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Accurate simulation of energy, water, and carbon fluxes exchanging between the land surface and the atmosphere is beneficial for improving terrestrial ecohydrological and climate predictions. We systematically assessed the Noah land surface model (LSM) with mutiparameterization options (Noah-MP) in simulating these fluxes and associated variations in terrestrial water storage (TWS) and snow cover fraction (SCF) against various reference products over 18 United States Geological Survey two-digital hydrological unit code regions of the continental United States (CONUS). In general, Noah-MP captures better the observed seasonal and interregional variability of net radiation, SCF, and runoff than other variables. With a dynamic vegetation model, it overestimates gross primary productivity by 40% and evapotranspiration (ET) by 22% over the whole CONUS domain; however, with a prescribed climatology of leaf area index, it greatly improves ET simulation with relative bias dropping to 4%. It accurately simulates regional TWS dynamics in most regions except those with large lakes or severely affected by irrigation and/or impoundments. Incorporating the lake water storage variations into the modeled TWS variations largely reduces the TWS simulation bias more obviously over the Great Lakes with model efficiency increasing from 0.18 to 0.76. Noah-MP simulates runoff well in most regions except an obvious overestimation (underestimation) in the Rio Grande and Lower Colorado (New England). Compared with North American Land Data Assimilation System Phase 2 (NLDAS-2) LSMs, Noah-MP shows a better ability to simulate runoff and a comparable skill in simulating R-n but a worse skill in simulating ET over most regions. This study suggests that future model developments should focus on improving the representations of vegetation dynamics, lake water storage dynamics, and human activities including irrigation and impoundments.

The meridional temperature gradient between middle and high latitudes is decreasing due to Arctic amplification, which enhances the warming in the Arctic region. This change in temperature is also influencing the circulation and the horizontal energy fluxes between the mid latitudes and the Arctic, which itself might influence the Arctic additionally. The horizontal energy flux, to our best knowledge, has never been analyzed using the up-to-date method called self-organizing map (SOM). The SOM is a simple unsupervised neural network that is used to extract patterns of high-dimensional data and presents the patterns in a two dimensional lattice, where similar (more different) patterns are closer together (farther apart) within the lattice. An advantage of using the SOM is that there are no underlying linear assumptions like in other methods that characterize the circulation, such as the Arctic Oscillation or the North Atlantic Oscillation index. The SOM has been used in this work to extract and analyze horizontal heat flux patterns from reanalysis data and climate model data. Using the SOM method, it was possible to find distinct horizontal heat flux patterns into the Arctic, that have been combined into heat flux pathways. The SOM made it possible to characterize the pathways' change in occurrence frequency throughout the last thirty years and the change between present-day climate model simulations and climate projections with increased greenhouse gas concentrations. Using reanalysis data, three distinct patterns have been extracted, which all show different features. They are named according to the main pathway the horizontal heat flux takes to reach the Arctic: the Atlantic pathway, the Pacific pathway, and the continental pathway. For the reanalysis data, it is shown that the Atlantic pathway, which is connected with positive temperature anomalies in the central Arctic, has become more frequent during the last three decades, while the Pacific pathway, that is connected to negative temperature anomalies around Svalbard, has become less frequent. This suggests that the circulation, which is connected to the temperature in the Arctic, is changing. The trends for the occurrence frequencies of the SOM horizontal heat flux pathways have, to our best knowledge, never been analyzed prior to this work. With respect to climate model results, the three distinct patterns were also identified in climate simulations of the second half of the twentieth century and climate projections of the second half of the twenty-first century from eight models. This demonstrates that these three pathways are an inherent part of the atmosphere. In comparison with