scholarly journals Temperature decrease in the extratropics of South America in response to a tropical forcing during the austral winter

2010 ◽  
Vol 28 (1) ◽  
pp. 1-9 ◽  
Author(s):  
G. V. Müller
Keyword(s):  
South America ◽  
Equation Model ◽  
Austral Winter ◽  
Thermal Forcing ◽  
Minimum Frequency ◽  
Tropical Forcing ◽  
Teleconnection Patterns ◽  
The Pacific ◽  
The Mean ◽  
Favorable Conditions

Abstract. This paper focuses on the dynamic mechanisms that create favorable conditions for the occurrence of frosts that affect large areas of Argentina and are denominated generalized frosts (GF). The hemispheric teleconnection patterns linked to extreme cold events affecting central and northeastern Argentina during winter are identified. The objective is to determine whether the conditions found in previous studies for the composite of winters with extreme (maximum and minimum) frequency of GF occurrence respond to typical characteristics of the austral winter or they are inherent to those particular winters. Taking the mean winter as basic state in the 1961–1990 period, a series of numerical experiments are run using a primitive equation model in which waves are excited with a thermal forcing. The positions of the thermal forcing are chosen according to observed convection anomalies in a basic state given by the austral winters with extreme frequency of GF occurrence. The wave trains excited by anomalous convection situated in specific regions may propagate across the Pacific Ocean and reach South America with the appropriate phase, creating the local favorable conditions for the occurrence of GF. However, the anomalous convection is, by itself, not sufficient since the response also depends on the basic state configuration. This is proved by placing the forcing over the region of significant anomalous convection for maximum and minimum frequency of GF occurrence and the response was very different in comparison to the mean winter. It is concluded that the conditions for a greater GF frequency of occurrence are inherent to these particular winters, so that such conditions are not present in the average winter.

scholarly journals Warm and Dry Spells (WDS) in Austral Winter over Central South America

2007 ◽  
Vol 25 (5) ◽  
pp. 1049-1069 ◽  
Author(s):  
P. Satyamurty ◽  
M. da Silva Teixeira ◽  
C. Klug Padilha
Keyword(s):  
South America ◽  
Lower Troposphere ◽  
Hadley Circulation ◽  
Surface Characteristics ◽  
Specific Humidity ◽  
Meridional Plane ◽  
Central Brazil ◽  
The Pacific ◽  
Dry Spells ◽  
The Mean

Abstract. The horizontal and vertical structure of unusually warm and dry spells (WDS) over the central parts of South America during the winter and post-winter months (JJAS) are studied. During WDS the mean temperature and humidity anomalies over central Brazil are about +4.1°C and −13.2%, respectively. The mean duration of WDS is 11 days and their mean frequency is less than one per year during the months of JJAS. Apparently, WDS have no preference for the phase of ENSO. Widespread and persistent subsidence in the middle troposphere is observed in tropical Brazil during WDS, which renders the lower tropospheric air warm and dry. The negative anomalies of the specific humidity are observed to be associated with the subsidence regions. A strong, slow moving ridge in the eastern South Pacific and a low-pressure center in northern Argentina are important surface characteristics during the WDS. A more detailed investigation of two specific WDS events, a strong event (August–September 1999) and a moderate one (June 2002), shows a blocking-like situation in the 500-hPa geopotential and surface pressure fields in the Pacific. The South Atlantic subtropical high somewhat approaches the continent. Strong northerlies over the central and eastern parts of Brazil are also observed in the lower troposphere. During WDS the regional circulation acquires summertime characteristics, except for the absence of precipitation, and the circulation in the meridional plane is in the opposite sense from the Hadley circulation. A frontal system, supported by a 500-hPa trough, advances into central Brazil, causing the dissipation of the anomalous situation.

scholarly journals Establishing Normative Data on Singing Voice Parameters of Children and Adolescents with Average Singing Activity Using the Voice Range Profile

2021 ◽  
pp. 1-12
Author(s):  
Tobias Dienerowitz ◽  
Thomas Peschel ◽  
Mandy Vogel ◽  
Tanja Poulain ◽  
Christoph Engel ◽  
...  
Keyword(s):  
Socioeconomic Status ◽  
Normative Data ◽  
Clinical Diagnostics ◽  
Singing Voice ◽  
Minimum Frequency ◽  
Range Profile ◽  
Percentile Curves ◽  
The Mean ◽  
Voice Range ◽  
The Voice

