Orientador: Rogerio Caetano Costa / Resumo: Farfantepenaeus brasiliensis and F. paulensis are commonly exploited in the north of São Paulo because of their commercial value. The evaluation of the state of conservation of these species is difficult to perform, since both are landed as pink shrimp, which generates scarce data and makes impossible reliable ecological analyzes. Thus, this study evaluated through Generalized Additive Models (GAMs) the juvenile catches per unit of effort in abundance (CPUEn) and biomass (CPUEw) of these species and their relationships with environmental factors in the Ubatuba Bay in an interval of 22 years (1995 to 2017). The F. paulensis CPUEn model showed high catches recorded in months of the first semester and a strong influence of years under such monthly patterns. Also, there was a greater abundance in increased pluviosity, Phi < 4.5 and in moderate and strong La Niña and El Niño. CPUEw varied through the years, with increase in biomass from 2005, and in rainy periods. The F. brasiliensis CPUEn model presented high abundance from January to May, specially from 2010. Higher catches were also recorded in El Niño events, as well in Phi < 4.5 and OM < 15. CPUEw was mainly influenced by Phi. Although juveniles of both species were present in the bay during the months prior to the closure season it seems that there is maintenance of populations. / Mestre

Long-term changes of El Niño/Southern Oscillation (ENSO) are studied with the ensemble run of Simple Ocean Data Assimilation (SODA 2.2.6) and the Coupled Model Intercomparison Project Phase 5 (CMIP5). An eight member ocean reanalyses (SODA 2.2.6) from 1871 to 2008 is produced by using forcing from eight ensemble members of an atmospheric reanalysis. The ensemble reanalysis shows that El Niño has prominent decadal variability. Weak El Niños occur throughout the entire record whereas the occurrence of strong El Niños varies, with strong El Niño at the beginning and end of the record. The strength of La Niña is weaker than for El Niño, and has less variability. Although for any given El Niño year all ensemble members show the occurrence of El Niño, in some ensemble members the El Niño is strong while in others it is weak. When the timing of the onset of Westerly Wind Bursts (WWBs) occurs earlier in the year and the strength of WWBs is stronger, strong El Niño occurs. To study the importance of the background state in the tropical Pacific Ocean on ENSO, long-term trends of tropical Pacific SST, wind stress, subsurface temperature and the sub-tropical cells (STCs) are analyzed. The reanalysis shows that there is a slight cooling trend of SST in the central tropical Pacific due to an enhanced tropical Pacific circulation. Subsurface temperature also has a cooling trend. The STCs, which consist of equatorial upwelling, Ekman transport, extra-tropical subduction and pycnocline transport from the sub-tropical to the tropical region, strengthen from 1900 to 2008. When the STCs are accelerated, equatorial upwelling increases bringing cold water from the subsurface that cools the surface. ENSO variability is also analyzed in the CMIP5 historical experiments. Results show that most of the models have a realistic representation of the strength of ENSO; however, the location of warming generally extends too far to the west. Overall, properties of ENSO do not show a significant change in most of the CMIP5 models. One distinguishing difference between the CMIP5 models and SODA 2.2.6 is that ENSO in SODA 2.2.6 has prominent asymmetry between El Niño and La Niña, whereas ENSO in the CMIP5 models tends to have fairly symmetric El Niño and La Niña. In contrast with the reanalysis most of the CMIP5 models have warming trends at the surface and the transport of the STCs has a decreasing trend.

No description available.