the reanalysis data, the climate models show much stronger occurrence frequencies for the continental pathway. The reanalysis data of the continental pathway does not show such high occurrence frequencies. However, the multi model mean shows a clear decrease in these occurrence frequencies of the continental pathway between the present-day climate simulation and the climate projection with increased greenhouse gas concentrations. The continental pathway is mostly connected to strong zonal fluxes while there are only small meridional transports over Siberia or North America. This suggests that the fluxes become more meridional with an enhanced warming and thus increase the heat flux into the Arctic, which might influence the surface air temperature.:Bibliographische Beschreibung Bibliographic Description Acronyms 1. Introduction: Arctic Amplification, Circulation and Transport 1.1. Arctic Amplification 1.2. The (AC)3 project 1.3. Overview of General Circulation in Mid and High Latitudes 1.3.1. Drivers of the general circulation 1.3.2. Circulation impacts on high and mid latitudes 1.3.3. Atmospheric energy transport into the Arctic 1.4. Overview of the Thesis 2. The Self-organizing Map 2.1. Mathematical Description 2.2. SOM Parameters and their Effect on Clustering Meteorological Data 2.2.1. Map size 2.2.2. Neighborhood function 2.2.3. Iterations 2.2.4. Learning rate 2.2.5. Summary of the effect of learning parameters 2.3. Limits of SOM 2.4. Application of SOM in Atmospheric Sciences 2.5. Comparison with the K-Means Clustering Algorithm 2.6. A Practical Guide to SOM 3. Clustering of Atmospheric Energy Transport within ERA-Interim 3.1. Data and Method 3.1.1. ERA-Interim data 3.1.2. Analysis method 3.2. Results 3.2.1. Heat transport SOM 3.2.2. Temperature anomaly composites related to transport pathways 3.2.3. Mean meridional heat transport 3.2.4. Trend of transport pathways 3.2.5. Two-meter temperature trends 3.3. Discussion 3.4. Summary of ERA-Interim Analysis 4. Comparison of Flux Pathways in CMIP5 Model Analysis 4.1. Methods and Data 4.1.1. CMIP5 model data 4.1.2. Analysis using the SOM method 4.2. Results 4.2.1. Historical patterns 4.2.2. RCP8.5 patterns 4.2.3. Mean pathway occurrence frequencies 4.2.4. Pathway occurrence frequency trends during the historical and future time intervals 4.3. Discussion of CMIP5 Analysis 5. Summary and Conclusion of the Horizontal Energy Flux SOM Analysis References A. Appendix: ERA-Interim Self-Organizing Map Analysis B. Appendix: CMIP5 Self-Organizing Map Results Acknowledgments Curriculum Vitae Affirmation / Der meridionale Temperaturgradient zwischen mittleren und hohen Breiten nimmt aufgrund der arktischen Verstärkung ab. Diese Temperaturänderung beeinflusst auch die Zirkulation und die horizontalen Energieflüsse zwischen den mittleren Breiten und der Arktis, was die Arktis selbst zusätzlich beeinflussen könnte. Der horizontale Energietransport wurde, unserem bestem Wissen nach, nie mit der aktuellen Methode namens Self-Organizing Map (SOM) analysiert. Die SOM ist ein einfaches unüberwachtes neuronales Netzwerk, das zum Extrahieren von Mustern hoch dimensionaler Daten verwendet wird und die Muster in einem zweidimensionalen Gitter darstellt, in dem ähnliche (unterschiedliche) Muster innerhalb des Gitters näher beieinander (weiter voneinander entfernt) liegen. Ein Vorteil der SOM besteht darin, dass keine linearen Annahmen wie bei anderen Methoden vorliegen, die die Zirkulation charakterisieren, wie z. B. die Arktische Oszillation oder der Nordatlantische Oszillationsindex. Die SOM wurde im Rahmen dieser Arbeit verwendet, um horizontale Wärmetransportmuster aus Reanalysedaten und Klimamodelldaten zu extrahieren und zu analysieren. Mit der SOM-Methode konnten unterschiedliche horizontale Muster des Wärmetransports in die Arktis identifiziert werden, welche wiederum zu Pfaden zusammengefasst wurden. Die SOM ermöglichte es, die Veränderung der Auftrittshäufigkeit der Pfade in den letzten dreißig Jahren und die Veränderung der Muster zwischen einer Simulation des heutigen Zustandes und einer Klimaprojektion mit erhöhten Treibhausgaskonzentrationen zu charakterisieren. Unter Verwendung von Reanalysedaten konnten drei unterschiedliche Pfade extrahiert werden, die alle unterschiedliche Merkmale aufweisen. Sie wurden nach dem jeweiligen Hauptpfad benannt, den der horizontale Wärmetransport vollzieht, um in die Arktis zu gelangen: der Atlantikpfad, der Pazifikpfad und der Kontinentalpfad. Für die Reanalysedaten konnte gezeigt werden, dass die Auftretenshäufigkeit des Atlantikpfads, der mit positiven Temperaturanomalien in der Zentralarktis verbunden ist, in den letzten drei Jahrzehnten gestiegen ist. Demgegenüber ist die Auftretenshäufigkeit des pazifischen Pfads, der mit negativen Temperaturanomalien um Spitzbergen verbunden ist, in den letzten drei Jahrzehnten gesunken. Dies deutet darauf hin, dass sich die Zirkulation, die mit der Temperatur in der Arktis verbunden ist, ändert. Die Trends für die Auftrittshäufigkeiten der horizontalen SOM-Wärmetransportpfade wurden, nach bestem Wissen, vor dieser Arbeit noch nie analysiert. Auswertungen basierend auf acht Klimamodellen haben die drei unterschiedlichen Muster sowohl in Klimasimulationen für die zweite Hälfte des zwanzigsten Jahrhunderts, als auch in Klimaprojektionen der zweiten Hälfte des einundzwanzigsten Jahrhunderts gefunden. Dies zeigt, dass diese drei Pfade der Atmosphäre inhärent sind. Im Vergleich zu den Reanalysedaten zeigen die Klimamodelle viel stärkere Auftrittshäufigkeiten für den Kontinentalpfad. Die Reanalysedaten des Kontinentalpfads weisen keine hohen Auftrittshäufigkeiten auf. Der Multi-Modell-Mittelwert zeigt jedoch eine deutliche Abnahme dieser Auftrittshäufigkeiten des Kontinentalpfads zwischen der Simulation des heutigen Zustands und der Projektion mit erhöhten Treibhausgaskonzentrationen. Der Kontinentalpfad ist meist mit starken zonalen Transporten verbunden, während nur kleine meridionale Transporte über Sibirien oder Nordamerika erfolgen. Dies deutet darauf hin, dass mit zunehmender Erwärmung die Flüsse meridionaler werden sowie den Wärmetransport in die Arktis erhöhen und somit die Lufttemperatur in Bodennähe beeinflussen können.:Bibliographische Beschreibung Bibliographic Description Acronyms 1. Introduction: Arctic Amplification, Circulation and Transport 1.1. Arctic Amplification 1.2. The (AC)3 project 1.3. Overview of General Circulation in Mid and High Latitudes 1.3.1. Drivers of the general circulation 1.3.2. Circulation impacts on high and mid latitudes 1.3.3. Atmospheric energy transport into the Arctic 1.4. Overview of the Thesis 2. The Self-organizing Map 2.1. Mathematical Description 2.2. SOM Parameters and their Effect on Clustering Meteorological Data 2.2.1. Map size 2.2.2. Neighborhood function 2.2.3. Iterations 2.2.4. Learning rate 2.2.5. Summary of the effect of learning parameters 2.3. Limits of SOM 2.4. Application of SOM in Atmospheric Sciences 2.5. Comparison with the K-Means Clustering Algorithm 2.6. A Practical Guide to SOM 3. Clustering of Atmospheric Energy Transport within ERA-Interim 3.1. Data and Method 3.1.1. ERA-Interim data 3.1.2. Analysis method 3.2. Results 3.2.1. Heat transport SOM 3.2.2. Temperature anomaly composites related to transport pathways 3.2.3. Mean meridional heat transport 3.2.4. Trend of transport pathways 3.2.5. Two-meter temperature trends 3.3. Discussion 3.4. Summary of ERA-Interim Analysis 4. Comparison of Flux Pathways in CMIP5 Model Analysis 4.1. Methods and Data 4.1.1. CMIP5 model data 4.1.2. Analysis using the SOM method 4.2. Results 4.2.1. Historical patterns 4.2.2. RCP8.5 patterns 4.2.3. Mean pathway occurrence frequencies 4.2.4. Pathway occurrence frequency trends during the historical and future time intervals 4.3. Discussion of CMIP5 Analysis 5. Summary and Conclusion of the Horizontal Energy Flux SOM Analysis References A. Appendix: ERA-Interim Self-Organizing Map Analysis B. Appendix: CMIP5 Self-Organizing Map Results Acknowledgments Curriculum Vitae Affirmation

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A vegetação tropical é uma das maiores fontes de evapotranspiração e desempenha um papel importante na dinâmica climática global e nos processos de produtividade primária de ecossistemas terrestres, uma vez que se encontra diretamente ligada aos processos de transferência de massa e energia. Objetivou-se nesta tese de doutorado avaliar a acurácia das estimativas de ET baseadas em modelos de sensoriamento remoto quando comparadas a medições pontuais obtidas a partir de torres de fluxo e a partir do fechamento do balanço hídrico a médio e longo prazo. Foram selecionados dois modelos: para escalas locais e regionais usou-se o algoritmo SEBAL, enquanto que para escalas continentais e globais utilizou-se o algoritmo MOD16. Em relação ao algoritmo SEBAL, a metodologia empregada apresentou bons resultados tanto nas estimativas pontuais dos fluxos de calor latente quanto em relação ao fechamento do balanço hídrico em grandes áreas. Em relação ao algoritmo MOD16, verificou-se que as estimativas de evapotranspiração apresentam melhores resultados a longo prazo e em grandes áreas. As análises aqui realizadas sugerem que os algoritmos SEBAL e MOD16 podem capturar razoavelmente bem as respostas da vegetação em