South America

Satyamurty, Prakki; Nobre, Carlos A.; Dias, Pedro

doi:10.1007/978-1-935704-10-2_5

Cited by 144 publications

(118 citation statements)

References 52 publications

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“…This is because plumes of biomass burning typically follow a pathway in agreement with the dominant atmospheric circulation in the period from August to November, the peak of the biomass burning activity. During this period, a counterclockwise atmospheric circulation is established in Central Brazil (Satyamurty et al, 1998), which results in the formation of a preferential corridor where smoke flows to south/southeast of South America. This circulation pattern keeps Western and Central Amazonia relatively free of a significant influence of biomass burning emissions.…”

Section: Discussionmentioning

confidence: 99%

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

et al. 2012

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Abstract. In this analysis a 3.5 years data set of aerosol and precipitation chemistry, obtained in a remote site in Central Amazonia (Balbina, (1 • 55 S, 59 • 29 W, 174 m a.s.l.), about 200 km north of Manaus) is discussed. Aerosols were sampled using stacked filter units (SFU), which separate fine (d < 2.5 µm) and coarse mode (2.5 µm < d < 10.0 µm) aerosol particles. Filters were analyzed for particulate mass (PM), Equivalent Black Carbon (BC E ) and elemental composition by Particle Induced X-Ray Emission (PIXE). Rainwater samples were collected using a wet-only sampler and samples were analyzed for pH and ionic composition, which was determined using ionic chromatography (IC). Natural sources dominated the aerosol mass during the wet season, when it was predominantly of natural biogenic origin mostly in the coarse mode, which comprised up to 81 % of PM 10 . Biogenic aerosol from both primary emissions and secondary organic aerosol dominates the fine mode in the wet season, with very low concentrations (average 2.2 µg m −3 ). Soil dust was responsible for a minor fraction of the aerosol mass (less than 17 %). Sudden increases in the concentration of elements as Al, Ti and Fe were also observed, both in fine and coarse mode (mostly during the April-may months), which we attribute to episodes of Saharan dust transport. During the dry periods, a significant contribution to the fine aerosols loading was observed, due to the large-scale transport of smoke from biomass burning in other portions of the Amazon basin. This contribution is associated with the enhancement of the concentration of S, K, Zn and BC E . Chlorine, which is commonly associated to sea salt and also to biomass burning emissions, presented higher concentration not only during the dry season but also for the April-June months, due to the establishment of more favorable meteorological conditions to the transport of Atlantic air masses to Central Amazonia. The chemical composition of rainwater was similar to those ones observed in other remote sites in tropical forests. The volume-weighted mean (VWM) pH was 4.90. The most important contribution to acidity was from weak organic acids. The organic acidity was predominantly associated with the presence of acetic acid instead of formic acid, which is more often observed in pristine tropical areas. Wet deposition rates for major species did not differ significantly between dry and wet season, except for NH + 4 , citrate and acetate, which had smaller deposition rates during dry season. While biomass burning emissions were clearly identified in the aerosol component, it did not present a clear signature in rainwater. The biogenic component and the long-range transport of sea salt were observed both in aerosols and rainwater composition. The results shown here indicate that in Central Amazonia it is still possible to observe quite pristine atmospheric conditions, relatively free of anthropogenic influences.

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Section: Discussionmentioning

confidence: 99%

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

et al. 2012

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“…O maior tempo de permanência dos sistemas, no entanto, foi observado nos meses de verão, em associaçãoà atividade da Zona de Convergência do Atlântico Sul (ZCAS) (Satyamurty et al, 1998).…”

Section: Frentes Frias Na América Do Sulunclassified

Climatologia de frentes frias no litoral de Santa Catarina

Rodrigues¹,

Franco²,

Sugahara

2004

Rev. Bras. Geof.

