A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. July 2014. / South Africa’s climate is highly variable, implying that the national agricultural sector should make provision to have early warning services in place in order to reduce the risks of disasters. More than 70% of natural disasters worldwide are caused by weather and climate or weather and climate related hazards. Reliable Seasonal Climate Forecasting (SCF) for South Africa would have the potential to be of great benefit to users in addressing disaster risk reduction. A disaster is a serious disruption of the functioning of a community or a society, causing widespread human, material, economic or environmental losses, which exceed the ability of the affected community or society to cope when using their own resources. The negative impacts on agricultural production in South Africa due to natural disasters including disasters due to increasing climate variability and climate change are critical to the sector. The hypothesis assumed in the study is the improved early warning service and better SCF dissemination lead to more effective and better decision making for subsequent disaster risk reduction in the agricultural sector. The most important aspect of knowledge management in early warning operations is that of distributing the most useful service to the target group that needs it at the right time. This will not only ensure maximum performance of the entity responsible for issuing the early warnings, but will also ensure the maximum benefit to the target group. South Africa is becoming increasingly vulnerable to natural disasters that are afflicted by localised incidents of seasonal droughts, floods and flash floods that have devastating impacts on agriculture and food security. Such disasters might affect agricultural production decisions, as well as agricultural productivity. Planting dates and plant selection are decisions that depend on reliable and accurate meteorological and climatological knowledge and services for agriculture. Early warning services that could be used to facilitate informed decision making includes advisories on iv future soil moisture conditions in order to determine estimated planting times, on future grazing capacity, on future water availability and on forecasts of the following season’s weather and climate, whenever that is possible. The involvement of government structures, obviously, is also critical in immediate responses and long term interventions. The importance of creating awareness, of offering training workshops on climate knowledge and SCF, and of creating effective early warning services dissemination channels is realized by government. This is essential in order to put effective early warning services in place as a disaster-risk coping tool. Early warning services, however, can only be successful if the end-users are aware of what early warning systems, structures and technologies are in place, and if they are willing that those issuing the early warning services become involved in the decision-making process. Integrated disaster-risk reduction initiatives in government programmes, effective dissemination structures, natural resource-management projects and communityparticipation programmes are only a few examples of actions that will contribute to the development of effective early warning services, and the subsequent response to and adoption of the advices/services strategies by the people most affected. The effective distribution of the most useful early warning services to the end-user, who needs it at the right time through the best governing structures, may significantly improve decision making in the agricultural, food security and other water-sensitive sectors. Developed disaster-risk policies for extension and farmers as well as other disaster prone sectors should encourage self-reliance and the sustainable use of natural resources, and will reduce the need for government intervention. The SCF producers (e.g. the South African Weather Service (SAWS)) have issued new knowledge to intermediaries for some years now, and it is important to determine whether this knowledge has been used in services, and if so whether these services were applied effectively in coping with disaster-risks and in disaster v reduction initiatives and programmes. This study for that reason also intends to do an evaluation of the knowledge communication processes between forecasters, and intermediaries at national and provincial government levels. It therefore, aims to assess and evaluate the current knowledge communication structures within the national agricultural sector, seeking to improve disaster-risk reduction through effective early warning services. A boundary organisation is an organization which crosses the boundary between science, politics and end-users as they draw on the interests and knowledge of agencies on both sides to facilitate evidence base and socially beneficial policies and programmes. Reducing uncertainty in SCF is potentially of enormous economic value especially to the rural communities. The potential for climate science to deliver reduction in total SCF uncertainty is associated entirely with the contributions from internal variability and model uncertainty. The understanding of the limitations of the SCFs as a result of uncertainties is very important for decision making and to end-users during planning. Disappointing, however, is that several studies have shown a fairly narrow group of potential users actually receive SCFs, with an even a smaller number that makes use of these forecasts In meeting the objectives of the study the methodology to be followed is based on knowledge communication. For that reason two types of questionnaires were drafted. Open and closed questionnaires comprehensively review the knowledge, understanding, interpretation of SCFs and in early warning services distribution channels. These questionnaires were administered among the SCF producers and intermediaries and results analysed. Lastly the availability of useful SCFs knowledge has important implications for agricultural production and food security. Reliable and accurate climate service, as one of the elements of early warning services, will be discussed since they may be used to improve agricultural practices such as crop diversification, time of planting vi and changes in cultivation practices. It was clear from the conclusions of the study that critical elements of early warning services need to receive focused attention such as the SCF knowledge feedback programme should be improved by both seasonal climate producers and intermediaries, together with established structures through which reliable, accurate and timely early warning services can be disseminated. Also the relevant dissemination channels of SCFs are critical to the success of effective implementation of early warning services including the educating and training of farming communities. The boundary organisation and early warning structures are important in effective implementation of risk reduction measures within the agricultural sector and thus need to be prioritised. Enhancing the understandability and interpretability of SCF knowledge by intermediaries will assist in improving action needed to respond to SCFs. Multiple media used by both SCF producers and intermediaries in disseminating of SCFs should be accessible by all users and end-users. The Government should ensure that farming communities are educated, trained and well equipped to respond to risks from natural hazards.

