Effects of clouds on the surface shortwave radiation at a rural inland mid-latitude site

Seven years (2003–2010) of measured shortwave (SW) irradiances were used to obtain estimates of the 10 min averaged effective cloud optical thickness (ECOT) and of the shortwave cloud radiative effect (CRESW) at the surface in a mid-latitude site (Évora — south of Portugal), and its seasonal variability is presented. The ECOT, obtained using transmittance measurements at 415 nm, was compared with the correspondent MODIS cloud optical thickness (MODIS COT) for non-precipitating water clouds and cloud fractions higher than 0.25. This comparison showed that the ECOT represents well the cloud optical thickness over the study area. The CRESW, determined for two SW broadband ranges (300–1100 nm; 285–2800 nm), was normalized (NCRESW) and related with the obtained ECOT. A logarithmic relation between NCRESW and ECOT was found for both SW ranges, presenting lower dispersion for overcast-sky situations than for partially cloudy-sky situations. The NCRESW efficiency (NCRESW per unit of ECOT) was also related with the ECOT for overcast-sky conditions. The relation found is parameterized by a power law function showing that NCRESW efficiency decreases as the ECOT increases, approaching one for ECOT values higher than about 50.

Avaliação do potencial eólico da zona de Évora - Contribuição para a redução de emissões de CO2

Neste trabalho é analisado o potencial eólico da região de Évora, tendo sido considerados quatro locais: Mitra, Portel, Reguengos e Colégio Verney. Com os dados de potência obtidos, foram escolhidas duas turbinas existentes no mercado, de potências nominais diferentes, para uma análise mais objectiva do real potencial da região. Apurou-se que, com a instalação de três turbinas menores, se obtém praticamente a mesma potência, por um preço consideravelmente inferior. Foi ainda possível verificar-se que a quantidade evitada de C02 para a atmosfera, ao considerar uma turbina de 5000 W (B) ou três 1000 W (A), é semelhante, concluindo-se que, considerando a eficiência, potencial, preço e emissões de co2 evitadas, a instalação de diversas turbinas A é a melhor opção. Este trabalho reveste-se de particular interesse considerando o facto de ser do conhecimento geral que, nas regiões costeiras e montanhosas, o potencial eólico está bastante estudado, ao passo que nas regiões interiores tal não acontece. ABSTRACT: ln this work, we assess the potential wind power in Évora, and four locations have been considered: Mitra, Portel, Reguengos and Évora. Based on the local wind power potential, two kinds of turbines were selected, for a more objective analysis of the region's useful wind power. It was found that the option for three small turbines allows the extraction of the same wind power that is extracted by the bigger turbine and at a considerably lower installation cost. lt was also found that the reduction in co2 emissions to the atmosphere, when considering the cases of one 5000 W (B) turbine and three 1000 W (A) turbines, is similar, therefore was concluded that, given the efficiency, potential, price and reduction of C02 emissions, the installation of several A turbines is the best option. This work is of particular interest because in coastal and mountain areas the wind potential is quite known, while this is not the case of inland areas.

The red swamp crayfish Procambarus clarkii in Europe: Impacts on aquatic ecosystems and human well-being

Procambarus clarkii is currently recorded from 16 European territories. On top of being a vector of crayfish plague, which is responsible for large-scale disappearance of native crayfish species, it causes severe impacts on diverse aquatic ecosystems, due to its rapid life cycle, dispersal capacities, burrowing activities and high population densities. The species has even been recently discovered in caves. This invasive crayfish is a polytrophic keystone species that can exert multiple pressures on ecosystems. Most studies deal with the decline of macrophytes and predation on several species (amphibians, molluscs, and macroinvertebrates), highlighting how this biodiversity loss leads to unbalanced food chains. At a management level, the species is considered as (a) a devastating digger of the water drainage systems in southern and central Europe, (b) an agricultural pest in Mediterranean territories, consuming, for example, young rice plants, and (c) a threat to the restoration of water bodies in north-western Europe. Indeed, among the high-risk species, P. clarkii consistently attained the highest risk rating. Its negative impacts on ecosystem services were evaluated. These may include the loss of provisioning services such as reductions in valued edible native species of regulatory and supporting services, inducing wide changes in ecological communities and increased costs to agriculture and water management. Finally, cultural services may be lost. The species fulfils the criteria of the Article 4(3) of Regulation (EU) No 1143/2014 of the European Parliament (species widely spread in Europe and impossible to eradicate in a cost-effective manner) and has been included in the “Union List”. Particularly, awareness of the ornamental trade through the internet must be reinforced within the European Community and import and trade regulations should be imposed to reduce the availability of this high-risk species.

A segunda vida da Praia dos Espanhóis: dançarinos, pescadores e turistas no sul de Portugal

Abstract: In this text, we deal with proccesses of appropriation of space in the Dam of Póvoa (Portugal) using a dwelling perspective (Ingold 2009) over the territory. The reconversion of innactive spaces in rural areas into leisure-related ones in a quite common practice in contemporary times.The Spaniards beach is one of the local names given by locals to the Dam of Póvoa (Castelo de Vide), in northern Alentejo (Portugal). In the collective memory of the residents, the Dam (built in the 1920’s) is remembered for the many flowers surrounding the area. This Garden-style aesthetics has outlived the initial function of the Dam (to produce electric power). From the 1960’s to the 1980’s, it was also a popular leisure space for Spanish and Portuguese people. It is not a beach, but being inland, it was the closest thing to a beach the residents had. The centrality of this leisure space in the area only decayed after the construction of swimming pools in the nearby towns. Early in the begginning of 21st century a fire destroyed part of the natural floral landscape of the dam. Abandoned for some years, the place has still been appropriated by leisured people in day-trips (for sight-seeing, pic-nics), fishing competitions, caravan soujorns, and, since 2013, in a music and dance festival named Andanças (www.andancas.net). The research that underlies this paper was carried out between 2013 and 2016 by a team of anthropologists. An ethnography of the Dam and its uses, and of the festival and its participants was carried out. In our working-paper we higlight the main research findings achieved. Key-words: Leisure; Landscape; Tourism; Music; Space; Portugal.