Recent scientific investigations of sub-millennial paleoceanographic variability have attempted to use the population statistics of single planktic foraminiferal δ18O in an attempt to characterize the variability of high-frequency signals such as the El Niño Southern Oscillation (ENSO). However, this approach is complicated by the relatively short lifespan of individual foraminifera (~2-4 weeks) compared to the time represented by a sediment sample of a marine core (decades to millennia). The resolving ability of individual foraminiferal analyses (IFA) is investigated through simulations on an idealized virtual sediment sample. We focus on ENSO-related sea-surface temperatures (SST) anomalies in the tropical Pacific Ocean (Niño3.4 region). We constrain uncertainties on the range and standard deviation associated with the IFA technique using a bootstrap Monte Carlo approach. Sensitivity to changes in ENSO amplitude and frequency and the influence of the seasonal cycle on IFA are investigated through the construction of synthetic time series containing different characteristics of variability. We find that the standard deviation and range of the population of individual foraminiferal δ18O may be used to detect ENSO amplitude changes at particular thresholds (though the uncertainty in range is much larger than in standard deviation); however, it is highly improbable that IFA can resolve changes in ENSO frequency. We also determine that the main driver of the IFA signal is ENSO amplitude as opposed to changes in the seasonal cycle although this is specific to Niño3.4 where the SST response to ENSO is maximal. Our results suggest that rigorous uncertainty analysis is crucial to the proper interpretation of IFA data and should become a standard in individual foraminiferal studies. / text

Este estudo teve por finalidade investigar a frequência e intensidade dos Sistemas Frontais (SF) avaliando-os com os episódios ENOS (El Niño Oscilação Sul) para o período da Primavera (SON) de 2000 a 2010 sobre o Estado do Rio Grande do Sul (RS). As análises mostraram que os anos em que se tem a menor ocorrência de SF estão associados principalmente a eventos de La Niña Fraco e Neutralidade. Em contrapartida, um número maior de Sistemas Frontais foi verificado com relação aos episódios de El Niño Moderado e Neutralidade. Especificamente, no que se refere à questão mensal, percebeu-se que no mês de Outubro há uma maior influência dos Sistemas Frontais do que em Setembro e Novembro. Outro fator pertinente e evidenciado deu-se pelas comparações entre o período escolhido (no qual não ocorreram eventos fortes) e os episódios de ENOS Fortes. Notou-se, neste caso, que não ocorreram variações impactantes no número de Sistemas Frontais, embora se tenha o conhecimento dos efeitos e alterações existentes nos padrões de circulação atmosférica devido à atuação dos fenômenos de escala interanual. Ainda, tendo a necessidade de ampliar a gama de entendimento, foi realizada uma abordagem com relação ao comportamento da precipitação em seis sub-regiões do Estado, onde se observou de forma geral, um aumento da precipitação em praticamente todas as áreas do RS, quando comparado com a média Histórica. Com isso, ressaltou-se que os volumes mensais abaixo da média Histórica estão ligados a episódios de Neutralidade. Já a normalidade do regime de precipitação, mostrou-se interligado em média para todas as regiões ao evento de El Niño e por último, as precipitações acima da normal climatológica estão mais presentes em condições de El Niño, mais especificamente de intensidade Moderada. Dentre as sub-regiões analisadas, destacou-se a parte Oeste do Estado por ter apresentado uma maior intensidade nos volumes de precipitação. Outro fator importante analisado foram os valores percentuais das precipitações derivadas dos sistemas frontais. Levando-se em conta a média das avaliações, verificou-se que as sub-regiões Sul e Sudoeste do Rio Grande do Sul são as mais influenciadas pelas passagens dos Sistemas Frontais, enquanto os menores impactos na precipitação podem ser notados nas regiões Central e Norte do Rio Grande do Sul. Além disso, realizou-se um estudo de caso para avaliar o comportamento dos Sistemas Frontais em episódios de ENOS diferentes, nos campos de pressão atmosférica e temperatura do ar. Logo, averigou-se que em um ano de Neutralidade, as passagens de SF sobre o Estado costumam ser mais prolongadas em sua duração de tempo, permanecendo mais dias, com algumas variações significativas nos campos meteorológicos observados. Enquanto para um ano referente à condição de El Niño Moderado, os Sistemas Frontais possuem, na maioria dos casos, uma duração de tempo menor, consequentemente com menores variações na temperatura e pressão. / This study aimed to investigate the frequency and intensity of the frontal systems (FS) evaluating them with respect to the episodes of El Niño – South Oscillation (ENSO) for the spring season (SON) from 2000 to 2010, over the state of Rio Grande do Sul (RS - Brazil). The analysis showed that the years having a smaller incidence of SF are mainly associated to events of weak La Nina and neutrality. In contrast, a larger number of frontal systems were observed with respect to episodes of moderate El Nino and neutrality. Specifically with relation to the monthly aspect, it was noticed that there is a major influence of the frontal systems in October than in September and November. Another inherent and evidenced factor was given by the comparisons between the selected period (with no occurrence of strong events) and the Strong ENSO episodes. In this case it was noticed that there has not occurred impacting variations in the number of frontal systems although the effects and changes of the atmospheric circulation patterns due to the action of the interannual scale phenomena are known. Further, to enlarge the range of understanding, it was made one approach relating to the precipitation behavior in six sub regions of the state where in general it was observed an increase in the precipitation almost in all areas of the RS when compared to the historic average. Thus, the monthly volumes below the historic average are linked to neutral episodes. Otherwise, the normal precipitation regime, on average, was proved to be interconnected for all regions to the event El Niño, and finally the rainfall above the climatology are more common in El Niño conditions, specifically with Moderate intensity. In this manner, considering the analyzed sub regions, the west part of the state has presented a higher intensity of precipitation volumes. Another important factor analyzed were the percentage values of rainfall derived from frontal systems. Taking into account the average of the evaluations, it was found that the South and southwest sub-region of Rio Grande do Sul is the most influenced by passages from the SF, while smaller impacts on precipitation can be noticed in the Central and North regions. In addition, it was realized a case study to evaluate the behavior of frontal systems in different episodes of ENSO, with respect to the fields of atmospheric pressure and air temperature. Thus, it was found that in a year of neutrality, the frontal systems crossings on the state tend to be more prolonged, remaining more days, with some significant variations in the observed meteorological fields. While for a year related to the condition of Moderate El Nino the frontal systems have, in mosta cases, a shorter duration, thus with minor variations in temperature and pressure.

Rapidly rising levels of atmospheric greenhouse gases including carbon dioxide and methane since the industrial revolution have drawn scientific attention to the importance of the global carbon cycle to the climate (Cubasch et al., 2013). Tropical peatlands, the majority of which are located in the Indonesian region, are a major source of uncertainty in the carbon cycle as the relationships between carbon accumulation and hydrological changes remain poorly understood (Hergoualc’h & Verchot, 2011, Page et al., 2011). An important driver of carbon emissions in tropical peatlands is fire, which in the Indonesian region is strongly influenced on interannual timescales by the El Niño/Southern Oscillation (ENSO). However, it is not clear how ENSO and fire have varied at decadal to centennial scales over the past two millennia. This thesis explores long term tropical hydrological variability and ENSO-like climate change from palaeorecords and their interactions with fire. Using a wide range of instrumental, proxy and model datasets and a novel reconstruction method, two separate reconstructions of long-term ENSO-like climate change are produced based on precipitation and temperature data. These show no evidence of a difference between the ENSO-like behaviour of precipitation and temperature. There is limited evidence for a difference in long-term ENSO-like state between the Medieval Climate Anomaly and the Little Ice Age. Reconstructions of hydrological variability and biomass burning in the Indonesian region suggest that precipitation and fire have been positively correlated over the past 2,000 years, which is contrary to the modern-day relationship on ENSO timescales. This throws up questions of long-term versus short-term interactions and feedbacks between fire, climate and vegetation. It is likely that anthropogenic activity in the Indonesian region has significantly altered the stability of the fire regime. Further research combining proxy data, climate and fire models, and using more robust statistical analysis is necessary to untangle the natural and anthropogenic driving factors at different time resolutions.