<b><i>Purpose:</i></b> The purpose of this study was to establish and characterize age- and gender-specific normative data of the singing voice using the voice range profile for clinical diagnostics. Furthermore, associations between the singing voice and the socioeconomic status were examined. <b><i>Methods:</i></b> Singing voice profiles of 1,578 mostly untrained children aged between 7.0 and 16.11 years were analyzed. Participants had to reproduce sung tones at defined pitches, resulting in maximum and minimum fundamental frequency and sound pressure level (SPL). In addition, maximum phonation time (MPT) was measured. Percentile curves of frequency, SPL and MPT were estimated. To examine the associations of socioeconomic status, multivariate analyses adjusted for age and sex were performed. <b><i>Results:</i></b> In boys, the mean of the highest frequency was 750.9 Hz and lowered to 397.1 Hz with increasing age. Similarly, the minimum frequency was 194.4 Hz and lowered to 91.9 Hz. In girls, the mean maximum frequency decreased from 754.9 to 725.3 Hz. The mean minimum frequency lowered from 202.4 to 175.0 Hz. For both sexes, the mean frequency range ∆f showed a constant range of roughly 24 semitones. The MPT increased with age, for boys and girls. There was neither an effect of age nor sex on SPL<sub>min</sub> or SPL<sub>max</sub>, ranging between 52.6 and 54.1 dBA and between 86.5 and 82.8 dBA, respectively. Socioeconomic status was not associated with the above-mentioned variables. <b><i>Conclusion:</i></b> To our knowledge, this study is the first to present large normative data on the singing voice in childhood and adolescence based on a high number of measurements. In addition, we provide percentile curves for practical application in clinic and vocal pedagogy which may be applied to distinguish between normal and pathological singing voice.

Past Sea Surface Temperature of the Pacific Ocean of South America a Reference for Environmental Archeology

2022 ◽  
Author(s):  
Hector Luis D’Antoni ◽  
Lidia Susana Burry ◽  
Patricia Irene Palacio ◽  
Matilde Elena Trivi ◽  
Mariano Somoza
Keyword(s):  
Pacific Ocean ◽  
South America ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Sea Surface ◽  
The Pacific ◽  
The Pacific Ocean

Interdecadal changes in the interannual variability of the summer temperature over Northeast Asia

2021 ◽  
pp. 1-50
Author(s):  
Ruidan Chen ◽  
Zhiping Wen ◽  
Riyu Lu ◽  
Wenjun Liu
Keyword(s):  
Interannual Variability ◽  
Northeast Asia ◽  
Tropical Indian Ocean ◽  
Summer Temperature ◽  
Atmospheric Variability ◽  
The Pacific ◽  
The Mean ◽  
Southeastern Tropical Indian Ocean ◽  
Interdecadal Changes ◽  
Mean State

AbstractThis study reveals the interdecadal changes in the interannual variability of the summer temperature over Northeast Asia (NEA), which presents an enhancement around the early 1990s and a reduction after the mid-2000s. The stronger NEA temperature variability after the early 1990s is favored by the enhanced influence of the Pacific–Japan (PJ) teleconnection, which is remotely modulated by the southeastern tropical Indian Ocean (SETIO). After the early 1990s, the mean state over the SETIO presents relatively warmer SST and ascending motion, favoring a good relationship between the local SST and convection. Therefore, the SETIO SST could prominently influence the local convection and subsequently modulate the convection over the western North Pacific (WNP) via a cross-equatorial overturning circulation. The abnormal convection over the WNP further triggers the PJ teleconnection to influence NEA. However, these ocean–atmosphere processes disappear before the early 1990s. In this period, the mean state over the SETIO features relatively colder SST and subsiding motion, accompanied by a poor relationship between the local SST and convection. Therefore, the variability of convection over the SETIO is weak, thus the atmospheric variability over the WNP is also weakened and the PJ teleconnection presents a different distribution that could not influence NEA. The reduced variability of NEA temperature after the mid-2000s is related to the feeble influence of the PJ teleconnection and the reduced variability of the SETIO SST, which is modulated by the SST over the tropical central–eastern Pacific during the preceding winter to spring.

scholarly journals Fishing effects on elasmobranchs from the Pacific Coast of Colombia

2016 ◽  
Vol 21 (1) ◽  
pp. 9 ◽  
Author(s):  
Andrés Felipe Navia ◽  
Paola Andrea Mejía-Falla
Keyword(s):  
Species Composition ◽  
Pacific Coast ◽  
Trophic Levels ◽  
Functional Level ◽  
The Pacific ◽  
The Mean ◽  
The Stability ◽  
Large Predators ◽  
Average Catch ◽  
Index Of Diversity

<p>During 1995, 2001, 2003, 2004 and 2007; we studied the temporal variation in the structure of the elasmobranch assemblage along the Colombian Pacific coast using: the community index of diversity, heterogeneity, equitability, species composition, average catch sizes, and mean trophic levels. A total of 1 711 specimens from 19 species<br />(7 sharks and 12 rays) were collected during the 90 trawling operations. The number of species captured varied between 7 (1995) and 12 (2007) demonstrating a trend towards an imbalance in the assemblage attributes. In 1995, the mean trophic level (TLm) of the assemblage was 3.60, but in 2007 it decreased to 3.55 when the functional level of large predators was absent (TL ≥ 4). These results suggest changes in species composition, structural attributes, and a reduction of the highest functional level. Alterations to the catch proportions were also found: i.e. a greater abundance of rays of lower trophic levels. This study suggests an effect of trawling on the stability of this tropical coastal ecosystem.</p>

Confronting a Mercantile Elite: Bourbon Reformers and the Merchants of Lima, 1765–1796

2004 ◽  
Vol 60 (04) ◽  
pp. 519-558
Author(s):  
Patricia H. Marks
Keyword(s):  
South America ◽  
Pacific Coast ◽  
Point Of View ◽  
Economic Effects ◽  
Port City ◽  
Tax Reforms ◽  
Positive Effects ◽  
Colonial Peru ◽  
The Pacific ◽  
Significant Change

After Spain’s defeat in the Seven Years’ War (1757-1763), when the British had occupied Havana and Manila, a series of territorial, commercial, and tax reforms brought significant change to the viceroyalty of Peru. Their economic effects have been matters for debate ever since. Some historians have emphasized their positive effects. Following promulgation of the Reglamento de comercio libre of 1778, the volume and value of European manufactures exported to the Pacific coast of Spanish South America increased. Lima and its port city, Callao, remained important as commercial centers of Spanish South America. But others suggest that the viceregal capital—home to a powerful mercantile elite, the magnates of the consulado (merchant guild) of Lima—suffered a decline in its economic fortunes, as did the entire viceroyalty. Support for this point of view was widespread in late colonial Peru. In spite of the evidence for growth, a rising chorus of complaint bemoaned the increasing poverty of the viceroyalty in general and Lima in particular. How can we account for this discrepancy?

scholarly journals Transmission dynamics of Zika virus in island populations: a modelling analysis of the 2013-14 French Polynesia outbreak

2016 ◽  
Author(s):  
Adam J. Kucharski ◽  
Sebastian Funk ◽  
Rosalind M. Eggo ◽  
Henri-Pierre Mallet ◽  
W. John Edmunds ◽  
...  
Keyword(s):  
South America ◽  
Dengue Virus ◽  
Zika Virus ◽  
French Polynesia ◽  
Neurological Complications ◽  
Transmission Dynamics ◽  
Guillain Barre Syndrome ◽  
Island Populations ◽  
The Pacific ◽  
Guillain Barré

