Análise dos Esquemas de Superfície do Modelo WRF: Um Estudo de Caso para a Floresta Tropical Amazônica

O trabalho teve como objetivo testar os diferentes esquemas desuperfície acoplados ao modelo Weather Research and Forecasting (WRF)para uma área de floresta tropical na Amazônia. Os esquemas de superfícietestados foram: Noah-LSM, RUC-LSM e o esquema de difusão térmica,para o dia 02 de fevereiro de 2008 durante a estação chuvosa. Osfluxos de energia simulados foram comparados com as observações deuma torre de fluxo instalada na região. Os resultados preliminares indicaramque o esquema Noah-LSM foi o que melhor representou a partiçãodos fluxos de energia (H e LE) para aquela região

Diferença de concentrações de ozônio, nox e hidrocarbonetos não metano durante período da semana e finais de semana, na região metropolitana de São Paulo

Ozone and inhalable particulate matter are the major air pollutants in the Metropolitan Area of São Paulo, Brazil, a region that has more than 19 million inhabitants and approximately 7 million registered vehicles. Proximity of roadways, adjacent land use, and local circulation are just some of the factors that can affect the results of monitoring of pollutant concentrations. The so-called weekend effect (higher ozone concentrations on weekends than on weekdays) might be related to the fact that concentrations of ozone precursors, such as nitrogen oxides (NOx) and Non Methane-Hydrocarbon (NMHC), are relatively lower on weekends. This phenomenon has been reported in some areas of the United States since the 1970s. The differences between the concentrations of ozone in period of weekend and weekday, were obtained from analysis of data hourly average of CETESB for 2004, studied the precursors to the formation of troposphere ozone, the meteorological variables and traffic profile for RMSP. Because of the proximity to sources of emissions from the station Pinheiros showed higher concentrations of NO and NO² and greater variations to the periods weekend and weekday. With fewer vehicles circulating during the weekend, and consequently less emission of pollutants, it has cleaner air and less concentration of NO and NO², there is the ideal setting to the formation of troposphere ozone, despite the lower concentration of NO². The proximity with the source emissions, aided by the increased availability of solar radiation and the presence of ozone precursors, were factors conditions for the occurrence of weekend effect.O ozônio e o material particulado inalável são os mais importantes poluentes do ar na região metropolitana de São Paulo (RMSP). Esta região possui em torno de 19 milhões de habitantes e aproximadamente 7 milhões de veículos registrados. O efeito final de semana sobre a concentração de ozônio, caracterizado por concentrações ozônio mais elevadas no fim de semana quando comparadas aos dias de semana, pode está relacionado às concentrações relativamente baixas dos precursores do ozônio tais como o óxido de nitrogênio (NOx) e os Hidrocarbonetos Não Metano (NMHC) nos finais de semana. As diferenças existentes entre as concentrações de ozônio nos períodos de fim de semana e dias da semana, foram obtidas a partir de analises médias dos dados horários da CETESB para o ano de 2004, foram estudados os precursores para a formação do ozônio troposférico, as variáveis meteorológicas e o perfil horário do trafego veicular para a RMSP. Devido a proximidade com as fontes de emissão a estação de Pinheiros apresentou maiores concentrações de NO e NO² e maiores variações na concentração na comparação feita aos períodos. Com menos veículos circulando durante o período de final de semana e conseqüentemente menos emissão de poluentes, tem-se uma atmosfera mais limpa e menos concentração de NO e NO², configurando uma situação mais favorável para a formação de ozônio troposférico, apesar da menor concentração de NO². A proximidade da fonte de emissão de poluentes, auxiliados pela maior disponibilidade de radiação solar e a presença dos precursores da formação de ozônio, foram fatores condicionantes para a ocorrência do efeito final de semana

Fitossociologia de plantas daninhas na cultura do pimentão nos sistemas de plantio direto e convencional.

Objetivou-se com este trabalho realizar o estudo fitossociológico das plantas daninhas em área cultivada com pimentão nos sistemas de plantio direto (SPD) e convencional (SPC), na Universidade Federal Rural do Semi-Árido (UFERSA). Para cada sistema de plantio, aos 60 dias após o transplantio da cultura, foram realizadas 32 amostragens com quadrado vazado de 0,50 m de lado, onde as plantas daninhas foram coletadas ao nível do solo, separadas por espécie, contadas e levadas à estufa, até massa constante, para determinação da massa seca. A partir desses valores, determinaram-se as seguintes características: densidade, frequência, abundância, densidade relativa, frequência relativa, abundância relativa, massa seca relativa e índice de valor de importância relativa. Foram identificadas 18 espécies e 13 famílias botânicas; sendo a família Poaceae a mais representativa, seguida pela Amaranthaceae. Todas as espécies avaliadas estavam presentes no SPC, que apresentou densidade de 466,5 plantas m-2 com destaque para as espécies Cyperus rotundus e Triantema portulacastrum com 201 e 99 plantas m-2 respectivamente. No SPD, ocorreram 13 espécies com densidade de 79,12 plantas m-2, sendo o Phyllanthus tenellus e o Commelina benghalensis com maior densidade, embora, a espécie Croton lobatus tenha se destacado em relação às demais em relação ao acúmulo de massa seca. O sistema de plantio direto modificou a dinâmica da comunidade infestante, reduzindo a densidade total de plantas infestantes em 83,04% em relação ao plantio convencional

Ozone sounding in the Metropolitan Area of Sao Paulo, Brazil: Wet and dry season campaigns of 2006

In the Metropolitan Area of Sao Paulo (MASP), located in southeastern Brazil, surface ozone concentrations are often well above the national air quality standards. In this experimental study, we attempted to characterize the vertical profile of atmospheric ozone and transport of the ozone plume in the boundary layer, using data from the first ozone soundings ever taken in the MASP. In 2006, we launched fifteen ozonesondes: eight from 15 to 18 May (dry season); and seven from 30 October to 1 November (wet season). Vertical ozone mixing ratios in the troposphere were approximately 40 ppb, reaching maximum values of approximately 60 ppb during the dry-season campaign and approximately 100 ppb during the wet-season campaign. In the first and second campaigns, the mean tropospheric ozone column abundance was 28.2 and 41.3 DU, respectively, which can be attributed to the considerable variation in the annual temperature cycle over the region. To determine the effect that biomass burning has on ozone concentrations over the MASP, we analyzed wind trajectories and satellite-derived fire counts. We cannot state unequivocally that biomass burning contributed to higher ozone concentrations above the boundary layer during the experimental campaigns. In the boundary layer, ozone concentrations increase with altitude, peaking at the base of the inversion layer, suggesting that local emissions of volatile organic compounds and nitrogen oxides play a significant role in the lower troposphere over MASP, influencing ozone formation not only at the surface but also vertically in the atmosphere and in distant regions. (C) 2012 Elsevier Ltd. All rights reserved.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Sao Paulo Research Foundation)Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP, Sao Paulo Research Foundation) [03/06414-0

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora