scholarly journals Comparison of long term series of total ozone and NO<sub>2</sub> column measurements in the southern tropics by SAOZ/NDACC UV-Vis spectrometers and satellites

2013 ◽  
Vol 6 (3) ◽  
pp. 4851-4893 ◽  
Author(s):  
M. Pastel ◽  
J.-P. Pommereau ◽  
F. Goutail ◽  
A. Richter ◽  
A. Pazmiño ◽  
...  
Keyword(s):  
Indian Ocean ◽  
South America ◽  
Ozone Production ◽  
South American ◽  
American Continent ◽  
The South ◽  
Data Set ◽  
Equatorial Latitude ◽  
The Indian Ocean ◽  
South American Continent

Abstract. Long series of ozone and NO2 total column measurements at the Southern tropics are available from two ground-based SAOZ (Système d'Analyse par Observation Zenithale) UV-visible spectrometers operated within the NDACC (Network for the Detection of Amtospheric Composition Change) deployed in Bauru in S-E Brazil and Reunion Island in the S-W Indian Ocean in 1995 and 1993 respectively. Although at the same latitude, the data show larger columns of both species above the South American continent than above the Indian Ocean. For verifying the reliability of these data before carrying out trend analysis, they have been compared to satellites observations available during the same period. However, since no single satellite was operating from 1995 until present, the comparison requires the building of a composite, called merged satellites series. As systematic differences exist between the individual data sets because of the many differences between instruments, spectral ranges, absorption cross-sections, and retrieval procedures used, the building of such a composite requires thorough evaluation and normalisation of each. From comparisons with SAOZ, the merged satellite data set build with EP-TOMS from 1995 to 2004 and OMI-TOMS from 2005 to 2012 are found best for ozone in the Southern tropics. After correction for biases with SAOZ, both are confirming the larger ozone columns reported by SAOZ above South America compared to the Indian Ocean shown to origin from ozone production by lightning NOx (LNOx) over the continent in the summer and the advection from Africa of ozone produced by biomass burning emissions in the winter. For NO2, best matching the SAOZ is a combination of GOME GDP4 1996–2003 and SCIAMACHY 2003–2012 products, after correction for the photochemical diurnal change of the concentration of the species between the SAOZ twilight observations and the time of satellites overpasses. The merged data series built from the data of these two satellites fully confirms the larger NO2 column reported by SAOZ above the South American continent as well as and its seasonality. The 35% larger column above Brazil in the summer is shown to be due to the NOx production in the upper troposphere by the frequent lightning during the thunderstorm season, whereas the winter maximum is shown to come from the larger exchange of NOx rich air with mid-latitudes in the lower stratosphere due to the more equatorial latitude of the subtropical jet above South America compared to the Indian Ocean.

Israeli penetration in South America (1973-1947)

2021 ◽  
Vol 26 ◽  
pp. 1-23
Keyword(s):  
South America ◽  
Key Words ◽  
Decision Makers ◽  
The Political ◽  
South American ◽  
American Continent ◽  
The South ◽  
Political Decision ◽  
South American Continent

This research is an attempt to uncover the reality and method of Israeli penetration in the South American continent, and aims to draw attention to the weaknesses and mistakes in the role of Arab communities that they had to play in South America, and the position of Arab governments towards that continent. The research was divided into two main axes, as the first dealt with the means of Israeli penetration in South America until 1947, providing a brief overview of the roots of the penetration in the South American continent and the methods it adopted in achieving this. While the second axis focused on the stance of the South American countries on the Arab-Israeli conflict (1947-1973). However, the Israeli infiltration was affecting the political decision-makers in that continent towards the decision to partition Palestine up to the October 1973 war. Key words: the penetration, Palestine, Israel, immigration, Arabs, America

scholarly journals Subpolar High Anomaly Preconditioning Precipitation over South America

2010 ◽  
Vol 67 (5) ◽  
pp. 1526-1542 ◽  
Author(s):  
Silvina A. Solman ◽  
Isidoro Orlanski
Keyword(s):  
Pacific Ocean ◽  
South America ◽  
Rossby Wave ◽  
South American ◽  
American Continent ◽  
The South ◽  
South Pacific Ocean ◽  
Anomalous Circulation ◽  
Frontal Activity ◽  
South American Continent

Abstract The mechanisms associated with the intraseasonal variability of precipitation over South America during the spring season are investigated with emphasis on the influence of a quasi-stationary anomalous circulation over the southeastern South Pacific Ocean (SEP). A spectral analysis performed to the bandpass-filtered time series of daily precipitation anomalies for the La Plata Basin (LPB) and the South Atlantic convergence zone (SACZ) regions revealed several statistically relevant peaks corresponding to periods of roughly 23 days and 14–16 days—with the lower (higher) frequency peaks more prevalent for the SACZ (LPB). The large-scale circulation patterns preconditioning precipitation variability over both regions were explored by means of a regression analysis performed on the daily 500-hPa geopotential anomaly field provided by the NCEP–NCAR reanalysis dataset. The most prominent feature of the regression fields is the presence of a quasi-stationary anomalous anticyclonic (cyclonic) circulation over the southeastern South Pacific Ocean associated with positive rainfall anomalies over the LPB (SACZ) and, emanating from that high (low), an external Rossby wave propagating northeastward toward the South American continent. The synoptic-scale activity, quantified in terms of a frontal activity index, showed a strong influence on precipitation over the LPB and to a lesser extent over the SACZ. Moreover, the frontal activity is actually modulated by the anomalous high circulation over the SEP region. The behavior of this anomalous circulation may be supported by a positive feedback mechanism that can enhance the response of the high anomaly itself, which in turns reinforces the Rossby wave train propagating toward the South American continent.