AbstractBetween October 2013 and April 2014, more than 30,000 cases of Zika virus (ZIKV) disease were estimated to have attended healthcare facilities in French Polynesia. ZIKV has also been reported in Africa and Asia, and in 2015 the virus spread to South America and the Caribbean. Infection with ZIKV has been associated with neurological complications including Guillain-Barré Syndrome (GBS) and microcephaly, which led the World Health Organization to declare a Public Health Emergency of International Concern in February 2015. To better understand the transmission dynamics of ZIKV, we used a mathematical model to examine the 2013–14 outbreak on the six major archipelagos of French Polynesia. Our median estimates for the basic reproduction number ranged from 2.6–4.8, with an estimated 11.5% (95% CI: 7.32–17.9%) of total infections reported. As a result, we estimated that 94% (95% CI: 91–97%) of the total population of the six archipelagos were infected during the outbreak. Based on the demography of French Polynesia, our results imply that if ZIKV infection provides complete protection against future infection, it would take 12–20 years before there are a sufficient number of susceptible individuals for ZIKV to reemerge, which is on the same timescale as the circulation of dengue virus serotypes in the region. Our analysis suggests that ZIKV may exhibit similar dynamics to dengue virus in island populations, with transmission characterized by large, sporadic outbreaks with a high proportion of asymptomatic or unreported cases.Author SummarySince the first reported major outbreak of Zika virus disease in Micronesia in 2007, the virus has caused outbreaks throughout the Pacific and South America. Transmitted by the Aedes species of mosquitoes, the virus has been linked to possible neurological complications including Guillain-Barre Syndrome and microcephaly. To improve our understanding of the transmission dynamics of Zika virus in island populations, we analysed the 2013–14 outbreak on the six major archipelagos of French Polynesia. We found evidence that Zika virus infected the majority of population, but only around 12% of total infections on the archipelagos were reported as cases. If infection with Zika virus generates lifelong immunity, we estimate that it would take at least 15–20 years before there are enough susceptible people for the virus to reemerge. Our results suggest that Zika virus could exhibit similar dynamics to dengue virus in the Pacific, producing large but sporadic outbreaks in small island populations.

scholarly journals A Comparison of Equatorial Electrojet in Peru and East Brazil

2013 ◽  
Vol 7 (1) ◽  
pp. 29-36 ◽  
Author(s):  
R.G. Rastogi ◽  
H. Chandra ◽  
Rahul Shah ◽  
N.B. Trivedi ◽  
S.L. Fontes
Keyword(s):  
South America ◽  
Geomagnetic Field ◽  
Daily Variation ◽  
Equatorial Electrojet ◽  
Horizontal Component ◽  
Low Latitude ◽  
Vertical Field ◽  
The Mean ◽  
Western Side ◽  
The Magnetic Field

The paper describes the characteristics of the equatorial electrojet at Huancayo (HUA, 12.1oS, 75.3oW, inclination 1.5oN, declination 1.0oE) in western side of South America, where the geomagnetic field is aligned almost along the geographic meridian, and at Itinga (ITI, 4.3oS, 47.oW, inclination 1.4oN, declination 19.3oW) in eastern part of South America, where the geomagnetic field is aligned about 19o west of the geographic meridian; although the mean intensity of the magnetic field in the two regions are almost of the same order. Further comparisons are made of the current at Itinga and at Tatuoca (TTB, 1.2oS, 48.5oW, inclination 7.8o N, declination 18.7oW), a low latitude station in the same longitude sector. The daily range of horizontal component of the geomagnetic field, H, is shown to be almost 16% higher at HUA compared to that at ITI. The daily variation of the eastward field, Y, showed a strong minimum of -40 nT around 13-14 hr LT at ITI whereas very low values were observed at HUA with a positive peak of about 4 nT around 11- 12 hr LT. The vertical field, Z, showed abnormally large negative values of -70 nT at TTB around 13 hr LT. The day-today fluctuations of midday and midnight values of X field were positively correlated between HUA and ITI with a high correlation coefficient of 0.78 and 0.88 respectively. Values of Y field were also significantly positively correlated between HUA and ITI for midnight hours (0.72), while no correlation was observed for the midday hours. The midnight values of X field at HUA, ITI and TTB showed significant (0.90 or greater) correlation with Dst index. Correlation values of about 0.7 were observed between Dst and midday values of X at ITI and TTB and to a lesser degree (0.4) at HUA.

scholarly journals The Oxford Handbook of Evidentiality

2018 ◽  
Keyword(s):  
South America ◽  
Common Sense ◽  
Language Contact ◽  
State Of The Art ◽  
Information Source ◽  
Language History ◽  
The Pacific ◽  
Child Language Acquisition ◽  
North And South America ◽  
North And South