M.Sc., Faculty of Science, University of the Witwatersrand, 2011 / Biogenic volatile organic compounds (BVOCs), in the presence of nitrogen oxide gases (NOx), play a role in the production of tropospheric ozone (O3) which is an effective greenhouse gas and is hazardous to human health (Haagen-Smit, 1952, Chameides et al, 1988, Atkinson, 2000, Kanakidou et al, 2004). Isoprene is a single BVOC that accounts for over 50% of all emitted BVOCs. Isoprene emissions are species specific and vary according to temperature, light and leaf area index. Climate change studies predict that the geographic distribution of species, temperature ranges, light intensity and leaf area index will shift, thus altering future isoprene emissions. Several attempts to model BVOC emissions have been undertaken in an effort to quantify BVOC emission rates and the impact on ozone formation. The most widely used and empirically tested emission algorithms to date were developed by Guenther et al (1993) and are incorporated into the emission model Model of Emissions of Gases and Aerosols from Nature (MEGAN). MEGAN is used in this study to model isoprene emission rates over southern Africa under current and future climate conditions. Current and future climate conditions are taken from the regional climate model, Conformal-Cubic Atmospheric Model (C-CAM), which has been shown to simulate current climate well for the region. Emissions were modelled for January and July only, to represent summer and winter conditions. January isoprene emission rates for the current climate range from 0 to 1.41 gm-2month-1 and total 0.938 Tg of isoprene for the study domain. The highest emission rates are caused by combinations of driving variables which are: high temperature only; high temperature and high leaf area index; high emission factor and high leaf area index. Emission rates effectively shut down in July due to low temperatures and low leaf area index. July emission rates range from 0 to 0.61 gm-2month-1 and total 0.208 Tg of isoprene. Temperature is shown to cause the greatest variation in isoprene emission rates, and thus future scenarios represent an increase in temperature only. The spatial distribution of future emission rates does not shift when compared to current emission rates, but does show an increase in magnitude. Future emission totals for January increase iv by 34% to 1.259 Tg of isoprene and the July emission total increases by 38% to 0.289 Tg of isoprene. Future emission rates responded to temperature as expected, increasing in magnitude, rate of change and range of temperature over which the greatest rate of change occurs. Three areas demonstrating the highest increase in emission rates and highest future emission rates were identified. As temperature was the only variable altered in future scenarios, these areas can be deemed as areas most sensitive to changes in temperature. These areas are situated near the Angola-Namibia border, the Northern Interior of South Africa and the low-lying areas of Mozambique.

"The main objective of this study is to examine the influence of global SSTAs [sea surface temperature anomalies] on rainfall over eastern Africa (Fig. 1) using Florida State University T21 Global Spectral Model (FSUT21GSM) during the southern hemisphere summer of 1982 (wet year) and 1983 (dry year) (Fig. 2)"--Leaf 3. / Typescript. / "Summer Semester, 1991." / "Submitted to the Department of Meteorology in partial fulfillment of the requirements for the degree of Master of Science." / Advisor: T. N. Krishnamurti, Professor Directing Thesis. / Includes bibliographical references.