relação à variabilidade espacial e temporal em larga escala. Considerando que esses algoritmos podem ser aplicados desde escalas regionais até escalas globais, os resultados estão em um intervalo aceitável de acurácia, indicando um potencial significativo no monitoramento espacial e temporal do processo de ET de forma contínua e sistemática a partir de informações obtidas por sensoriamento remoto. / Tropical vegetation is a major source of global land surface evapotranspiration (ET) and plays an important role in the global climate dynamics and in the processes of primary production of terrestrial ecosystems, since it is directly linked to the mass transfer and energy balance. The aim of this doctoral thesis was to evaluate the accuracy of ET estimates based on remote sensing models when compared to measurements obtained from flux towers and hydrological models. Two algorithms were selected: for local and regional scales SEBAL was used, while for continental and global scales, MOD16 was adopted. Regarding SEBAL algorithm, the applied methodology showed that significant results were achieved in both latent heat flux and water balance over large areas. Concerning MOD16 algorithm, the research suggested that evapotranspiration estimates showed better results in the long-term and in large areas. The analysis suggests that MOD16 and SEBAL algorithms can capture reasonably well the responses of vegetation in relation to spatial and temporal variability on a large scale. Taking into consideration that these algorithms can be applied from regional to global scales, the results are in an acceptable range of accuracy, indicating a significant potential for monitoring evapotranspiration using remote sensing data.

A vegetação tropical é uma das maiores fontes de evapotranspiração e desempenha um papel importante na dinâmica climática global e nos processos de produtividade primária de ecossistemas terrestres, uma vez que se encontra diretamente ligada aos processos de transferência de massa e energia. Objetivou-se nesta tese de doutorado avaliar a acurácia das estimativas de ET baseadas em modelos de sensoriamento remoto quando comparadas a medições pontuais obtidas a partir de torres de fluxo e a partir do fechamento do balanço hídrico a médio e longo prazo. Foram selecionados dois modelos: para escalas locais e regionais usou-se o algoritmo SEBAL, enquanto que para escalas continentais e globais utilizou-se o algoritmo MOD16. Em relação ao algoritmo SEBAL, a metodologia empregada apresentou bons resultados tanto nas estimativas pontuais dos fluxos de calor latente quanto em relação ao fechamento do balanço hídrico em grandes áreas. Em relação ao algoritmo MOD16, verificou-se que as estimativas de evapotranspiração apresentam melhores resultados a longo prazo e em grandes áreas. As análises aqui realizadas sugerem que os algoritmos SEBAL e MOD16 podem capturar razoavelmente bem as respostas da vegetação em relação à variabilidade espacial e temporal em larga escala. Considerando que esses algoritmos podem ser aplicados desde escalas regionais até escalas globais, os resultados estão em um intervalo aceitável de acurácia, indicando um potencial significativo no monitoramento espacial e temporal do processo de ET de forma contínua e sistemática a partir de informações obtidas por sensoriamento remoto. / Tropical vegetation is a major source of global land surface evapotranspiration (ET) and plays an important role in the global climate dynamics and in the processes of primary production of terrestrial ecosystems, since it is directly linked to the mass transfer and energy balance. The aim of this doctoral thesis was to evaluate the accuracy of ET estimates based on remote sensing models when compared to measurements obtained from flux towers and hydrological models. Two algorithms were selected: for local and regional scales SEBAL was used, while for continental and global scales, MOD16 was adopted. Regarding SEBAL algorithm, the applied methodology showed that significant results were achieved in both latent heat flux and water balance over large areas. Concerning MOD16 algorithm, the research suggested that evapotranspiration estimates showed better results in the long-term and in large areas. The analysis suggests that MOD16 and SEBAL algorithms can capture reasonably well the responses of vegetation in relation to spatial and temporal variability on a large scale. Taking into consideration that these algorithms can be applied from regional to global scales, the results are in an acceptable range of accuracy, indicating a significant potential for monitoring evapotranspiration using remote sensing data.

