Manutenção da circulação atmosférica sobre a América do Sul

Lima, Hermenio C.

doi:10.1590/s0102-261x1999000100012

Cited by 3 publications

(6 citation statements)

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“…He noted that the divergent pattern over South American sector suggests relatively wet conditions over the eastern equatorial Pacific and dry conditions over northeastern South America during 1986America during -1987America during , and the reverse during 1988America during -1989. This result was also verified by Lima (1996), with the regional energetic analysis over South America. Further, Pezzi et al (1996) noted that the jet stream of the South Hemisphere shows the seasonal and interannual variations in its climatological position.…”

Section: Local Kinetic Energy Considerationssupporting

confidence: 66%

“…The kinematic method was used for computing vertical motion, considering for the lower and upper boundary conditions (at level 1000 hPa and 50 hPa, respectively) a value of zero for ω. A linear mass adjustment in divergence field is made to reduce inherent observational errors (Lima, 1996). With these data at grid points the energy parameters were calculated.…”

Section: Methodsmentioning

confidence: 99%

“…The power spectrum of the time series of this energy terms was estimated by correlation coefficients, by fitting a "null" hypothesis continum to the spectrum for Markov red noise persistence at 95% (Mitchell et al, 1966). The procedure for computing power spectrum for this method is given in Lima (1996). The periodicities thus obtained were confirmed applying a 4 a order Butterworth bandpass filter (Murakami, 1979), considering different frequency bands and the statistical significance at 90% and 95% was calculated through χ 2 distribution.…”

Section: Methodsmentioning

confidence: 99%

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Energetics of the summer circulation over South America

Moscati

Rao

2001

Ann. Geophys.

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Abstract. We have investigated the energetics of the summer circulation over tropical and extratropical South America. The kinetic energy equations of divergent (Kχ ) and rotational (Kψ) motion are utilized. All the terms of these equations are calculated on each day for five summers (November-February 1985–1990), using global wind analysis from the National Meteorological Center (NMC), now National Centers for Environmental Prediction (NCEP). The regional kinetic energy balance showed that the energy cycle over South America during the summer is, A P E to Kχ through the term -χ∇2Φ,and Kχ to Kψ through the term f∇ψ ∙ ∇χ. In the literature, several dominant oscillation modes have been noted over South America, namely the annual cycle, inter-annual, seasonal, intraseasonal, and high frequency scales, as revised by Lima. Results of the power spectrum analysis of kinetic energy terms indicate several statistically significant peaks and these have been confirmed with a fouth-order Butterworth filter. A well-defined mode, with a period around 30 days, was detected in the terms -χ∇2Φ and f∇ψ ∙ ∇χ, likely associated with Madden-Julian Oscillation (MJO). Later, we discuss the local kinetic energy balance using Mak’s local energetics scheme. We attempted to verify how the intraseasonal component interacts with other dominant oscillations over South America, such as seasonal cycle and high frequency disturbances,. It is noted that the major interactions among the three temporal scales occur mainly close to the South Atlantic Convergence Zone (SACZ) region. The temporal scale interactions in the Bolivian High (BH) and Northeast Brazil Low (NL) are distinct, and the dominant temporal scales may change from year to year.Key words. Meteorology and atmospheric dynamics (climatology, general circulation, tropical meteorology)

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Section: Local Kinetic Energy Considerationssupporting

confidence: 66%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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Energetics of the summer circulation over South America

Moscati

Rao

2001

Ann. Geophys.