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ABSTRACT.A climatology of cold fronts at the coast of State do Santa Catarina, Brazil, is established based on 10-year period (1990)(1991)(1992)(1993)(1994)(1995)(1996)(1997)(1998)(1999) of NCEP-NCAR reanalysis data. The cold front passages were objectively identified taking into account the wind shifts to a southerly direction, as well as the persistence of southerly wind for at least one day, and a decreasing of air temperature. The results show that, on the average, 3 to 4 cold fronts reach coast of Santa Catarina, each month, with an interval of 8 days. The composite data analysis, using the date of days of cold front passages at Santa Catarina as reference, shows clearly a climatological pattern of evolution, with cold front moving typically from southwest to northeast. In terms of seasonal mean, during winter, one day before reaching coast of Santa Catarina (day -1) the cold front is observed at Rio Grande do Sul. After passing at Santa Catarina (day 0), it continues to move equatorward, reaching the coast of Rio de Janeiro one day later (day +1), until it reaches latitudes close to 20˚S (day +2), in the its stage of dissipation. In the third day, after the passage at Santa Catarina, the cold front is no more observed. Similar pattern of evolution is observed during summer, though the cold fronts are less intense and of slightly more rapid dissipation.Keywords: climatology of cold fronts, movement of cold fronts, cold fronts at the coast of Santa Catarina, Brazil. RESUMO. Uma climatologia de frentes friasé estabelecida para o litoral do Estado de Santa Catarina, com base nos dados de reanálises do NCEP-NCAR, do períodode 10 anos, de 1990 a 1999. As passagens de frentes frias foram objetivamente identificadas levando em conta o giro do vento para direção sul, persistência do vento de sul por pelo menos um dia, e uma queda de temperatura do ar simultânea ao giro do vento ou até dois dias depois. Os resultados mostram que, na média, de 3 a 4 frentes frias atingem a costa de Santa Catarina, mensalmente, com um intervalo de 8 dias. As análises da composição de dados, usando como referência os dias de passagens de frentes frias em Santa Catarina, mostram claramente um padrão climatológico de evolução com frente fria movendo-se tipicamente de sudoeste para nordeste. Em termos das médias sazonais, durante o inverno, um dia antes da passagem em Santa Catarina (dia -1), a frente friaé observada no Rio Grande do Sul, e depois de passar por Santa Catarina (dia 0), continua avançando para latitudes mais baixas, alcançando o litoral do Rio de Janeiro um dia depois (dia +1), até atingir posteriormente latitude de aproximadamente 20˚S (dia +2), já em fase de dissipação. No terceiro dia após a passagem por Santa Catarina, ela nãoé mais identificada.Padrão climatológico de evolução semelhanteé observado no verão, embora nessaépoca as frentes frias tenham menor intensidade e dissipação ligeiramente mais rápida.Palavras-chave: climatologia das frentes frias, movimento das frentes frias, frentes frias no litoral de Santa Catar...

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“…It must be noted that in this sequence of fields each frame has a structure very similar to that of the mean surface pressure field described by the classic climatology (e.g. Taljaard et al, 1969;Satyamurty et al, 1998). The PC loadings time series for the first PS is in Figure 5(a) showing high correlation coefficients (near one) with many of the original sequences.…”

Section: Use Of the Pspa Approachmentioning

confidence: 57%

Principal sequence pattern analysis: a new approach to classifying the evolution of atmospheric systems

Compagnucci

Araneo

Canziani

2001

Intl Journal of Climatology

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A new eigentechnique approach, Principal Sequence Pattern Analysis (PSPA), is introduced for the analysis of spatial pattern sequence, as an extension of the traditional Principal Component Analysis set in the T-Mode. In this setting, the variables are sequences of k spatial fields of a given meteorological variable. PSPA is described and applied to a sample of 256 consecutive daily 1000 hPa geopotential height fields. The results of the application of the technique to 5-day sequences demonstrate the advantages of this procedure in identifying field pattern sequences, thereby allowing the determination of the evolution and development of the systems, together with cyclogenesis and anticyclogenesis processes.In order to complete the study, the more traditional Extended Empirical Orthogonal Function (EEOF) analysis, which is the S-mode equivalent of the PSPA, was applied to the same dataset. For EEOF, it was not possible to identify any real sequences that could correspond to the sequences of patterns yielded by the EEOF. Furthermore, the explained variance distribution in the EEOF was significantly different from that obtained with PSPA. Conversely, the PSPA approach allowed for the identification of the sequences corresponding to those sequences observed in the data. Using diagrams of the squares of the component loadings values, as a function of time, the study of the times of occurrence of dominant field characteristics was also possible. In other words, successful determination of periods where the basic flow was dominant and times when strongly perturbed transient events with a significant meridional component occurred, was facilitated by PSPA.

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South America

Cited by 144 publications

References 52 publications

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

Aerosol and precipitation chemistry measurements in a remote site in Central Amazonia: the role of biogenic contribution

Climatologia de frentes frias no litoral de Santa Catarina

Principal sequence pattern analysis: a new approach to classifying the evolution of atmospheric systems

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