Este estudo teve por finalidade investigar a frequência e intensidade dos Sistemas Frontais (SF) avaliando-os com os episódios ENOS (El Niño Oscilação Sul) para o período da Primavera (SON) de 2000 a 2010 sobre o Estado do Rio Grande do Sul (RS). As análises mostraram que os anos em que se tem a menor ocorrência de SF estão associados principalmente a eventos de La Niña Fraco e Neutralidade. Em contrapartida, um número maior de Sistemas Frontais foi verificado com relação aos episódios de El Niño Moderado e Neutralidade. Especificamente, no que se refere à questão mensal, percebeu-se que no mês de Outubro há uma maior influência dos Sistemas Frontais do que em Setembro e Novembro. Outro fator pertinente e evidenciado deu-se pelas comparações entre o período escolhido (no qual não ocorreram eventos fortes) e os episódios de ENOS Fortes. Notou-se, neste caso, que não ocorreram variações impactantes no número de Sistemas Frontais, embora se tenha o conhecimento dos efeitos e alterações existentes nos padrões de circulação atmosférica devido à atuação dos fenômenos de escala interanual. Ainda, tendo a necessidade de ampliar a gama de entendimento, foi realizada uma abordagem com relação ao comportamento da precipitação em seis sub-regiões do Estado, onde se observou de forma geral, um aumento da precipitação em praticamente todas as áreas do RS, quando comparado com a média Histórica. Com isso, ressaltou-se que os volumes mensais abaixo da média Histórica estão ligados a episódios de Neutralidade. Já a normalidade do regime de precipitação, mostrou-se interligado em média para todas as regiões ao evento de El Niño e por último, as precipitações acima da normal climatológica estão mais presentes em condições de El Niño, mais especificamente de intensidade Moderada. Dentre as sub-regiões analisadas, destacou-se a parte Oeste do Estado por ter apresentado uma maior intensidade nos volumes de precipitação. Outro fator importante analisado foram os valores percentuais das precipitações derivadas dos sistemas frontais. Levando-se em conta a média das avaliações, verificou-se que as sub-regiões Sul e Sudoeste do Rio Grande do Sul são as mais influenciadas pelas passagens dos Sistemas Frontais, enquanto os menores impactos na precipitação podem ser notados nas regiões Central e Norte do Rio Grande do Sul. Além disso, realizou-se um estudo de caso para avaliar o comportamento dos Sistemas Frontais em episódios de ENOS diferentes, nos campos de pressão atmosférica e temperatura do ar. Logo, averigou-se que em um ano de Neutralidade, as passagens de SF sobre o Estado costumam ser mais prolongadas em sua duração de tempo, permanecendo mais dias, com algumas variações significativas nos campos meteorológicos observados. Enquanto para um ano referente à condição de El Niño Moderado, os Sistemas Frontais possuem, na maioria dos casos, uma duração de tempo menor, consequentemente com menores variações na temperatura e pressão. / This study aimed to investigate the frequency and intensity of the frontal systems (FS) evaluating them with respect to the episodes of El Niño – South Oscillation (ENSO) for the spring season (SON) from 2000 to 2010, over the state of Rio Grande do Sul (RS - Brazil). The analysis showed that the years having a smaller incidence of SF are mainly associated to events of weak La Nina and neutrality. In contrast, a larger number of frontal systems were observed with respect to episodes of moderate El Nino and neutrality. Specifically with relation to the monthly aspect, it was noticed that there is a major influence of the frontal systems in October than in September and November. Another inherent and evidenced factor was given by the comparisons between the selected period (with no occurrence of strong events) and the Strong ENSO episodes. In this case it was noticed that there has not occurred impacting variations in the number of frontal systems although the effects and changes of the atmospheric circulation patterns due to the action of the interannual scale phenomena are known. Further, to enlarge the range of understanding, it was made one approach relating to the precipitation behavior in six sub regions of the state where in general it was observed an increase in the precipitation almost in all areas of the RS when compared to the historic average. Thus, the monthly volumes below the historic average are linked to neutral episodes. Otherwise, the normal precipitation regime, on average, was proved to be interconnected for all regions to the event El Niño, and finally the rainfall above the climatology are more common in El Niño conditions, specifically with Moderate intensity. In this manner, considering the analyzed sub regions, the west part of the state has presented a higher intensity of precipitation volumes. Another important factor analyzed were the percentage values of rainfall derived from frontal systems. Taking into account the average of the evaluations, it was found that the South and southwest sub-region of Rio Grande do Sul is the most influenced by passages from the SF, while smaller impacts on precipitation can be noticed in the Central and North regions. In addition, it was realized a case study to evaluate the behavior of frontal systems in different episodes of ENSO, with respect to the fields of atmospheric pressure and air temperature. Thus, it was found that in a year of neutrality, the frontal systems crossings on the state tend to be more prolonged, remaining more days, with some significant variations in the observed meteorological fields. While for a year related to the condition of Moderate El Nino the frontal systems have, in mosta cases, a shorter duration, thus with minor variations in temperature and pressure.

