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The 2020 biomass burning season in Brazil was marked by an atypical amount of fire across the Pantanal biome, which led to high levels of smoke within the biome and downwind areas. The present study analyzes fire counts and smoke over Pantanal in 2020, comparing this particular year's data with those from the previous 17 years (2003–2019). Taking as reference the most-polluted years in this period, the regional smoke plume and its impact on surface solar radiation were also evaluated. In 2020, the regional smoke plume core covered an area of ∼ 2.6×106 km2 at the peak of the burning season, an area well above that of the previous 6 years but smaller than areas observed in a more remote past, as in 2007 and 2010 (> 5.0×106 km2). The smoke loading was lower (mean aerosol optical depth, AOD, of 550 nm ; ∼ 0.7) than that of 2007 and 2010 (mean AOD 550 nm ; ∼ 1.0). The plume radiation absorption efficiency, when compared with the previous year's plumes, did not present significant differences. Regarding the Pantanal burning season, it revealed some atypical features. Fire counts were up to 3.0 times higher than for the years from 2003 to 2019. Smoke loading over Pantanal, which is typically a fraction of that over Amazonia, was higher in 2020 than that over Amazonia, an indication that local smoke surpassed the smoke advection from upwind regions. The observed intraseasonal variability in smoke over Pantanal revealed to be largely driven by the nature of the burned areas in the biome. From September on, there was a significant increase in fire count in conservation and indigenous areas, where higher biomass density is present, which would explain the larger smoke plumes over Pantanal, even during October when the fire count was reduced. In October, the biome was covered by a thick smoke layer, which resulted in a mean deficit of surface solar radiation up to 200 Wm-2. Despite the Pantanal biomes' massive burning in 2020, the regional smoke plume was not far from its climatological features. Nevertheless, the Pantanal 2020 burning season represents the worst combination of a climate extreme applied to a fire-prone environment, coupled with inadequately enforced environmental regulations, from which there is much to be learned. [ABSTRACT FROM AUTHOR]

Eucalyptus (Eucalyptus spp.) is the main tree cultivated for cellulose pulp production in Brazil and is raised in large-scale monocrop plantations based on a two-dimensional system (rows and lines) of trees of the same age and hence height. There are opportunities to incorporate these huge plantations into agroforestry systems to create ecologically designed production systems. Plants respond to environment by modifying their structures, which in turn mediate their relationships with the available solar radiation—the main parameter affecting plant performance, provided other minimum conditions are met. In this way, it is possible to design a new system as a whole in view of maximizing solar radiation absorption and thus productivity. A tridimensional structure intermediated by a planting time scale (the fourth dimension) was designed on a conventional grid system. The Wave Project, which started in 2009, uses this concept to create a canopy with a wave-like appearance and to have production waves spaced in time. Eucalyptus was planted in alleys and monocrop (for comparison purposes) all at the same spacing (3 × 2 m) at different times. The different heights of neighboring Eucalyptus (the third dimension) allowed a much higher solar radiation exposure. With such an arrangement trees were allowed to present architecture modification in relation to those in monocrop conditions. Trees were able to greatly expand their canopies when exposed to increasing solar radiation availability, thus improving their growth rates. The use of the other two dimensions (height and time) is greatly ignored. With the time scale it is possible to design production systems that evolve. The adjustment of the temporal issue to plants' development and systems' architecture management presents a great possibility of increases on production with ecological adjustments—still unexplored. [ABSTRACT FROM AUTHOR]

Incident solar radiation on photovoltaic (PV) solar panels is not constant throughout the year. Besides dependence on the season, solar radiation is reliant on the location and weather conditions. For a given location on Earth, the best-fixed orientation of a PV panel can be determined by achieving the maximum incident solar irradiance throughout the year or for a predetermined period. In this paper, we use a sophisticated atmospheric radiative transfer model to calculate the direct and diffuse solar irradiation (radiant exposure) for the solar spectrum incident on PV solar panels to determine the best tilt angle of the panel in order to maximize absorption of solar radiation for selected periods. We used the Regula-Falsi numerical method to obtain the tilt angle at which the derivative of solar irradiation (concerning the tilt angle) approaches zero. Moreover, the spectral response of typical silicon cells is taken into account. These calculations were carried out in São Carlos (SP), a town in the southeast of Brazil. The best tilt angle was obtained for three selected periods. Additionally, we provide results for Southern latitudes ranging from 0° to −55° in steps of −5° for the meteorological seasons. We have shown that for each period, there is an increase in solar radiation absorption compared to the traditional installation angle based exclusively on the local latitude. These calculations can be extended to any location. [ABSTRACT FROM AUTHOR]

A ground gamma-ray survey was conducted over part of a large granitic body located near the city of Campinas, eastern São Paulo State, Brazil. The dominant rock types are K-feldspar porphyries-rich granites, porphyritic biotite and hornblend-bearing granites, fine to medium-grained monzogranites and medium to gross grained, biotite and muscovite-bearing monzogranites. The radioactive element distribution reflects local geology, in part re-worked by weathering, and the most radioactive rocks are the K-feldspar-rich granites. The rate of the absorbed dose by the air reflects the integrated effects of the radioactive elements distribution. Most of the observed values vary between 67 and 130 nGy h−1 and with localised spots with the absorbed dose rate values up to 193 nGy h−1 and low values of ∼25 nGy h−1. The mean air absorbed dose rate for the studied area is 77 nGy h−1. [ABSTRACT FROM PUBLISHER]