under all sky conditions

Accurate estimates of photosynthetically active radiation (PAR) are critical for the development of realistic models of plant productivity. However, in many areas such as the vast Amazon region of South America, there have been few empirical studies of PAR. Here, we analyzed the relationship between PAR and broadband solar irradiance (R _s) and formulated models to estimate PAR in two experimental sites (pasture and forest) in the Brazilian Amazon. Three different models of increasing complexity were developed based on information from R _s (model 1), R _s and clearness index (k _t; model 2), and R _s, k _t, and water vapor pressure (model 3). Estimates of PAR were generated for each season and for the entire year. All models had very high determination coefficients and indices of agreement for both pasture and forest sites. This strongly supports the use of R _s and k _t to produce robust estimates of PAR. The results obtained by annual models were close than that found by seasonal models, demonstrating that a single annual model is able to estimate PAR, albeit with lower accuracy.     

The nature, use and problems of historical archives for the temporal occurrence of landslides, with specific reference to the south coast of Britain, Ventnor, Isle of Wight

The purpose of this paper is to describe and evaluate the nature of the European historical archives which are suitable for the assessment of the temporal occurrence and forecasting within landslides studies, using the British south coast as an example. The paper is based upon the British contribution to the Environment programme EPOCH, 1991–1993.A primary requirement of a research programme on process occurrence is to determine the event frequencies on as many time and space scales as possible. Thus, the analysis of archives is, potentially, an essential preliminary to the study of the temporal occurrence of landslide events. The range of such data sources extends from isolated, fortuitously dated sites from the Quaternary assemblage, through inferred event impacts using dendrochronology or lichenometric time series to historical records of causal factors such as rainfall data and more recently, deliberately recorded packages of cumulative or continuous data.Most countries have extensive historical sources which may be of considerable value in establishing the characteristics of geomorphological processes. These include narrative in literature, prints and other artwork, terrestrial and aerial photographs, remote sensing series, newspapers, incidental statements and scientific journals and reports.These are numerous difficulties in accessing, extracting, organising, databasing and analysing such data because they are not usually collated for scientific use. Problems involve such incalculable errors as: the experience, training and conscientiousness of the observer; the editing and recording process; judging the validity of the data used and the haphazard nature of recorded events in time and space.Despite these difficulties, such data do yield a record which adds to the representative temporal sample as a level above some threshold reporting position. It therefore has potential for specific statistical analysis. An example of a reasonable temporal landslide record is the data base of the Ventnor complex on the Isle of Wight initially established in 1991 by Geomorphological Services Limited (GSL), now of Rendel Geotechnics, and supplemented by the collections of the first author. The record displays an increase in landslide events over the present century, due probably to increasing technology and awareness of hazard and the development of process geomorphology. However, the landslide record was subsequently correlated with the Ventnor precipitation series. This indicated that wet year sequences usually gave rise to significant landslide events. The increasing variability and number of rainfall events predicted by various climatic units, e.g. the Hadley Centre, may therefore indicate a fundamental increase in landslide events in the future.     

Realistic modelling of shelf-estuary regions

A very high-resolution modelling configuration was created for the estuary of Baía de Todos os Santos – BTS, Brazil (300 to 400 m), and adjacent coastal waters (600 to 1200 m). The adoption of a multi-corner domain approach allowed the variable spatial resolution required to resolve the shelf, the bay and their interactions. Seven years were simulated using realistic oceanic, atmospheric and riverine forcing. Model validation was done against observations showing the model skill to reproduce the thermohaline field, the tidal currents, as well as the variability of the free surface at tidal and sub-tidal time scales. The results provide the first representation of the tidal wave propagation along the bay, in terms of maps of amplitudes, phases and ellipses of the barotropic currents for the main tidal constituents. By analysing the residual currents at different depths, in terms of averages over the simulation period, several prominent structures were identified and named: (i) Salvador eddy (up to 0.2 m s⁻¹); (ii) St Antonio current (up to 0.45 m s⁻¹); (iii) Salvador current (up to 0.5 m s⁻¹); (iv) Itaparica eddy (up to 0.2 m s⁻¹); (v) Ilha dos Frades southern eddy (up to 0.1 m s⁻¹); and (vi) Ilha dos Frades northern eddy (up to 0.2 m s⁻¹). The model set-up proved to be highly efficient and robust simulating the BTS shelf-estuary region and such an approach may be suitable to other estuarine systems.