INTRODUÇÃO: A urbanização em bacias hidrográficas contribui para a eutrofização antrópica dos seus corpos d´água, propiciando proliferações de algas tóxicas como as cianobactérias. Existe um padrão característico de sazonalidade nas florações de algas e comunidades de cianobactérias, embora estas algas possam estar presentes ou mesmo dominantes, na maior parte do ano, trazendo problemas práticos associados à elevada biomassa de cianobactérias e potenciais ameaças à saúde pelo aumento de toxinas. A hipótese desta tese é de que as variações do tempo e do clima podem influenciar a qualidade da água de abastecimento ao propiciar florações das algas tóxicas, cianobactérias, que geram toxinas dificilmente filtradas pelos mecanismos comuns, gerando um problema de saúde pública que pode ser agravado com as mudanças climáticas conjuntamente o fenômeno de urbanização crescente nos países de economia emergente. OBJETIVO: O objetivo deste estudo foi investigar qual a influência do tempo e do clima na qualidade da água de abastecimento público de bacias urbanizadas através do indicador de algas tóxicas chamadas cianobactérias. MATERIAL E MÉTODOS: Para tanto investigou-se em primeiro lugar qual o contexto das proliferações de cianobactérias em reservatório de abastecimento público e suas consequências bem como qual o estado da arte sobre a qualidade da água de reservatórios eutrofizados em bacias urbanizadas, foi elaborado um mapeamento bibliográfico para saber qual a extensão do problema e do que se sabe a respeito. E, por fim, correlacionou-se a influência do tempo e do clima na qualidade da água para abastecimento no caso da bacia urbanizada da Represa Guarapiranga, localizada ao sul da Cidade de São Paulo, com vistas à previsibilidade e prevenção do fenômeno das florações das cianobactérias. RESULTADOS E DISCUSSÃO: Chegando-se a conclusão de que a pressão antrópica e o uso do solo são um fator determinante para a eutrofização de reservatórios de abastecimento e que, por tanto, bacias hidrológicas ocupadas pelo espraiamento urbano são particularmente propensas a apresentar reservatórios de água contaminados com algas toxicas, ao mesmo tempo que são as mais visadas para abastecer a população em seu entorno. O mapeamento bibliográfico mostrou que a proliferação de cianotoxinas em reservatórios eutrofizados é prevalente em diferentes latitudes e climas. A modelagem de correlação teve sucesso em explicar de 16% à 30% das florações na Guarapiranga de acordo com episódios de Irradiação e de precipitação pluviométrica, sendo resultados coerentes com a literatura, embora sejam baixo para gerar um modelo preditivo. CONSIDERAÇÕES FINAIS: A pressão antrópica da urbanização de bacias hidrográficas sem planejamento ou infra-estrura sanitária se mostrou uma questão de Saúde Pública e Saúde Urbana. As florações de cianobactérias se apresentaram como fenômenos presentes em diferentes latitudes, climas e graus de organização do espaço, mostrando assim serem uma questão global de saúde pública. A modelagem para o caso de São Paulo resultou em valores de explicação insuficientes para gerar um modelo preditivo do fenômeno das florações, evidenciando o sistema complexo de interação ambiente-ocupação humana-uso do solo- clima, exigindo assim que sejam acrescentadas demais variáveis ao modelo. / INTRODUCTION: Urbanization in hydrographic basins contributes to the anthropic eutrophication of their water bodies, propitiating toxic algae proliferation such as cyanobacterias. There is a characteristic pattern of seasonality in algae blooms and cyanobacteria communities, although theses algae may be present or even dominant during most part of the year. They cause practical problems associated with high biomass volumes, and potential health threats by the rise of toxins. This thesis\' hypothesis is that weather and climate variations can influence the quality of drinking water supply, because toxins are hardly filtered by ordinary mechanisms. The problem can be aggravated by climate change conjointly with the rapid widespread of urbanization in low and middle income countries. OBJECTIVE: This study\'s aim was to investigate the influence of weather and climate variables on the quality of water from the public drinking water supply system of an urbanized watershed through the indicator of toxic algae - denominated cyanobacterias. MATERIALS AND METHODS: First, the cyanobacterias\' blooms in eutrophic reservoir and its\' consequences, was studied by literature review and by an exploratory analysis of monthy weather varables and cyanobacterias data. Secondly, a bibliographical mapping review was drafted in order to know the extension of the problem and what is known regarding it. Finally, data of weather and climate were correlated with the quality of supple water of the, Guarapiranga reservoir, located on the south of São Paulo metropolitan area, acknowledging predictability and prevention of the phenomenon of cyanobacteria bloom. FINDINGS AND DISCUSSION: The conclusion was that the anthropic pressure and land use are determinant factors to the eutrophication of supply reservoir and, therefore, hydrological basins occupied by urban sprawling are particularly at risk of presenting water reservoirs contaminated with toxic algae. They are the most targeted to supply water to their neighbor population. The bibliographic mapping showed that the proliferation of cyanotoxins in eutrophized reservoirs is prevalent in different latitudes and climates. The correlation modeling was successful in explaining 16% to 30% of blooms in Guarapiranga according to episodes of irradiation and low precipitation, matching results found in literature, although they are low for the creation of a predicative model. FINAL CONSIDERATIONS: The anthropic pressure of urbanization on hydrographic basins without planning or sanitary infrastructure guidelines was shown to be a matter of public and urban health. Cyanobacterias\' blooms was shown to be a phenomena present in different latitudes, climates and degrees of space organization, proving to be a matter of global public health. The modeling for the case of São Paulo has resulted in insufficient explanation values to generate a predictive model of the phenomena of flowering, indicating the complex interaction system involving environment, human occupation, land use and climate, and demanding that more variables be acknowledged in the model.