A vegetação tropical é uma das maiores fontes de evapotranspiração e desempenha um papel importante na dinâmica climática global e nos processos de produtividade primária de ecossistemas terrestres, uma vez que se encontra diretamente ligada aos processos de transferência de massa e energia. Objetivou-se nesta tese de doutorado avaliar a acurácia das estimativas de ET baseadas em modelos de sensoriamento remoto quando comparadas a medições pontuais obtidas a partir de torres de fluxo e a partir do fechamento do balanço hídrico a médio e longo prazo. Foram selecionados dois modelos: para escalas locais e regionais usou-se o algoritmo SEBAL, enquanto que para escalas continentais e globais utilizou-se o algoritmo MOD16. Em relação ao algoritmo SEBAL, a metodologia empregada apresentou bons resultados tanto nas estimativas pontuais dos fluxos de calor latente quanto em relação ao fechamento do balanço hídrico em grandes áreas. Em relação ao algoritmo MOD16, verificou-se que as estimativas de evapotranspiração apresentam melhores resultados a longo prazo e em grandes áreas. As análises aqui realizadas sugerem que os algoritmos SEBAL e MOD16 podem capturar razoavelmente bem as respostas da vegetação em relação à variabilidade espacial e temporal em larga escala. Considerando que esses algoritmos podem ser aplicados desde escalas regionais até escalas globais, os resultados estão em um intervalo aceitável de acurácia, indicando um potencial significativo no monitoramento espacial e temporal do processo de ET de forma contínua e sistemática a partir de informações obtidas por sensoriamento remoto. / Tropical vegetation is a major source of global land surface evapotranspiration (ET) and plays an important role in the global climate dynamics and in the processes of primary production of terrestrial ecosystems, since it is directly linked to the mass transfer and energy balance. The aim of this doctoral thesis was to evaluate the accuracy of ET estimates based on remote sensing models when compared to measurements obtained from flux towers and hydrological models. Two algorithms were selected: for local and regional scales SEBAL was used, while for continental and global scales, MOD16 was adopted. Regarding SEBAL algorithm, the applied methodology showed that significant results were achieved in both latent heat flux and water balance over large areas. Concerning MOD16 algorithm, the research suggested that evapotranspiration estimates showed better results in the long-term and in large areas. The analysis suggests that MOD16 and SEBAL algorithms can capture reasonably well the responses of vegetation in relation to spatial and temporal variability on a large scale. Taking into consideration that these algorithms can be applied from regional to global scales, the results are in an acceptable range of accuracy, indicating a significant potential for monitoring evapotranspiration using remote sensing data.

Submitted by Mario BC (mario@bc.ufrpe.br) on 2017-03-23T13:07:11Z No. of bitstreams: 1 Apolo Alves Ribeiro.pdf: 1727548 bytes, checksum: 8e7f8a7459cd445c7152921b7145c618 (MD5) / Made available in DSpace on 2017-03-23T13:07:11Z (GMT). No. of bitstreams: 1 Apolo Alves Ribeiro.pdf: 1727548 bytes, checksum: 8e7f8a7459cd445c7152921b7145c618 (MD5) Previous issue date: 2014-12-09 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Many important processes occurring in ecosystems, such as photosynthesis and productivity of vegetation, are associated with the exchange of CO2, water and energy. Accurate measurement of these fluxes are therefore fundamental to a broad understanding of the carbon cycle in terrestrial ecosystems. However, no such study was conducted under the conditions of the Agreste of Pernambuco, with the bean crop. Given the above, this study aimed to quantify the water, energy and CO2 fluxes in soil cultivated with bean under rainfed conditions. The study was conducted in a bean producing area of the city of São João, where were installed sensors to measure these fluxes, using the energy balance method - eddy covariance (energy and CO2 fluxes) and soil water balance method (water fluxes) in the period from 31/05/2013 to 08/20/2013. In addition to these measurements were also measured height, leaf area index (LAI) and the bean yield. Regarding the components of the water balance was found that the flow of water at a depth of 35 cm (deep drainage and/or capillarity rise) had very low values. It was also observed that the periods of high rainfall resulted in higher water storage in soil and increased evapotranspiration (ET). The