The effects of sunspots on solar irradiance

Sunspots have an obvious direct effect upon the visible radiant energy falling upon the Earth. We show how to estimate this effect and compare it quantitatively with recent observations of the solar total irradiance (Willson et al., 1981). The sunspots explain about half of the total observed variance of one-day averages. Since the sunspot effect on irradiance produces an asymmetry of the solar radiation, rather than (necessarily) a variation of the total luminosity, we have also estimated the sunspot population on the invisible hemisphere. This extrapolation allows us to estimate the true luminosity deficit produced by sunspots, in a manner that tends toward the correct long-term average value. We find no evidence for instantaneous global re-emission to compensate for the sunspot flux deficit.     

The Vale de Abrutiga uranium phosphates mine, central Portugal

A brief summary about the composition and origins of the U deposit is present. The mineralization is composed by secondary uranium phosphates (saleeite and meta-saleeite). The precipitation was probably the main responsible factor for U retention within the quartz veins leading to the uranium phosphate mineralization of Vale de Abrutiga.     

Interactions of an urban heat island and sea-breeze circulations during winter over the metropolitan area of São Paulo,Brazil

The Town Energy Budget (TEB) model, a detailed urban parameterisation using a generalised canyon geometry, coupled with the Regional Atmospheric Modelling System (RAMS) is used to simulate the wintertime local circulation in the megacity environment of the metropolitan area of Sao Paulo (MASP) in Brazil. Model simulations are performed using actual topography and land-use fields. Comparison with a simple urban parameterisation based on the LEAF-2 scheme is also shown. Validation is based on comparison between model simulations and observations. Sensitivity tests with TEB reveal an important interaction between the sea breeze and the MASP heat island circulation. Even though topography is known to play an important role in the MASP region’s weather, in these tests the simulations were performed without topography in order to unambiguously identify the interaction between the two local circulations. The urban heat island (UHI) forms a strong convergence zone in the centre of the city and thereby accelerates the sea-breeze front toward the centre of the city. The presence of the urban region increases the sea-breeze front propagation mean speed by about 0.32 m s⁻¹ when compared with the situation of no city. After its arrival in the urban region, the sea-breeze front stalls over the centre of the city for about 2 h. Subsequently, the sea breeze progresses beyond the city when the heat island dissipates. Thereafter, the sea breeze propagates beyond the urban area at a decelerated rate compared to a simulation without an UHI.     

Hydrofluoric Acid‐Free Digestion of Geological Samples for the Quantification of Rare Earth Elements by Inductively Coupled Plasma‐Optical Emission Spectrometry

Rare earth elements (REEs) are very important to technological development as well as to geochemical and environmental studies. In this work, hydrofluoric acid (HF) was replaced by condensed phosphoric acid (CPA) in the digestion of geological samples, and the quantification of REEs was performed by inductively coupled plasma‐optical emission spectrometry (ICP‐OES). Six international reference materials (RMs), named DC86318, CGL 111, CGL 124, CGL 126, OKA‐2 and COQ‐1 and three Brazilian ore samples, named Araxá, Catalão and Pitinga were analysed. Only zircon and xenotime, which are potential REE‐bearing minerals, were not completely dissolved. Nevertheless, no REE associated with zircon was detected. The investigated digestion method presented many advantages: It was relatively fast (3 h), avoided fluoride precipitation, it was less hazardous because handling diluted H₃PO₄ is safer than HF, NH₄F or NH₄HF₂ aqueous solutions, it preserved the quartz fittings of the measurement equipment and the final solution contained lower levels of total dissolved solids than those produced by the fusion method.     

Assessing the control exerted by soil mineralogy in the fixation of potentially harmful elements in the urban soils of Lisbon,Portugal

The main purposes of this study are the textural, chemical and mineralogical characterization of the urban soils of Lisbon and the identification of probable relations between the several soil properties. The results are used to infer which soil properties control the superficial dispersion of potential harmful elements to human health. Soil sampling was carried out in 51 selected sites all through the city, under the criterion that such sites should be spaces usually frequented by children. The concentrations of 42 elements in the >2 mm soil size fraction were determined at a commercial laboratory in Canada (ActLabs, LTD), by ICP-MS/ICP-OES after an acid digestion with aqua regia. The soil mineralogy was determined by X-ray diffraction in the <2 and <62 μm size fractions. The results indicate that the urban soils have mainly a sandy texture and a main mineralogical assemblage of quartz, K-feldspar, plagioclase and calcite. In terms of clay minerals, smectite, illite and kaolinite are the main clays in the soil. Smectite and illite show a dichotomy in their distribution, with the smectites prevailing in the soils of the volcanic complex of Lisbon, which are classified as being residual, and illite prevailing in the remaining soils, which are considered mainly as man-made soils. Smectite seems to exert an important role in the fixation of Ni and Cr. The results of the geochemical study show that Ni and Cr have concentrations above the soil guideline value established to the UK and pose a probable risk to human health.     