O presente trabalho foi desenvolvido em áreas florestais naturais e implantadas de Florestas Estacionais Semideciduais remanescentes do planalto paulista com o objetivo de estudar a periodic idade de crescimento, fenologia e atividade cambial. A pesquisa visa determinar a idade e o crescimento de 23 espécies arbóreas tropicais e subtropicais, contribuindo, desta forma, com a aquisição de conhecimentos científicos básicos sobre a biologia e a ecologia do crescimento das mesmas. A compreensão da dinâmica das populações florestais e o comportamento de crescimento das suas espécies foram obtidos a partir do acompanhamento mensal da periodicidade de crescimento através da implantação de faixas dendrométricas permanentes nos troncos das árvores e observações dos estágios fenológicos (folhas, brotamento, floração e frutificação), avaliados mensalmente durante o período de janeiro de 2000 a outubro de 2001 em relação às variações climáticas. A determinação da idade e taxa de crescimento das árvores foram obtidas através da contagem e mensuração da largura dos anéis de crescimento a partir de "baguetas" coletadas com auxílio da sonda de Pressler, na altura do DAP. Os resultados deste trabalho permitiram concluir que as variações das taxas de crescimento em circunferência do tronco das árvores estão estreitamente relacionadas à precipitação e a disponibilidade de água no solo na estação chuvosa e a ocorrência de um período de seca com redução e/ou cessação da atividade cambial. Da mesma forma, os estágios fenológicos estão relacionados com fatores abióticos como o clima e, em especial, às variações de precipitação entre as estações seca e úmida. As informações sobre a influência de fatores ambientais na taxa de crescimento das espécies arbóreas permitirão a adoção de medidas científicas que visem a preservação da biodiversidade desses ecossistemas frágeis e constantemente ameaçados. / This paper was developed in natural and implanted forest areas of remaining Semidecidual Stately Forests in Sao Paulo plains, with the aim of stud ying the periodicity of growth, the phenology and its changing activity. The research seeks determining the age and growth of 23 tropical and semitropical arboreal species, thus contributing with the gathering of basic scientific knowledge on the biology and the ecology of their growth. The understanding on the forests’ populations’ dynamics and the behavior of their growth were obtained with a monthly observation through the inserting of permanent dendometric strips into the trees trunks and through the phonological stages analysis (leaves, sprouting, blooming and fruiting), evaluated from January 2000 to October 2001 because of the weather variations. The age and growth rate determination was obtained counting and measuring the growth rings starting with wood samples collected with the help of a Pressler probe, at the DAP height. The results of this paper led to the conclusion that the variations on the perimeter of the trunk growth rate are closely related to the rainfall and water availability in the soil under the rainy season and the occurrence of a drought period with reduction and/or changing activity cessation. Likewise, the phenological stages are related to abiotic factors like weather and, especially, to rainfall variations between the dry and humid seasons. The information on the influence of environmental factors on the growth rate of arboreal species will facilitate the adoption of scientific measures seeking the preservation of the biodiversity of these ecosystems so fragile and constantly under threat