Submitted by Amanda Silva (amanda.osilva2@ufpe.br) on 2015-03-04T11:54:59Z No. of bitstreams: 2 TESE IONEIDE ALVES.pdf: 6696005 bytes, checksum: 74feedc7fa319b8af78f93510cb5fdd0 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) / Made available in DSpace on 2015-03-04T11:54:59Z (GMT). No. of bitstreams: 2 TESE IONEIDE ALVES.pdf: 6696005 bytes, checksum: 74feedc7fa319b8af78f93510cb5fdd0 (MD5) license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Previous issue date: 2013 / Esta pesquisa teve como objetivo geral avaliar a variabilidade e as tendências dos índices de detecção de mudanças climáticas, déficit e excedente hídrico, na bacia do rio Una, PE, a partir da analise do comportamento da precipitação anual, semestral, mensal e diária. Foram consideradas 15 localidades que dispunham de dados pluviométricos diários e mensais no período de 1965 a 2006. Para a obtenção dos índices de tendência climática, utilizou-se o software RClimdex 2.9.0. A classificação dos anos extremos foi obtida através do índice de seca. Os anos extremos foram comparados com as anomalias das temperaturas da superfície do mar nos oceanos Pacífico e Atlântico. A identificação das áreas com déficit e excedente hídrico ocorreu por meio da estimativa do balanço hídrico climático, bem como a classificação das áreas de maiores e menores riscos climáticos. Os índices de detecção de mudanças climáticas apontaram tendência de redução de chuva em toda a extensão da bacia, aumento na quantidade de dias secos e diminuição dos dias úmidos, e tendência positiva na quantidade de dias com precipitações iguais e superiores a 50 mm por dia no Litoral (Barreiros). As áreas com maiores deficiência hídricas encontram-se no Agreste e com maior disponibilidade hídrica na Zona da Mata e no Litoral. A bacia do Una apresenta alta variabilidade na distribuição espacial e temporal da precipitação diária, mensal, sazonal e anual. Os padrões de variabilidades dos oceanos Pacífico e Atlântico influenciam no comportamento pluviométrico por intermédio dos fenômenos oceânico-atmosférico de grande escala ENOS, ODP e Dipolo do Atlântico.