     

Rubber tapper identities: Political-economic dynamics,livelihood shifts,and environmental implications in a changing Amazon

Rubber tappers promoted extractive reserves as a sustainable alternative to forest destruction in the Brazilian Amazon. However, the significance of rubber tapping itself has declined since the creation of extractive reserves, which raises questions about the contemporary cultural content of the rubber tapper identity. This paper therefore evaluates rubber tapper identity, using the case of the Chico Mendes Extractive Reserve (CMER) in Acre, Brazil. We first draw on household survey data from the CMER to construct a statistical model of who self-identifies as a rubber tapper. The model shows that socio-economic background, household assets, institutional context, and knowledge of the CMER’s management plan are relevant to understanding rubber tapper self-identification, but not resource management practices, including rubber tapping itself. We therefore pursue qualitative analysis of key informant interviews to better apprehend contemporary understandings of the “rubber tapper” identity, particularly in light of recent shifts in livelihoods from rubber tapping toward cattle ranching. The qualitative analysis shows that there are now several different foundations for self-identifying as a “rubber tapper,” and that there are disagreements concerning the acceptability of cattle ranching among “rubber tappers.” These findings bear implications for research on the relationship of livelihood-based identities with resource management practices and environmental change, as well as public policies that seek to reconcile regional development with forest conservation.     

Eutrophication and hypoxia in four streams discharging in Guanabara Bay, RJ, Brazil, a case study

Four streams in the city of São Gonçalo, were sampled to evaluate their potential as sources of nutrients to Guanabara Bay aiming to contribute with the government program to decrease the levels of pollution in this area. Imbuaçu, Guaxindiba, Marimbondo and Brandoas streams were sampled in 2007, 2008 and 2009. The streams revealed to be hipereutrophic with severe limitation of primary production by nitrogen, as shown by the N/P molar ratio. Phosphate levels were abnormally high varying between 4.35 and 130.82 μM, whereas nitrate and nitrite ranged from 0.06 to 54.05 μM and from 0.28 to 19.23 μM, respectively. The streams also presented severe hypoxia and anoxia, with oxygen values varying from non-detected to 3.72 ml l⁻¹. Heavy loads of particulate suspended material were recorded in the studied streams, ranging between 6.00 and 400.00 mg l⁻¹. The streams were considered inexorable sources of nutrients, enhancing the severe eutrophication process in Guanabara Bay.     

Elastoplastic constitutive modelling of soil–structure interfaces under monotonic and cyclic loading

This paper is dedicated to the non-linear numerical modelling of the soil–structure interface. Thus, in a first part, after the presentation of the constitutive model, the soil–structure interface interaction is treated in terms of direct shear test simulations. A strategy for the interface model parameters’ identification is also presented. This strategy is linked to the similitude of soil–structure interface behavior and the soil behavior, regarding the interface surface roughness. In a second part, the performance of the numerical simulations are verified numerically against published results for soil–structure experimental shear tests. Finally, as an application, interface stress paths are studied in axially loaded pile–soil systems and load transfer mechanisms are identified.     

OSIRIS software: the Mask Designer Tool

OSIRIS is a Day One instrument that will be available at the 10m GTC telescope which is being built at La Palma observatory in the Canary Islands. This optical instrument is designed to obtain wide-field narrow-band images using tunable filters and to do low-resolution spectroscopy in both long-slit and multislit modes. For the multislit spectroscopy mode, we have developed a software to assist the observers to design focal plane masks. In this paper we describe the characteristics of this Mask Designer tool. We discuss the main design concepts, the functionality and particular features of the software.     

Gravitational wave background from Population III black hole formation

We study the generation of a stochastic gravitational wave (GW) background produced from a population of core-collapse supernovae, which form black holes in scenarios of structure formation. We obtain, for example, that the formation of a population (Population III) of black holes, in cold dark matter scenarios, could generate a stochastic GW background with a maximum amplitude of   h _BG≃10⁻²⁴  and corresponding closure energy density of  Ω_GW∼10⁻⁷  , in the frequency band   ν _obs≃30–470 Hz  (assuming a maximum efficiency of generation of GWs, namely,   ɛ _GWmax=7×10⁻⁴)  for stars forming at redshifts   z ≃30–10  . We show that it will be possible in the future to detect this isotropic GW background by correlating the signals of a pair of 'advanced' LIGO observatories (LIGO III) at a signal-to-noise ratio of ≃40. We discuss what astrophysical information could be obtained from a positive (or even a negative) detection of such a GW background generated in scenarios such as those studied here. One of them is the possibility of obtaining the initial and final redshifts of the emission period from the observed spectrum of GWs.