scholarly journals First Record of an Anthurid Isopod, Cyathura Univam sp. n., on the South American Continent

1983 ◽  
Vol 53 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Lazare Botosaneanu
Keyword(s):  
South America ◽  
First Record ◽  
The Other ◽  
South American ◽  
American Continent ◽  
The South ◽  
South American Continent

Description of Cyathura univam sp. n. (Isopoda: Anthuridea), a depigmented and eyeless species from oligohaline cave water, at Mayorquines (Peninsula de Morocoy, Venezuela). This is the first species of the suborder to be found in South America. It is related to two stygobiont species, one from Curaçao and the other from Aruba.

scholarly journals Arrival and diversification of mabuyine skinks (Squamata: Scincidae) in the Neotropics based on a fossil-calibrated timetree

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e3194 ◽  
Author(s):  
Anieli Guirro Pereira ◽  
Carlos G. Schrago
Keyword(s):  
South America ◽  
New World ◽  
Phenotypic Traits ◽  
South American ◽  
Ancestral State ◽  
American Continent ◽  
The South ◽  
Diversification Rates ◽  
Mode Of Reproduction ◽  
South American Continent

BackgroundThe evolution of South American Mabuyinae skinks holds significant biogeographic interest because its sister lineage is distributed across the African continent and adjacent islands. Moreover, at least one insular species,Trachylepis atlantica, has independently reached the New World through transoceanic dispersal. To clarify the evolutionary history of both Neotropical lineages, this study aimed to infer an updated timescale using the largest species and gene sampling dataset ever assembled for this group. By extending the analysis to the Scincidae family, we could employ fossil information to estimate mabuyinae divergence times and carried out a formal statistical biogeography analysis. To unveil macroevolutionary patterns, we also inferred diversification rates for this lineage and evaluated whether the colonization of South American continent significantly altered the mode of Mabuyinae evolution.MethodsA time-calibrated phylogeny was inferred under the Bayesian framework employing fossil information. This timetree was used to (i) evaluate the historical biogeography of mabuiyines using the statistical approach implemented in BioGeoBEARS; (ii) estimate macroevolutionary diversification rates of the South American Mabuyinae lineages and the patterns of evolution of selected traits, namely, the mode of reproduction, body mass and snout–vent length; (iii) test the hypothesis of differential macroevolutionary patterns in South American lineages in BAMM and GeoSSE; and (iv) re-evaluate the ancestral state of the mode of reproduction of mabuyines.ResultsOur results corroborated the hypothesis that the occupation of the South American continent by Mabuyinae consisted of two independent dispersion events that occurred between the Oligocene and the Miocene. We found significant differences in speciation rates between the New World and the remaining Mabuyinae clades only in GeoSSE. The influence of phenotypic traits on diversification rates was not supported by any method. Ancestral state reconstruction suggested that the ancestor of South American mabuyine was likely viviparous.DiscussionOur analyses further corroborated the existence of a transoceanic connection between Africa and South America in the Eocene/Oligocene period (Atlantogea). Following colonization of the isolated South America and subsequent dispersal through the continent by the ancestral mabuyine stock, we detected no difference in macroevolutionary regimes of New World clades. This finding argued against the ecological opportunity model as an explanation for the diversity of living mabuyines.

scholarly journals Global and zonal tropospheric ozone variations from 2003–2011 as seen by SCIAMACHY

2015 ◽  
Vol 15 (17) ◽  
pp. 24085-24130 ◽  
Author(s):  
F. Ebojie ◽  
J. P. Burrows ◽  
C. Gebhardt ◽  
A. Ladstätter-Weißenmayer ◽  
C. von Savigny ◽  
...  
Keyword(s):  
North America ◽  
Linear Regression ◽  
South America ◽  
Tropospheric Ozone ◽  
South American ◽  
Multivariate Linear Regression Model ◽  
American Continent ◽  
The South ◽  
South American Continent ◽  
Ozone Variations