O registro da temperatura terrestre é um indicador fundamental nas análises de mudanças do clima global. A presente investigação tratou da verificação e quantificação dos efeitos de heterogeneidades (erros) em séries da temperatura do ar obtidas em estação climatológica localizada em Itirapina, SP, Brasil. As principais causas de heterogeneidades estudadas foram: mudanças dos horários de observação e cálculos da temperatura média diária; mudanças dos tipos de instrumentos utilizados (convencionais e automáticos) e mudanças nos abrigos meteorológicos. A metodologia aplicada consistiu em comparar, em diferentes escalas temporais, várias séries de temperatura do ar em relação a uma série de referência, assumida como mais confiável. As diferenças obtidas, em termos de desvios, resultaram em valores nas seguintes ordens de grandeza, de acordo com cada escala: 10,0ºC na escala das medições horárias; 5,0ºC na escala das médias diárias; 2,0ºC, na escala mensal; 1,0ºC na escala anual; e 1,5ºC na escala de normal climatológica (30 anos) de exibição dos valores médios da temperatura do ar. Conclui-se que em escalas reduzidas (horárias e diárias) existem erros de alta magnitude de variação, porém de baixa frequência de ocorrência. Com o aumento da escala, a magnitude dos desvios diminui. As causas de heterogeneidades, de acordo com os desvios observados, ficam classificadas, na ordem de menor para a maior intensidade de influência: mudanças dos abrigos; mudanças dos cálculos das médias diárias; e mudanças dos instrumentos. No contexto da discussão do aquecimento global, na ordem de 0,6ºC no último século, a ocorrência de erros e incertezas de mesma ou maior magnitude pode comprometer o uso da temperatura do ar como uma evidência confiável de mudanças do clima, uma vez que mudanças não-climáticas interferem significativamente nas medições. O uso da evidência é discutido no contexto da interação entre a Ciência, Política, Mídia e Economia. Foi identificado que, neste âmbito externo ao meio científico, as incertezas são diminuídas e ignoradas, tanto devido ao processo de simplificação da informação para sua difusão, quanto devido a interesses que norteiam a manipulação intencional e tendenciosa do tema. Devido à disputa de diferentes interesses, foi feita uma breve discussão de alguns aspectos controversos, permeando a atuação de cientistas céticos à crença da contribuição humana significativa nas mudanças climáticas. / The instrumental temperature record is a key indicator in the analysis of global climate change. This research dealt with the verification and quantification of the effects of heterogeneities (errors) in air temperature series obtained from a climatological station located in Itirapina, SP, Brazil. The main causes of heterogeneity studied were: changes on the times of observation and on the daily mean air temperature calculation; changes on the types of instruments (conventional and automatic); and changes in thermometer screens. The methodology consisted of comparing, at different time scales, several series of air temperature series in relation to a reference series, assumed to be more reliable. The differences obtained, in terms of deviations, resulted in the following orders of magnitude, according to each scale: 10.0ºC in the range of hourly measurements, 5.0ºC in the range of daily mean, 2.0°C in monthly scale, 1.0°C in the annual scale and 1.5°C in the climatological normal scale (30 years). It follows that at small scales (hourly and daily) exist errors of high magnitude of change, but low frequency of occurrence. With increasing scale, the magnitude of the deviations decreases. The causes of heterogeneity, according to the observed deviations, are ranked in order of lowest to highest extent of influence: changes on screens, changes on daily mean air temperature calculation, and changes of the instruments. In the context of the discussion of global warming, on the order of 0.6ºC over the last century, the occurrence of errors and uncertainties in same or greater magnitude can compromise the use of air temperature as a reliable evidence of climate changes, since non-climatic changes significantly interfere the measurements. The use of evidence is discussed in the context of the interaction between Science, Politics, Media and Economics. It was identified that, outside the scientific environment context, the uncertainties are reduced and neglected, both due to the simplification process for the information dissemination, as due to concerns that guide the intentional and biased manipulation on the subject. Due to the competition of different interests, there was held a brief discussion of some controversial aspects, permeating the work of skeptical scientists on the belief of the significant human contribution to the climate change.

