ABSTRACT:The year 1816 was characterized by unusual weather conditions, in particular, by a cold and wet summer season ('year without a summer') on both the European and North American continents. The eruption of Tambora, an active stratavolcano, on the Island of Sumbaya (Indonesia) in April 1815 has been identified as the main driving force for the strong 1816 temperature anomaly. This climate anomaly has been relatively well studied in central Europe, France, