The total extent of the atmospheric impacts associated to the aerosol black carbon (BC) emissions from South America is not completed described. This work presents results of BC monitored during three scientific expeditions (2002, 2003 and 2004) on board of a Brazilian oceanographic vessel Ary Rongel that covered the South-West Atlantic coast between 22-62°S. This latitudinal band encloses major urban regions of South America and the outflow region of the SACZ (South Atlantic Convergent Zone), which is an important mechanism of advective transport of heat, moisture, minor gases and aerosols from the South America continental land to the Southern Atlantic Ocean. Our results showed that aerosol BC enhanced concentrations from urban/industrial origin can be transported to the South-West Atlantic Ocean due to the migration of sub-polar fronts that frequently reach tropical/subtropical regions. Despite the decrease of aerosol BC concentrations southwards (from ∼1,200 ng m −3 at latitude 22°S to ∼10 ng m −3 at latitude 62°S), several observed peak events were attributed to regional urban activities. Most of such events could be explained by the use of air mass back trajectories analysis. In addition, a global model simulation is presented (Goddard Institute for Space Studies -GISS GCM BC simulation) to explore the origins of aerosol BC in the South-West Atlantic. The model allowed isolating the biomass emissions from South America and Africa and industrial (nonbiomass) pollution from other regions of the globe. This model suggests that the apportionment of about half of the aerosol BC at the South-West Atlantic may derive from South American biomass burning.
Abstract. Muscles of forty-four fish of two different species, Mugil spp and Micropogonia fumieri, and six composite samples of the shellfish Perna perna, collected in Guanabara Bay, a tropical estuary, were analysed for 3l0 Po and 2l0 Pb contents. The method for °Po determination consisted of spontaneous deposition on copper disks, followed by alfa counting. The method for :i0 Pb determination was mineralization followed by leaching, ionexchange separation, precipitation and, finally, beta counting. The average values found for concentration of 2l0 Po in fish was 2.6 Bq.kg" 1 , wet basis, while for shellfish the values were higher, reaching 43.8 Bq.kg"', wet basis. For 2l0 Pb, concentrations were very low, frequently below the detection limit for fish samples. For shellfish this was higher, reaching 1.8 Bq.kg" 1 , wet basis.
The Total Solar Irradiance (TSI), which is the total radiation arriving at Earth's atmosphere from the Sun, is one of the most important forcing of the Earths climate. Measurements of the TSI have been made employing instruments on board several space-based platforms during the last four solar cycles. However, combining these measurements is still challenging due to the degradation of the sensor elements and the long-term stability of the electronics. Here we describe the preliminary efforts to design an absolute radiometer based on the principle of electrical substitution that is under development at Brazilian's National Institute for Space Research (INPE).
Abstract.We describe the preliminary design of a magnetograph and visible-light imager instrument to study the solar dynamo processes through observations of the solar surface magnetic field distribution. The instrument will provide measurements of the vector magnetic field and of the line-of-sight velocity in the solar photosphere. As the magnetic field anchored at the solar surface produces most of the structures and energetic events in the upper solar atmosphere and significantly influences the heliosphere, the development of this instrument plays an important role in reaching the scientific goals of The Atmospheric and Space Science Coordination (CEA) at the Brazilian National Institute for Space Research (INPE). In particular, the CEA's space weather program will benefit most from the development of this technology. We expect that this project will be the starting point to establish a strong research program on Solar Physics in Brazil. Our main aim is acquiring progressively the know-how to build state-of-art solar vector magnetograph and visible-light imagers for space-based platforms to contribute to the efforts of the solar-terrestrial physics community to address the main unanswered questions on how our nearby Star works.
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