Esta pesquisa apresenta uma análise da distribuição espacial e variabilidade da precipitação pluviométrica na bacia do rio Piquiri-PR, baseando-se na teoria sistêmica e nas condições de troca de energia e matéria em uma bacia hidrográfica. Analisaram-se as condições pluviométricas para o período de 1976-2010 com dados de 73 postos pluviométricos do Instituto das Águas do Paraná. Verificando a distribuição e a variabilidade espaço-temporal da precipitação pluviométrica por meio de mapas de isoietas gerados a partir da interpolação dos dados pluviométricos na bacia do rio Piquiri, percebeu-se que os sistemas atmosféricos e o relevo participam ativamente na distribuição anual, sazonal e mensal da precipitação. Entre as cotas altimétricas de 400 a 900 metros o efeito do relevo potencializa o acréscimo de precipitação média anual, indicando singularidades no que diz respeito à variabilidade espacial da chuva. Por meio da metodologia dos anos-padrão determinaram-se os anos chuvosos, secos e habituais, e de acordo com a distribuição característica mensal da chuva escolheu-se os anos de 1983, 1978 e 2001 para o estudo detalhado da variabilidade pluviométrica. Notou-se que as variações espaciais e temporais diferenciam-se entre o sul e sudeste em relação ao norte e noroeste da bacia, o mais chuvoso e o menos chuvoso respectivamente. A disponibilidade hídrica analisada através do balanço hídrico climatológico de Thornthwaite e Mather (1955) mostra variações mensais nos excedentes e nas deficiências hídricas da bacia, sendo março o mês com maior deficiência enquanto maio e outubro os meses de maior excedente hídrico. / This research presents an analysis of spatial distribution and variability of rainfall in the watershed Piquiri-PR, based on the systemic theory and conditions exchange energy and matter in a drainage basin. It was analyzed the rainfall conditions to the period 1976-2010 with data 73 gauge stations of Instituto das Aguas do Paraná. Checking the distribution and spatio-temporal variability of rainfall with maps of isohyets generated from the interpolation of rainfall data in the drainage basin Piquiri, it was realized that atmospheric systems and the relief actively participate in the precipitation distribution annual, seasonal and monthly. Between altimetric elevations of 400-900 meters the relief effect potentiates the increase average annual rainfall, indicating singularities to the rainfall spatial variability. Through of methodology years-pattern were determined the wet years, dry and normal, and according to the characteristic distribution of monthly rain was chosen the years 1983, 1978 and 2001 to the detailed study of rainfall variability. It was observed that the spatial and temporal variations differentiate between the south and southeast compared with the north and northwest of the drainage basin, the most rainy and less rainy, respectively. The water availability analyzed by water balance climatology Thornthwaite and Mathers (1955) shows monthly variations in the excess and deficiencies of water of drainage basin, March being the month with the highest deficiency while May and October the months of highest water excess.

O clima apresenta uma importância indiscutível, constituindo-se num dos mais relevantes elementos da biosfera, desta forma imprescindível o conhecimento minucioso de sua dinâmica, bem como de sua interação com os outros elementos do ambiente. Optou-se pelo estudo de uma \"bacia hidrográfica\" pelas facilidades de análise que a mesma oferece, pois por se tratar de uma unidade bem delimitada, todos os processos geológicos, geomorfológicos, hidrológicos, pedológicos, climatológicos, entre outros, ocorrem, em seu limite natural. Para tanto, selecionou-se a Bacia do Ribeirão do Lobo, por apresentar uma consistência de dados meteorológicos fundamentais para este estudo, e por abranger uma área de foco de muitas pesquisas em diversas áreas do conhecimento. Assim, uma das metas desta pesquisa foi apresentar informações climatológicas que subsidiarão a compreensão dos fenômenos interligados em outras áreas. A concepção climática elaborada por SORRE (1951) e na análise rítmica preconizada por MONTEIRO (1971) foram os conceitos norteadores desta pesquisa, entretanto, numa primeira etapa efetuou-se uma abordagem climática tradicional, utilizando-se de estatística e de computação, para definir as tendências ao longo da referida bacia hidrográfica. Assim, sob a temática do clima, foram analisados quatro episódios representativos, descrevendo o comportamento da circulação atmosférica e as repercussões nos elementos climáticos. / The climate presents an unquestionable importance, being constituted in one of the most important elements of the biosphere, thus becoming indispensable the meticulous knowledge of its dynamics, as well as its interaction with the other elements ofthe atmosphere. The study of a hydrographic basin was opted due to its easiness of analysis therefore for being a well delimited physical unit, all the geological processes, geomorphologic, hidrologic, pedologic, climatological, amog others, occur in its natural boundary. For this purpose, the Wolf River System was selected, by presenting a consistence of fundamental meteorological data for this study, and for comprising a focus area of many researches in several areas of knowledge. Thus, one of the goals of this research was to present climatological information that will subsidize the understanding of the interlinked phenomena in other areas. The climactic conception elaborated by SORRE (1951) and in the rhythmic analysis extolled by MONTEIRO (1971) were the guideline of this research, however, in a first stage it occurred a traditional climactic approach, making use of the statistics and of the computation, to define the tendencies along referred hydrographic basin. So, under the optics dynamics of the climate, four representative episodes were analyzed, describing the behavior of the atmospheric circulation and the repercussions in the climactic elements.

