Made available in DSpace on 2017-05-12T14:48:28Z (GMT). No. of bitstreams: 1 Patricia de Oliveira Drechmer.pdf: 703873 bytes, checksum: c5f64d1a8f42cf596ce9e2edd113b6b8 (MD5) Previous issue date: 2005-08-01 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / This paper shows the comportment of solar radiation global, direct and diffuse radiation at Cascavel, classifies the sky s cover in function of the cloudiness index and studies the applicability of the numeric correction of RICIERI (1998) on diffuse radiation measured with a shadow ring. The research was done at meteorological experimental station of UNIOESTE, Cascavel. The solar radiation components were monitored from January 03, 2001 to February 14, 2003. The global radiation was monitored by a pyranometer KIPP & ZONEN-CM3 and the direct radiation were monitored by a pyrheliometer EPPLEY-NIP coupled to a solar tracer. The diffuse radiation was monitored by the difference between global radiation and direct radiation projected over the horizontal surface and by a pyranometer covered by a shadow ring. The monthly average levels of the global, direct and diffuse irradiations were 51,8%, 31,7% and 20,17% of the irradiation over the atmosphere s top. The diffuse irradiation measured by the difference method and by the shadow ring method corrected by DRUMMOND s factor and compared through the relative daily deviation. It was observed that, in 94% of the days, the diffuse radiation by DRUMMOND s factor was lower than the difference method. The deviations were higher for cloudless days (19,82%), than for partially cloudy days (9,55%) and cloudy days (2,68%). The RICIERI s correction (1998), that proposes the correlation of diffuse irradiation without correction with the diffuse irradiation by the difference method, was used and the linear function Rd=0,16545+1,21715R d was found to correct the diffuse by the shadow ring method. This correction increases the precision of the diffuse fraction obtained by shadow ring, decreasing the average relative deviation from 11,79%, when the DRUMMOND s correlation was applied, to 7,37%. In order to increase the model s precision, it was proposed the partial numeric equation fitted in function of the sky s cover. It was verified decrease mean values of relative deviation, when compared with the DRUMMOND s correction: 4,8% in cloudless sky, 4,66% in partially cloudy sky and, 4,6% in cloudy sky. The average relative deviation was 4,68%. The diffuse solar radiation measured on Cascavel-PR and corrected by RICIERI s numeric function, determined to region of Botucatu - SP, shows relative deviation to cloudy sky, partially cloudy sky and cloudless sky, respectively, 4,6%, 4,8% and 5,29%, suggesting that the functions developed to Botucatu - SP tend to be independent from the locality. / O presente estudo caracteriza o comportamento da radiação solar global, direta e difusa na cidade de Cascavel, classifica o tipo de cobertura do céu em função do índice de claridade e avalia a aplicabilidade da função numérica de RICIERI (1998) na correção da radiação solar difusa obtida com do anel de sombreamento. As componentes da radiação solar foram monitoradas durante o período de 3 de janeiro de 2001 a 14 de fevereiro de 2003 na Estação Experimental Agrometeorológica da UNIOESTE, Campus de Cascavel. Na medição da radiação global e difusa foi utilizado um piranômetro KIPP & ZONEN-CM3 e para medir a componente direta foi utilizado um pireliômetro EPPLEY-NIP acoplado a um rastreador solar. A radiação difusa foi monitorada de duas formas: através da diferença entre a radiação global e a radiação direta projetada no plano horizontal e através de um piranômetro sombreado por um anel. Os níveis médios mensais das irradiações global, direta na incidência e difusa, foram respectivamente, 51,8%, 31,7% e 20,17% da radiação incidente no topo da atmosfera. Os níveis da irradiação difusa medidos pelo método da diferença e anel de sombreamento corrigido pelo fator de DRUMMOND (1956) foram monitorados e comparados utilizando o desvio relativo diário. Foi verificado que, em 94% dos dias, a radiação difusa corrigida por DRUMMOND foi inferior à obtida pelo método padrão. Os desvios são maiores para dias de céu limpo (19,82%), que para céu parcialmente nublado (9,55%) ou nublado (2,68%). Foi empregado o método de correção sugerido por RICIERI (1998), que propõe a correlação entre a irradiação difusa sem correção e a irradiação difusa de referência, e a função numérica linear Rd=0,16545+1,21715R d foi proposta. Essa correlação melhora em cerca de 37% a correção da fração difusa, diminuindo o desvio relativo médio de 11,79%, calculado para o método de DRUMMOND, para 7,37%. As funções numéricas parciais, propostas em função do tipo de cobertura do céu, diminuem significativamente o valor do desvio relativo médio, quando comparada ao fator de correção de DRUMMOND: 4,80% para céu limpo, 4,66% para céu parcialmente nublado e 4,60% para céu nublado, sendo o desvio relativo médio igual a 4,68%. A radiação solar difusa medida em Cascavel - PR e corrigida com as funções numéricas de RICIERI, determinadas para a região do município de Botucatu - SP, mostraram desvios relativos médios para dias de céu nublado, parcialmente nublado e limpo, respectivamente, 4,60%, 4,80% e 5,29%, sugerindo que estas tendem a independer da localidade.