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“…High values of ozone concentrations are associated with low relative humidity values (R = -0.47). According to Lima et al (1996), the air circulation on the South America significantly modifies the winter season for summer, especially at high levels (250hPA), as seen in Figure 3, comparing the patterns of movement tropospheric climate these two stations, at low (850hPA) and at high levels (250hPa). At low levels, the flow pattern does not change significantly from summer to winter (Figures 3b and 3a).…”

Section: Resultsmentioning

confidence: 99%

Modeling of Ozone Due to Weather Conditions

Souza

Pavão

Pires

et al. 2013

ABClima

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Ozone concentrations are valuable indicators of possible health and environmental impacts. However, they are also used to monitor changes and trends in the sources of both ozone and its precursors. For this purpose, the influence of meteorological variables is a confusing factor. This study presents an analysis of 4 year of ozone concentrations measured in a Campo Grande-MSBrazil city. Firstly, the aim of this study was to perceive the daily, monthly and seasonal variation patterns of ozone concentrations. Diurnal cycles are presented by season and the fit of the data to a normal distribution is tested. In order to assess ozone behavior under weather conditions, local meteorological variables (wind direction and speed, temperature, relative humidity and rainfall) were monitored together with ozone concentrations. The main relationships we could observe in these analyses were then used to obtain a regression equation linking diurnal ozone concentrations with meteorological parameters. The developed model is capable of explaining over 70% of the variability in the ozone concentrations Keywords: Urban ozone; Campo Grande; Meteorological parameters. MODELAGEM DE OZÔNIO DEVIDO ÀS CONDIÇÕES METEOROLÓGICAS ResumoEstudos sobre a influência da poluição atmosférica na qualidade de vida do ser humano têm sido realizados com grande intensidade nos últimos anos. O objetivo desta pesquisa foi de desenvolver um modelo para prever as concentrações de ozônio em função das variáveis meteorológicas. As medidas de concentração do ozônio foram realizadas na Universidade Federal de Mato Grosso do Sul. Foram utilizados dados do período de 2004 a 2008. As variáveis preditoras referentes ao clima (umidade relativa, velocidade do vento, precipitação diária e temperatura) foram cedidas pela EMBRAPA-GADO de CORTE-Campo Grande-MS. As principais relações observadas nestas análises foram então usadas para obter uma equação de regressão que liga as concentrações de ozônio diurnas com parâmetros meteorológicos. O modelo desenvolvido é capaz de explicar mais de 70% da variabilidade nas concentrações de ozônio de superfície. Palavras chaves: ozônio urbano; Campo Grande; parâmetros meteorológicos.

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“…Observational studies suggest that the development of the Bolivian High, in summer, is associated with strong warming of the Earth's surface over the Bolivian Altiplano during this time of year, heating the tropospheric column and thus causing an increase in atmospheric thickness on the continent at this point, thus generating a cyclone at high levels. In addition, the moisture convergence at low levels from the humid air masses to the north/northeast (Amazon region) and east (Pantanal), reinforce the convection and hence the release of latent heat of condensation in the middle and upper troposphere [25], increasing rainfall over the Amazon region and the central part of Brazil and fueling the anti-cyclone high pressure Bolivian High. Opposite conditions occur in winter, when the region of upward movement over the Amazon in summer migrates to the extreme northwest of the South American continent, being located on Venezuela and Colombia in May and June.…”

Section: Resultsmentioning

confidence: 99%

Development of a Short-Term Ozone Prediction Tool in Campo Grande-MS-Brazil Area Based on Meteorological Variables

Souza¹,

Aristones²,

Pavão³

et al. 2014

OJAP

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The objective of this study was to develop a model to predict the concentration of ozone. The measurements of ozone were conducted at the Federal University of Mato Grosso do Sul. The predictor variables related to climate were supplied by Embrapa Gada de Corte. Analyses of the data show a strong correlation between ozone and wind speed (0.75), humidity (−0.64) and temperature (0.41), as the factors that affect levels of concentration ozone. The observed and predicted values of daily ozone had a correlation coefficient (R) of 0.69.

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Manutenção da circulação atmosférica sobre a América do Sul

Cited by 3 publications

References 0 publications

Energetics of the summer circulation over South America

Energetics of the summer circulation over South America

Modeling of Ozone Due to Weather Conditions

Development of a Short-Term Ozone Prediction Tool in Campo Grande-MS-Brazil Area Based on Meteorological Variables

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