O presente trabalho analisou o ritmo climático da cidade de Descalvado - SP, por meio de dois episódios representativos do fato climático (de inverno e de primavera), bem como o comportamento térmico no interior de duas casas populares ocupadas, situadas na área urbana do município. Utilizou-se estação automática (CR10X - Campbell Scientific Inc.) que possibilitou a aquisição e o armazenamento dos dados meteorológicos, vinculando estes dados climáticos ao sistema de circulação atmosférica secundária. Dentro da abordagem Dinâmica do Clima, utilizou-se os conceitos de tipos de tempo afeito ao comportamento térmico das casas ocupadas. Os limites da zona de conforto propostos por GIVONI (1992) foram utilizados como referencial na análise do comportamento térmico das casas ocupadas. Os resultados demonstraram que as duas residências apresentaram comportamento térmico semelhante durante as possíveis situações de estresse de calor e frio. Conclui-se que, apesar de se tratar, do ponto de vista econômico, de moradias de baixo custo de construção, são casas que apresentaram adequado desempenho térmico. / The present work analyze the climatic rhythm Descalvado - SP, by using representative episodes of the climatic (winter and spring), as well as the thermal behavior of two occupied popular houses indoor, located in urban area of municipal district. Automatic station used (CR10X - Campbell Scientific Inc.) made possible acquisition and storage of meteorological data, correlating climatic data to the secondary atmospheric circulation system. Dynamic approach of Climate was used the concepts of Types of Time for obtaining thermal behavior of the occupied houses. Givoni\'s limits of comfort zone (1992) was used a reference in analysis of house\'s thermal performance. Results demonstrated that the two occupied houses presented similar thermal behavior during possible situation of heat and cold stresses. For conclusion, under economical point of view, although treating of low cost construction homes, they are houses that presented appropriate thermal performance.

Dentro da abordagem dinâmica do clima, o presente trabalho visou a estudar a configuração espaço-temporal do campo térmico da cidade de São Carlos-SP, dentro de suas variações diurnas e das condições impostas pelos diferentes tipos de tempo, com o intuito de caracterizá-lo quanto à sua intensidade e identificar a formação de ilhas urbanas de calor no período de inverno. Para tanto foram utilizados dados climáticos registrados por três estações automáticas localizadas em pontos distintos da malha urbana, imagens do satélite GOES e cartas de pressão atmosféricas reduzidas ao nível do mar. De acordo com os resultados obtidos, a ilha de calor urbana é mais pronunciada na fase de domínio da massa Polar Atlântica, sendo que as maiores diferenças térmicas foram observadas durante o período diurno. Sob as condições impostas pela massa Polar Atlântica as diferenças observadas entre os campos térmicos da região mais próxima do centro urbano de São Carlos e as duas regiões mais afastadas ficaram entre 2,0 e 3,0°C. / On the dynamical approach of climate, the present work aimed the study the time-space configuration of the thermal filed of the city of São Carlos-SP, within the diurnal variations and the conditions imposed by the different weather types, in order to characterize its intensity and identify the formation of urban heat islands during winter. Thus climatic data registered by three automatic stations located in distinct points of the urban network, GOES satellite images and atmospheric pressure letters at sea level were used. According to the obtained results, the urban heat island is more pronounced in the activity of Polar Atlantic air mass, with the biggest thermal differences being observed during the diurnal period. Under the conditions imposed by the Polar Atlantic mass the observed differences between the thermal fields of the nearest downtown region of São Carlos and the two distant regions were between 2.0 and 3.0 ºC.