ET obtained by water balance method had a total and average values of 146.0 mm and 1.78 mm d-1, respectively. The bean presented its highest water consumption during the reproductive period (29/06/2013 to 29/07/2013), with an average value of 2.55 mm d-1. Regarding the energy fluxes, it was found that the latent heat flux (LE) consumed on average 78.46% of the radiation (Rn). The ET, measured by the eddy covariance method, was total value of 179.3 mm, with a mean value of 2.2 mm d-1. Bean yield was 2,050 kg ha-1, with water use efficiency of 1.16 kg m-3. Regarding the CO2 fluxes, it was observed that the same varied from -11.21 to -0.75 mol m-2 s-1, indicating the occurrence of carbon sequestration by the crop. On average, bean sequestered 54 kg C ha-1 per day, the equivalent to 3.3 t C ha-1 during the trial period. / Muitos processos importantes que ocorrem nos ecossistemas, tais como, a fotossíntese e a produtividade da vegetação, estão associados com as trocas de CO2, água e energia. Medições precisas desses fluxos são, portanto, fundamentais para uma ampla compreensão do ciclo do carbono em ecossistemas terrestres. No entanto, nenhum estudo desse tipo foi realizado nas condições do agreste meridional de Pernambuco, com a cultura do feijão. Diante do exposto, o presente trabalho objetivou quantificar os fluxos de água, de energia e de CO2 em solo cultivado com feijão sob condições de sequeiro. O trabalho foi realizado em uma área produtora de feijão do município de São João, onde se instalou sensores para medir esses fluxos, usando as metodologias do balanço de energia - correlação dos turbilhões (fluxos de energia e de CO2) e do balanço hídrico no solo (fluxos de água) no período de 31/05/2013 a 20/08/2013. Também foram determinadas a altura, o índice de área foliar (IAF) e a produtividade do feijão. Em relação aos componentes do balanço hídrico verificou-se que o fluxo de água (drenagem profunda e/ou ascensão capilar) na profundidade de 35 cm teve valores muito baixos, como também que os períodos de elevada pluviosidade resultaram em maior armazenamento de água no solo e maior evapotranspiração (ET). A ET do feijão pelo método do balanço hídrico teve valor total e médio de 146,0 mm e 1,78 mm d-1, respectivamente. A cultura apresentou seu maior consumo de água no período reprodutivo (29/06/2013 a 29/07/2013), com valor médio de 2,55 mm d-1. Quanto aos fluxos de energia, verificou-se que o fluxo de calor latente (LE) consumiu em média 78,46% do saldo de radiação (Rn). A ET medida pela metodologia da correlação dos turbilhões obteve valor total durante o período experimental de 179,3 mm, com média de 2,2 mm d-1. A produtividade do feijão foi de 2.050 kg ha-1, com eficiência do uso de água de 1,16 kg m-3. Em relação aos fluxos de CO2, observou-se que os mesmos variaram de -0,75 a -11,21 mol m-2 s-1, indicando a ocorrência de sequestro de carbono pelo feijão. Em média, o feijão sequestrou 54 kg de C ha-1 por dia, o equivalente a 3,3 t de C ha-1 durante o período experimental.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The following study quantifies the seasonal and annual distribution of energy balance components (sensible heat fluxes, latent, soil, and net radiation) in this flooded irrigated rice ecosystem in Southern Brazil for three different periods (Fallow 1: 22 July 2003 to 24 November 2003; Rice: 25 November 2003 to 04 April 2004 and Fallow 2: 05 April 2004 to 21 July 2004). In addition, it has been applied the Noah Land Surface Model with the objective of estimating the surface energy fluxes. An important challenge is to implement a new version of Noah Land Surface Model applied to flooded agricultural land called Noah-Paddy. The stabilization of the models has been performed using the atmospheric forcing data obtained from South American Land Data Assimilation System (SALDAS) for the period 22 July 2000 to 21 July 2003. The models were simulated using the observed atmospheric forcing from a micrometeorological tower installed on a flooded irrigated rice paddies located in the city of Paraíso do Sul - RS. The initial conditions were obtained from the last time step of the spin-up experiment performed with atmospheric forcing data of SALDAS. The models results were compared with experimental data for surface energy fluxes. From the simulated results generated by the Noah Land Surface Model, it seems that when the rice crop is flooded, the model does not satisfactorily represents the experimental data. However, using the Noah-Paddy model the components of surface energy balance are more realistic for the system