Les caractéristiques des rayonnements solaires dépendent fortement de certains événements météorologiques non observés comme fréquence, taille et type des nuages et leurs propriétés optiques (aérosols atmosphériques, al- bédo du sol, vapeur d’eau, poussière et turbidité atmosphérique) tandis qu’une séquence du rayonnement solaire peut être observée et mesurée à une station donnée. Ceci nous a suggéré de modéliser les processus de rayonnement solaire (ou d’indice de clarté) en utilisant un modèle Markovien caché (HMM), paire corrélée de processus stochastiques. Notre modèle principal est un HMM à temps continu (Xt, yt)t_0 est tel que (yt), le processus observé de rayonnement, soit une solution de l’équation différentielle stochastique (EDS) : dyt = [g(Xt)It − yt]dt + _(Xt)ytdWt, où It est le rayonnement extraterrestre à l’instant t, (Wt) est un mouvement Brownien standard et g(Xt), _(Xt) sont des fonctions de la chaîne de Markov non observée (Xt) modélisant la dynamique des régimes environnementaux. Pour ajuster nos modèles aux données réelles observées, les procédures d’estimation utilisent l’algorithme EM et la méthode du changement de mesures par le théorème de Girsanov. Des équations de filtrage sont établies et les équations à temps continu sont approchées par des versions robustes. Les modèles ajustés sont appliqués à des fins de comparaison et classification de distributions et de prédiction. / Characteristics of solar radiation highly depend on some unobserved meteorological events such as frequency, height and type of the clouds and their optical properties (atmospheric aerosols, ground albedo, water vapor, dust and atmospheric turbidity) while a sequence of solar radiation can be observed and measured at a given station. This has suggested us to model solar radiation (or clearness index) processes using a hidden Markov model (HMM), a pair of correlated stochastic processes. Our main model is a continuous-time HMM (Xt, yt)t_0 is such that the solar radiation process (yt)t_0 is a solution of the stochastic differential equation (SDE) : dyt = [g(Xt)It − yt]dt + _(Xt)ytdWt, where It is the extraterrestrial radiation received at time t, (Wt) is a standard Brownian motion and g(Xt), _(Xt) are functions of the unobserved Markov chain (Xt) modelling environmental regimes. To fit our models to observed real data, the estimation procedures combine the Expectation Maximization (EM) algorithm and the measure change method due to Girsanov theorem. Filtering equations are derived and continuous-time equations are approximated by robust versions. The models are applied to pdf comparison and classification and prediction purposes.

Modelling solar radiation data at a high spatiotemporal resolution for an urban environment can inform many different applications related to climate action, such as urban agriculture, forest, building, and renewable energy studies. However, the complexity of urban form, vastness of city-wide coverage, and general dearth of climatological information pose unique challenges doing so. To address some climate action goals related to reducing building emissions in the City of Victoria, British Columbia, Canada, applied geomatics and climatology were used to model solar radiation data suitable for informing renewable energy feasibility studies, including photovoltaic system sizing, costing, carbon offsets, and financial payback. The research presents a comprehensive review of solar radiation attenuates, as well as methods of accounting for them, specifically in urban environments. A novel methodology is derived from the review and integrates existing models, data, and tools – those typically available to a local government. Using Light Detection and Ranging (LiDAR), a solar climatology, Esri’s ArcGIS Solar Analyst tool, and Python scripting, daily insolation (kWh/m2) maps are produced for the city of Victoria. Particular attention is paid to the derivation of daily diffuse fraction from atmospheric clearness indices, as well as LiDAR classification and generation of a Digital Surface Model (DSM). Novel and significant improvements in computation time are realized through parallel processing. Model results exhibit strong correlation with empirical data and support the use of Solar Analyst for urban solar assessments when great care is taken to accurately and consistently represent model inputs and outputs integrated in a methodological approach. / Graduate