Abstract. An analysis of the tropospheric ozone (O3) columns (TOCs) derived from SCIAMACHY limb-nadir-matching (LNM) observations during 2003–2011, focusing on the zonal and global variations in TOC is described. The changes are derived using a multivariate linear regression model. TOC shows a change of −0.2 ± 0.4 % yr−1, 0.3 ± 0.4 % yr−1, 0.1 ± 0.5 % yr−1 and 0.1 ± 0.2 % yr−1, which are not statistically significant at the 2 σ level in the latitude bands 30–50° N, 20° S–0, 0–20° N and 50–30° S, respectively. Tropospheric O3 shows statistically significant increases over some regions of South Asia (1–3 % yr−1), the South American continent (up to 2 % yr−1), Alaska (up to 2 % yr−1) and around Congo in Africa (up to 2 % yr−1). Significant increase in TOC is derived from the continental outflows including those of Australia (up to 2 % yr−1), Eurasia (1–3 % yr−1) and the South America (up to 3 % yr−1). Significant decrease in TOC (up to −3 % yr−1) is observed over some regions of the continents of North America, Europe and South America. Over the Oceanic regions, significant decrease in TOC of about −2 % yr−1 is observed over the outflows of Europe and North America.

scholarly journals Multiple incursion pathways for Helicoverpa armigera in Brazil show its genetic diversity spreading in a connected world

2019 ◽  
Author(s):  
Jonas A. Arnemann ◽  
Stephen H. Roxburgh ◽  
Tom Walsh ◽  
Jerson V.C. Guedes ◽  
Karl H.J. Gordon ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Gene Flow ◽  
South America ◽  
New World ◽  
Flow Patterns ◽  
South American ◽  
Southern Brazil ◽  
American Continent ◽  
Central Brazil ◽  
South American Continent

AbstractThe Old World cotton bollworm Helicoverpa armigera was first detected in Brazil with subsequent reports from Paraguay, Argentina, Bolivia, and Uruguay. This pattern suggests that the H. armigera spread across the South American continent following incursions into northern/central Brazil, however, this hypothesis has not been tested. Here we compare northern and central Brazilian H. armigera mtDNA COI haplotypes with those from southern Brazil, Uruguay, Argentina, and Paraguay. We infer spatial genetic and gene flow patterns of this dispersive pest in the agricultural landscape of South America. We show that the spatial distribution of H. armigera mtDNA haplotypes and its inferred gene flow patterns in the southwestern region of South America exhibited signatures inconsistent with a single incursion hypothesis. Simulations on spatial distribution patterns show that the detection of rare and/or the absence of dominant mtDNA haplotypes in southern H. armigera populations are inconsistent with genetic signatures observed in northern and central Brazil. Incursions of H. armigera into the New World are therefore likely to have involved independent events in northern/central Brazil, and southern Brazil/Uruguay-Argentina-Paraguay. This study demonstrates the significant biosecurity challenges facing the South American continent, and highlights alternate pathways for introductions of alien species into the New World.

scholarly journals Multiple incursion pathways for Helicoverpa armigera in Brazil show its genetic diversity spreading in a connected world

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jonas Andre Arnemann ◽  
Stephen Roxburgh ◽  
Tom Walsh ◽  
Jerson Guedes ◽  
Karl Gordon ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Gene Flow ◽  
South America ◽  
New World ◽  
Flow Patterns ◽  
South American ◽  
Southern Brazil ◽  
American Continent ◽  
Central Brazil ◽  
South American Continent

AbstractThe Old World cotton bollworm Helicoverpa armigera was first detected in Brazil with subsequent reports from Paraguay, Argentina, Bolivia, and Uruguay. This pattern suggests that the H. armigera spread across the South American continent following incursions into northern/central Brazil, however, this hypothesis has not been tested. Here we compare northern and central Brazilian H. armigera mtDNA COI haplotypes with those from southern Brazil, Uruguay, Argentina, and Paraguay. We infer spatial genetic and gene flow patterns of this dispersive pest in the agricultural landscape of South America. We show that the spatial distribution of H. armigera mtDNA haplotypes and its inferred gene flow patterns in the southwestern region of South America exhibited signatures inconsistent with a single incursion hypothesis. Simulations on spatial distribution patterns show that the detection of rare and/or the absence of dominant mtDNA haplotypes in southern H. armigera populations are inconsistent with genetic signatures observed in northern and central Brazil. Incursions of H. armigera into the New World are therefore likely to have involved independent events in northern/central Brazil, and southern Brazil/Uruguay-Argentina-Paraguay. This study demonstrates the significant biosecurity challenges facing the South American continent, and highlights alternate pathways for introductions of alien species into the New World.

Remarks on the botany of the southern cold temperate zone

1960 ◽  
Vol 152 (949) ◽  
pp. 500-507 ◽  
Keyword(s):  
Floristic Composition ◽  
Temperate Zone ◽  
South American ◽  
Boreal Zone ◽  
American Continent ◽  
The South ◽  
Plant Life ◽  
South American Continent

The plant life of the southern cold temperate zone differs widely from that of the northern cold temperate zone not only in its floristic composition but also in its physiognomic types of vegetation. The latter difference is partly due to the fact that the austral zone concerned is cold temperate in a sense rather different from the corresponding boreal zone. Contrary to the great continents dominating the boreal cold temperate zone, the austral cold temperate zone consists mostly of a great ocean containing only a narrow extension of the South American continent and various islands. Owing to this difference the climates of the austral cold temperate zone are generally much more oceanic than those of the boreal cold temperate zone. Nowhere in the boreal zone do we find a climate with such small

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