Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-01T19:16:26Z No. of bitstreams: 1 PatriciaVianaDeLima_DISSERT.pdf: 1302914 bytes, checksum: 9dcae03eb379346b11d0fa6dda2a1c37 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-06T19:53:19Z (GMT) No. of bitstreams: 1 PatriciaVianaDeLima_DISSERT.pdf: 1302914 bytes, checksum: 9dcae03eb379346b11d0fa6dda2a1c37 (MD5) / Made available in DSpace on 2016-04-06T19:53:19Z (GMT). No. of bitstreams: 1 PatriciaVianaDeLima_DISSERT.pdf: 1302914 bytes, checksum: 9dcae03eb379346b11d0fa6dda2a1c37 (MD5) Previous issue date: 2014-08-15 / A an?lise de s?ries temporais tem desempenhado um papel cada vez mais importante em estudos de tempo e clima. O sucesso desses estudos depende fundamentalmente do conhecimento da qualidade de dados clim?ticos, como temperatura do ar e precipita??o. Por essa raz?o, um dos principais desafios para os pesquisadores nessa ?rea ? obter s?ries homog?neas. Uma s?rie temporal de dados clim?ticos ? considerada homog?nea quando as varia??es nos dados se devem somente a fatores clim?ticos, sem interfer?ncia de agentes externos. Tais fatores n?o clim?ticos podem produzir efeitos indesej?veis nas s?ries temporais, como quebras de homogeneidade, tend?ncias e descontinuidades que na realidade n?o existem. Neste trabalho foram investigadas s?ries clim?ticas para o munic?pio de Natal ? RN, representando temperatura do ar e precipita??o, para o per?odo de 1961 a 2012. O objetivo foi realizar uma an?lise a fim de verificar a exist?ncia de pontos de quebra de homogeneidade e de tend?ncias nas s?ries estudadas. Para esse fim, foram usados alguns procedimentos estat?sticos b?sicos, como testes de normalidade e de independ?ncia. Os testes de tend?ncia foram feitos atrav?s da an?lise de regress?o linear e dos testes de Spearman e de Mann-Kendall. Para an?lise de homogeneidade, foram usados essencialmente os testes SNHT, Eeasterling-Peterson e Mann-Whitney-Pettit. As an?lises com respeito ? normalidade mostraram diverg?ncia em seus resultados. O teste de Von Neumann mostrou que para a s?rie de temperatura os dados n?o s?o independente e identicamente distribu?dos (iid), ao passo que para a s?rie de precipita??o os dados s?o iid De acordo com os testes realizados, ambas as s?ries apresentam tend?ncias. A s?rie de temperatura m?dia do ar apresenta tend?ncia crescente, enquanto a s?rie de precipita??o acumulada apresenta tend?ncia decrescente. Finalmente, os testes de homogeneidade revelaram que nenhuma das s?ries ? homog?nea, embora que os pontos de quebras dependam do teste aplicado. Em geral, os resultados mostram que as aplica??es das t?cnicas escolhidas permitem caracterizar bem as s?ries estudadas. Portanto, esses resultados poder?o servir de base para futuros trabalhos sobre a climatologia de Natal, assim como de outros lugares. / The time series analysis has played an increasingly important role in weather and climate studies. The success of these studies depends crucially on the knowledge of the quality of climate data such as, for instance, air temperature and rainfall data. For this reason, one of the main challenges for the researchers in this field is to obtain homogeneous series. A time series of climate data is considered homogeneous when the values of the observed data can change only due to climatic factors, i.e., without any interference from external non-climatic factors. Such non-climatic factors may produce undesirable effects in the time series, as unrealistic homogeneity breaks, trends and jumps. In the present work it was investigated climatic time series for the city of Natal, RN, namely air temperature and rainfall time series, for the period spanning from 1961 to 2012. The main purpose was to carry out an analysis in order to check the occurrence of homogeneity breaks or trends in the series under investigation. To this purpose, it was applied some basic statistical procedures, such as normality and independence tests. The occurrence of trends was investigated by linear regression analysis, as well as by the Spearman and Mann-Kendall tests. The homogeneity was investigated by the SNHT, as well as by the Easterling-Peterson and Mann-Whitney-Pettit tests. Analyzes with respect to normality showed divergence in their results. The von Neumann ratio test showed that in the case of the air temperature series the data are not independent and identically distributed (iid), whereas for the rainfall series the data are iid. According to the applied testings, both series display trends. The mean air temperature series displays an increasing trend, whereas the rainfall series shows an decreasing trend. Finally, the homogeneity tests revealed that all series under investigations present inhomogeneities, although they breaks depend on the applied test. In summary, the results showed that the chosen techniques may be applied in order to verify how well the studied time series are characterized. Therefore, these results should be used as a guide for further investigations about the statistical climatology of Natal or even of any other place.