surface-water-atmosphere. The most important contribution performed in this research was to describe the diffent physical processes originated by the presence of a body of water between the soil surface and the atmosphere. This physical system occorr always in flooded agricultural crops in wich the rice paddies field are predominant. / No presente trabalho, quantifica-se a distribuição sazonal e anual das componentes do balanço de energia (fluxos de calor sensível, latente, do solo e saldo de radiação) em um ecossistema de arroz irrigado por inundação localizado no Sul do Brasil para três períodos distintos ao longo do ano (Pousio 1: 22Jul2003 a 24Nov2003; Arroz: 25Nov2003 a 04Abr2004 e Pousio 2: 05Abr2004 a 21Jul2004). Além disso, é utilizado o Modelo de Superfície Noah (Noah LSM) com o objetivo de estimar os fluxos de energia superficiais. Um dos desafios mais importantes é a implementação de uma nova versão do Noah LSM aplicado para áreas agrícolas alagáveis chamado Noah-Paddy. A estabilização dos modelos foi realizada utilizando dados de forçantes atmosféricas do South American Land Data Assimilation System (SALDAS) para o período de 22Jul2000 a 21Jul2003. Os modelos foram executados usando dados de forçantes atmosféricas observados obtidos a partir da torre micrometeorológica instalada sobre uma cultura de arroz irrigado por inundação localizada em Paraíso do Sul - RS. As condições iniciais foram obtidas a partir do último passo de tempo do experimento spin-up realizado com os dados de forçantes atmosféricas do SALDAS. O desempenho dos modelos estudados foi comparado com dados experimentais de fluxos de energia superficiais. A partir dos resultados obtidos pela simulação do Noah LSM verifica-se que, quando a cultura do arroz está irrigada, o modelo não representa satisfatoriamente os dados experimentais. Porém, utilizando o Noah-Paddy as trocas de energia superficiais são representadas de forma mais realísticas para o sistema superfície-água-atmosfera. A contribuição mais importante realizada neste trabalho foi a descrição dos diferentes processos físicos originados pela presença de uma massa de água entre a superfície do solo e a atmosfera. Esse sistema físico ocorre sempre em culturas agrícolas alagadas nas quais as plantações de arroz são predominantes.

<p><h1>This study discusses energy and water balance in an 80-year-old deciduous Carolinian forest in the Great Lakes region in southern Ontario, Canada. The eddy covariance technique and associated meteorological and soil variables were used to make a year-round measurements of energy and water vapour fluxes from January-December,2012. This site is part of the Turkey Point Flux Station and global Fluxnet. The linear relationship between daily turbulent (sensible heat (H), latent heat (LE)) and radiative fluxes (net radiation (Rn),soil heat (G) and canopy heat storage ( S)) has a the slope of 0.75 (intercept of -15.8 Wm^-2, and a correlation coefficient, r² of 0.93) indicating a 25% deficiency in energy balance closure. The mean value of canopy albedo was 0.16 during the growing season. Maximum daily evapotranspiration (E) rate was 3.8 mm day^-1 in June, when growing is at its peak in the region. Total annual E was 400 mm, which accounted for 42% of the total annual precipitation of 950 mm. The water storage in upper soil column (1.0 m depth) was approximately 100 mm, indicating that about 450 mm of water was lost from the forest as runoff. Apart from radiation, vapour pressure deficit (D) was the dominant control on E. Maximum value of bulk surface conductance (Gs) was about 18.5 mm s^-1. Gs linearly decreased in response to increase in D. The minimum Gs values were recorded when D was maximum, i.e. 3 to 3.5 kPa. Gs also showed high sensitivity to the volumetric soil water content (ϴ), during dry periods, for example the drought event in 2012. In the growing season, the typical value of Priestley-Taylor α ranged between 0.8 to 1.2 with a maximum of 1.8, indicating a wet deciduous forest. However, the LE/Rn relationship showed a linear increase with increasing D with a low (0.26) slope, indicating a conservative response of forest E to atmospheric demand. This study provides insight into energy partitioning, the water balance and their controls in this Carolinian deciduous forest. A better understanding of evapotranspiration processes and their controls in these forests would help to better quantify water availability at local and regional scales and to evaluate the impacts of future climate change on water resources in the region.</h1></p> / Master of Science (MSc)