El clima en la región de Zafra durante el periodo 1750-1841

Resumen

This Thesis analyzes the climate in Zafra (Southwest Spain) during the period 1750-1840 using documents related to the administration of the Duchy of Feria. Specifically, the documentary sources belong to a subsection of the Zafra Municipal Archive denominated �Consultas y Decretos del Ducado de Feria�. The �Consultas� are weekly reports submitted to the Duke, who lived in Madrid, describing the most relevant events occurring in his lands. From to the �Consultas�, a monthly index of percentage of rainy weeks was constructed for the period 1750-1840. Two wet sub-periods (from 1782 to 1789 and from 1801 to 1807) and two dry sub-periods (from 1796 to 1798 and from the middle of 1816 to 1819) were detected. The �Consultas� also provide descriptive information about of temperature. Therefore, a monthly index of temperature was created for all the study period. Four cold sub-periods (1787-1790, 1805-1807, 1825-1827 and 1832-1837) and three warm sub-periods (1777-1779, 1795-1800 and 1823-1825) were identified. In order to evaluate the rainfall and temperature monthly index reliability, these series were compared with the existing instrumental series in the Southwest of the Iberian Peninsula (Mafra, Madeira, Lisbon, Seville, Cadiz and Gibraltar). Moreover, atmospheric circulation over the North Atlantic and his relationship with the extreme rainfall and temperature monthly index was studied. Finally, descriptions of other relevant meteorological events occurred in Zafra during the period 1750-1840 were studied.