Master of Science / Department of Agricultural Economics / Aleksan Shanoyan / With the recent increase in record-breaking weather events and the inherent susceptibility of the fishmeal industry to temperature fluctuations, the industry dynamics and sustainability of the Peruvian fishmeal sector has gained renewed attention. Among important causes of concern are the cyclical impact of El Niño Southern Oscillation (ENSO) events on productivity and profitability of fishmeal producing firms, long-term structural changes in the industry, and resulting socio-economic consequences. Although distinct risk management strategies have been implemented by industry players and a range of policy initiatives have been introduced by the government over the years, the firms in the Peruvian fishmeal industry remain highly susceptible to the effects of ENSO events. The increased frequency and magnitude of ENSO events over the past decade has forced relatively less resilient firms out of business and has been accompanied by an observable trend towards increased industry concentration. While there is a potential for efficiency gains and economies of scale from increased concentration, policy makers and industry players have concerns about negative social implications from declining numbers of small and medium firms and shifting competitive dynamics in the industry. As a result, policy-makers and industry stakeholders are in the continuous search for effective strategies and mechanisms for enhancing the resilience of individual fishmeal producers and the overall industry to the effects of ENSO events. The objective of this study is to expand the understanding of factors that affect the resilience of firms to ENSO events in the Peruvian fishmeal industry. The analysis is based on a panel database that combines information from the Peruvian Instituto Nacional de Estadística e Informática (Statistics Institute), Aduanet (Peruvian Customs website), and the Oceanic Niño Index (ONI). The objective is to identify firm characteristics and factors that can potentially enhance the resilience of a firm to the negative impacts of ENSO events. The specific period of study covers the ENSO event that lasted from July 2009 to April 2010. The resilience of individual firms is measured by applying system resilience framework proposed by Barroso et al. (2015). Subsequently, the effect of a range of characteristics on firm resilience is estimated using a fractional response logit method. Among key parameters of interest are the estimated effects of size, experience, location, and participation in government support programs. The results indicate positive relationship between resilience and experience, diversification, access to government subsidy programs, and share of imported inputs. The results also indicate a negative effect of firm size on resilience to ENSO events. The industry and policy implications of the findings are discussed, while highlighting the number of methodological limitations. The overall contribution of this study is twofold. First it presents an application of resilience triangle approach to measuring firm resilience in the context of Peruvian fishmeal industry. Second, it provides new insights on the factors affecting firm resilience to the negative impact of ENSO events. The findings have a potential to inform policy and industry initiatives designed to enhance the industry’s ability to cope with negative consequences of ENSO events.

The Indian Summer Monsoon (ISM) plays a vital role in the livelihoods and economy of those living on the Indian subcontinent, including the small, mountainous country of Bhutan. The ISM fluctuates over varying temporal scales and its variability is related to many internal and external factors including the El Niño Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD). In 2015, a Super El Niño occurred in the tropical Pacific alongside a positive IOD in the Indian Ocean and was followed in 2016 by a simultaneous La Niña and negative IOD. These events had worldwide repercussions. However, it is unclear how the ISM was affected during this time, both at a regional scale over the whole ISM area and at a local scale over Bhutan. First, an evaluation of data products comparing ERA5 reanalysis, TRMM and GPM satellite, and GPCC precipitation products against weather station measurements from Bhutan, showed that ERA5 reanalysis was the most suitable product to investigate ISM change in these two years. Using the reanalysis datasets, it was shown that there was disruption to the ISM during this period, with a late onset of the monsoon in 2015, a shifted monsoon flow in July 2015 and in August 2016 and a late withdrawal in 2016. However, this resulted in neither a monsoon surplus nor deficit across both years but instead large spatial-temporal variability. It is possible to attribute some of the regional scale changes to the ENSO and IOD events, but the expected impact of a simultaneous ENSO and IOD events are not recognisable. This may be due to a supposed weakening of the ENSO/ISM relationship and it is likely that 2015/16 monsoon disruption was driven by a combination of factors alongside ENSO and the IOD, including varying boundary conditions, the Pacific Decadal Oscillation, the Atlantic Multi-decadal Oscillation, and more. At a local scale, the intricate topography and orographic processes ongoing within Bhutan further amplified or dampened the already altered ISM. Whilst ENSO and IOD driven monsoon variability can be recognised at a regional scale, a direct link between ENSO and IOD activity and changes to the monsoon at a local scale over Bhutan is hard to distinguish. It is unknown how the ISM, ENSO, and the IOD will evolve under a future changing climate and therefore this presents a concern to Bhutan with its inherent vulnerability to monsoon variability.