Every language has a way of saying how one knows what one is talking about, and what one thinks about what one knows. In some languages, one always has to specify the information source on which it is based—whether the speaker saw the event, or heard it, or inferred it based on something seen or on common sense, or was told about it by someone else. This is the essence of evidentiality, or grammatical marking of information source—an exciting category loved by linguists, journalists, and the general public. This volume provides a state-of-the art view of evidentiality in its various guises, their role in cognition and discourse, child language acquisition, language contact, and language history, with a specific focus on languages which have grammatical evidentials, including numerous languages from North and South America, Eurasia and the Pacific, and also Japanese, Korean, and signed languages.

scholarly journals Effect of Red tilapia (Oreochromis mossambicus × Oreochromis niloticus) on growth and survival of the pacific shrimp (Litopenaeus vannamei) in simultaneous polyculture under marine conditions//Efecto de la tilapia roja (Oreochromis mossambicus × Oreochromis niloticus) en el crecimiento y supervivencia del camarón (Litopenaeus vannamei) en policultivo simultáneo bajo condiciones marinas

Biotecnia ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 5-12
Author(s):  
Alejandro Mcdonal-Vera ◽  
Wilfrido M. Contreras-Sánchez ◽  
Neil J. Duncan ◽  
Kevin Fitzsimmons ◽  
Maria J. Contreras- García ◽  
...  
Keyword(s):  
Litopenaeus Vannamei ◽  
Oreochromis Niloticus ◽  
Oreochromis Mossambicus ◽  
Pacific White Shrimp ◽  
White Shrimp ◽  
Average Weight ◽  
Growth And Survival ◽  
Red Tilapia ◽  
The Pacific ◽  
The Mean

In the present investigation, we evaluated if the presence of tilapia affects growth and survival of shrimp during pre-growth and grow-out phases. In both experiments, we used a random-blocks design in a single earth pond (0.75 ha) that was prepared and divided into nine (7 x 30 m) enclosures that were considered to be three blocks of three enclosures each. Each randomly stocked block consisted on Pacific white shrimp Litopenaeus vannamei (30 shrimp/m2) and three different densities (0.0, 0.25 and 0.50 fish/m2) of red tilapia hybrids (Oreochromis mossambicus x Oreochromis niloticus) to give three different treatments with three replicates. The results from the pre-growth and grow-out experiments followed the same trend. In both cases, we found no significant statistical differences (P>0.05) in the final average weight of the shrimp. However, the experimental blocks had a significant (P<0.05) effect on the mean sample weight of shrimp. Shrimp in blocks B and C were significantly bigger than shrimp from block A (P<0.05). For both experiments, we found no effect of the presence of tilapias on survival or growth of shrimp.RESUMENEvaluamos si la presencia de tilapias libres afecta el crecimiento y la supervivencia de camarones en fase de preengorda y engorda. Para ambos experimentos, utilizamos un diseño de bloques al azar en un estanque rústico (0.75 ha) que fue preparado y dividido en nueve encierros (7 x 30 m), se formaron tres bloques con tres encierros cada uno. Cada encierro dentro de cada bloque fue aleatoriamente seleccionado para sembrar camarón blanco del Pacífico, Litopenaeus vannamei (30 camarones/m2) y tres diferentes densidades (0.0, 0.25 y 0.50 peces/m2) de híbrido de tilapia roja (Oreochromis mossambicus x Oreochromis niloticus) para formar tres tratamientos con tres réplicas. Los resultados del experimento de pre-engorda y engorda siguieron la misma tendencia. En ambos experimentos no encontramos diferencias estadísticamente en el crecimiento de los camarones ni en las tilapias. Sin embargo, los bloques experimentales presentaron diferencias significativas (P<0.05) en el peso promedio final. Los camarones de los bloques B y C fueron estadísticamente más grandes (P<0.05) que los del bloque A. Para las dos etapas de crecimiento de los camarones, no se observó un efecto de la presencia de tilapias sobre la sobrevivencia o crecimiento de los camarones.

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