The COVID-19 pandemic introduced a significant decrease in industrial activities and other anthropic interventions on the environment, followed by a reduction of the emission of pollutant gases and aerosols. Monitoring of air quality is commonly performed through automatic stations, which can provide nearly real-time, accurate information. However, stations located in urban areas are subject to maintenance problems and extensive coverage for large areas is not feasible. As an alternative approach, data from orbital sensors can provide useful information for large areas at a low cost. Consequently, this study aimed to analyze the partial COVID-19 lockdown effect in atmospheric pollutants and indirect impact in UV radiation in Rio Grande do Sul, Brazil. Data on concentrations of nitrogen dioxide (NO₂), total ozone (O₃), and ultraviolet index (UVI) acquired by the OMI sensor aboard the Aura satellite were accessed for May, for the entire period 2010 to 2018, 2019, and 2020. Differences between these time series were calculated. Results showed significant reductions in nitrogen dioxide in most of the study area by as much as 33.9%, followed by increases in total ozone of up to 3.5% and the ultraviolet index by up to 4.8%. Although NO₂ plays a fundamental role in stratospheric chemistry, our results suggest that its decrease in 2020 was not directly responsible for the increase in total O₃; however, NO₂ was partially the cause for the increase in UVI, which in turn led to the heating of the stratosphere, generating an increase in ozone.

Pristimantis lassoalcalai Barrio-Amorós, Rojas-Runjaic & Barros, 2010 is a poorly known terrarana, endemic to the eastern slope of Sierra de Perijá in Venezuela. Although a close relationship of this species with Tachiramantis has been suspected based on its overall morphological similarity, this relationship had not been tested so far. On the basis of molecular data (two fragments of the 12S and 16S mtDNA genes) obtained from the type series, we reconstruct its evolutionary relationships and establish its phylogenetic position as a member of Tachiramantis. Based on this phylogenetic hypothesis, we transfer Pristimantis lassoalcalai to Tachiramantis as Tachiramantis lassoalcalai comb. nov. In addition, we describe its advertisement call. This is the fourth known species of the genus and the second to which its vocalization is described.

Ultraviolet radiation (UVR) plays a key role in the photochemistry of the atmosphere, through absorption or dispersion processes by its constituents (ozone, cloudiness, aerosols, and pollutants in the troposphere). Quantifying UVR in a spatial-temporal way and knowing its relationships with modulating variables is important for Rio Grande do Sul State, a region with one of the highest skin neoplasms rates in Brazil. Ultraviolet radiation data for the region, acquired by the Ozone Monitoring Instrument (OMI) for the 2006 to 2020 period, and expressed in terms of Erythemal Daily Dose (EDD), was used in this study, with the objectives of quantifying UVR incidence, its stability in time and spatial distribution. Our results show that for this study area the radiation varies from 3300 to 3700 J/m², with a latitudinal gradient of 66.7 J/m² per degree, with maxima recorded in December (6028 J/m², summer) and minima in June (1123 J/m², winter). 29.76% of the area had a long-term decreasing trend (z value =5), while 6.19% of the area had an increasing trend (z value=2). During the studied period of fifteen years, occurrences of high values of Erythemal Daily Dose are negatively correlated with Total O₃ as the dominant relationship, being also recorded positive or negative correlations with Total NO₂, depending of the investigated epoch or region.

A radiação solar incide na superfície da Terra sob condições atmosféricas diferentes, o que afeta a quantidade da radiação obtida na superfície terrestre durante o dia. A partir da razão entre irradiância global solar medida na superfície e a irradiância no topo da atmosfera (índice de claridade), pode-se estimar a quantidade de radiação solar global incidente em várias condições do céu. Desde março de 2018 a estação solarimétrica da UERGS, localizada na cidade de Porto Alegre - RS (-30.080022, -51.12856) vem registrando dados de radiação solar e outros parâmetros meteorológicos. Neste trabalho analisamos os dados obtidos para as componentes direta, difusa e global da radiação solar e o comportamento da radiação solar em três cenários de nebulosidade (céu claro, cobertura intermédia e nublado) por meio do índice de claridade “Kt”, a partir dos dados diários registrados pela estação durante um ano (março 2018 a fevereiro 2019). Como resultado obteve se, 72 dias com céu claro, 184 dias com cobertura intermédia e 109 dias nublado; com radiação média de 285 W/m2 em dias de céu claro, 187 W/m2 em cobertura intermédia, 76 W/m2 em dias nublados; sendo os meses de novembro e dezembro os que apresentaram a maior quantidade de dias com céu claro. Nos três cenários a irradiância global apresentou um comportamento exponencial conforme aumentou o índice Kt; entanto que, o comportamento da difusa e direta variou conforme o cenário, sendo a relação destas a determinante de cada categoria.

Solar energy has shown rapid and sustainable growth in Brazil over the last few years. The drop in costs of solar systems, regulation and government incentives has contributed to the increase of all types of solar energy applications, whether for energy, lighting, heating and other uses. In the same way, there is an increase in the demand for more detailed and qualified data regarding the behavior of solar radiation on the Earth's surface to improve the performance of projects that use this energy as their main source. Only information about the average annual or monthly values of solar energy available on the surface is insufficient for the correct modeling of large-scale systems or systems that use energy storage. This work aims to analyze the behavior of the distribution of horizontal daily global solar radiation in the city of Porto Alegre, Rio Grande do Sul (Latitude -30.05 and Longitude -51.16), through data collected between 2001 and 2014 by the automatic weather station (EMA) of the National Institute of Meteorology (INMET). From the treated, qualified, and analyzed horizontal global solar radiation data, information was obtained on the daily, monthly, seasonal and annual frequency distribution of the horizontal daily global radiation. The annual average value for the daily horizontal global solar radiation was 1533 kWh/m² with a standard deviation of 65.26 kWh/m² and a coefficient of variation equal to 4.25%. The monthly averages integrated from the daily values show maximum values in January (6.23 kWh/m²) and minimum values in June (2.16 kWh/m²). A energia solar apresenta um rápido e sustentável crescimento no Brasil ao longo dos últimos anos. A queda nos custos dos sistemas solares, regulamentação e os incentivos governamentais vem colaborando para o aumento de todos os tipos de aplicações de energia solar, sejam eles para geração de energia, iluminação, aquecimento e demais aproveitamentos. Observa-se do mesmo modo um aumento da demanda por dados mais detalhados e qualificados a respeito do comportamento da radiação solar na superfície terrestre com o intuito de aperfeiçoar o desempenho de projetos que utilizam essa energia como sua fonte principal. Apenas informações sobre os valores médios anuais ou mensais da energia solar disponível na superfície são insuficientes para a modelagem correta de sistemas de grande porte ou que utilizam armazenamento de energia. Este trabalho tem como objetivo analisar o comportamento da distribuição da radiação solar global diária horizontal na cidade de Porto Alegre, Rio Grande do Sul (Latitude -30,05 e Longitude -51,16), por meio de dados coletados entre 2001 e 2014 pela Estação Meteorológica Automática (EMA) do Instituto Nacional de Meteorologia (INMET). A partir dos dados de radiação solar global horizontal tratados, qualificados e analisados, foram obtidas informações sobre a distribuição de frequência diária, mensal, sazonal e anual da radiação global diária horizontal. O valor médio anual acumulado para a radiação solar global horizontal diária foi de 1533 kWh/m² com desvio padrão de 65,26 kWh/m² e coeficiente de variação igual a 4,25%. As médias mensais integradas a partir dos valores diários apresentam valores máximos em janeiro (6,23 kWh/m²) e mínimo em junho (2,16 kWh/m²).