Towards a spatial data infrastructure for technological disasters: an approach for the road transportation of hazardous materials

Spatial data have been used for the environmental monitoring of the consequences of accidents that involve the transportation of hazardous chemical products. This spatial data infrastructure (SDI), which was created for the sharing and use of spatial data, is limited by the absence of policies to support its establishment. The main objective of this study was to explore the use of social network analysis (SNA) as a tool to identify spatial data sharing between organizations involved in the management of accidents related to road transport of hazardous materials (RTHM). In addition, to discuss the existing policies and institutional agreements, and to initiate a conceptual SDI framework for RTHM sector. In this context, the institutions that are involved with RTHM were identified and information concerning their interest in the use and sharing of spatial data via a SDI was collected through interviews and consolidated. The interviews were at 39 institutions with representative employees. The interview data were tabulated and entered into the UCINET software (2000 version) to calculate metrics of centrality. From the SNA, the flow of data among the participating institutions was identified through the visual representation of the spatial data sharing and use networks. Subsequently, the existing institutional agreements for spatial data sharing were analyzed and discussed. The compiled results enabled the proposal of a conceptual SDI framework to support the management of disasters involving RTHM, based on the application of SNA theory, and the development of a methodology that supports the analysis of interactions among the various actors of an SDI. The purpose is to facilitate the formulation of policies for the sharing of spatial data for decision-making and preventive disaster management. The results indicate that the 39 institutions share spatial data, but this sharing is not always predetermined by formal agreements. Furthermore, there is a strong demand, by the institutions involved in the management of RTHM accidents, regarding legal mechanisms governing the sharing of data for the purpose of producing maps that help to describe actions of preparedness, prevention, management and immediate relief involving RTHM incidents. Finally, it was possible to propose a conceptual framework with data that is considered essential for creating an SDI for RTHM.     

Land Changes Fostering Atlantic Forest Transition in Brazil: Evidence from the Paraíba Valley

The Atlantic Forest biome has only 13 percent of its pristine vegetation cover left. This article analyzes the consequences of land changes on forest cover in the Paraíba Valley, São Paulo state, Brazil, from 1985 to 2011. Multitemporal satellite image classifications were carried out to map eight land use and land cover classes. The forest cover increased from 2,696 km² in 1985 to 4,704 km² in 2011, mostly over areas of degraded pastures. The highest rates of afforestation were observed within protected areas around eucalyptus plantations. On the other hand, deforestation processes were concentrated on areas covered by secondary forests. Socioeconomic changes taking place in particular Brazilian settings, such as industrialization and agricultural modernization, allied to the Paraíba Valley's natural biophysical constraints for agricultural production, have led the region to experience a remarkable case of forest transition.     

The relationship between South Atlantic SST and SACZ intensity and positioning

This study explores the ocean–atmosphere interaction in the formation and dynamics of the South Atlantic Convergence Zone (SACZ), through the analysis of the heat sources estimated through the outgoing longwave radiation. The results obtained with this study show that the coupled variability between SACZ and the South Atlantic Ocean indicates that in northern positioned SACZ cases (over Southeastern Brazil), westerly anomalies are verified in the low level continental tropical circulation, consistent with the active phase of the South America Monsoon System (SAMS). In these cases, cold anomalies in the subtropical Atlantic Ocean cause an increase in the continent–ocean temperature gradient, favoring an easterly flow in this region, and blocking the SACZ at a northerly position. Easterly anomalies in the tropical continent were verified in the low level circulation in southern positioned cases (over Southern Brazil), consistent with the SAMS break phase. The SST anomaly patterns indicate cold anomalies in the tropics and warm anomalies in the subtropics, which do not favor the development of an easterly flow at low levels over the western tropical Atlantic. In these cases, two situations may occur: the strengthening of the Low Level Jet (LLJ), which prevails in the eastern subtropical South America and convergence with the South Atlantic Subtropical High at its southern position; or the atmospheric unstable conditions caused by ocean warm SST anomalies (in this case the LLJ may be weaker than its climatological intensity).     

Metal distribution in sediment cores from São Paulo State Coast, Brazil

Ten sediment core samples with lengths ranging from 35 to 100 cm were collected in the Baixada Santista region and analyzed to determine As, Br, Co, Cr, Cs, Fe, Rb, Sb, Ta, Th, U, Zn and rare earths (Sc, Ce, Eu, La, Lu, Nd, Sm, Tb and Yb) level concentrations using instrumental neutron activation analysis (INAA). The studied region is located in the southeastern coast of São Paulo State and is comprised of a densely urbanized area, the largest industrial complex of the country, with a predominance of petrochemical and fertilizer plants. It is also home to Brazil’s most important and busiest port. The conclusions found that the As, La, Sm, Ne, Ce, Eu, Hf, Ta, Th, and U elements have a high background level in the region and that Fe and Zn were the main indicators of anthropogenic contribution in the sediments.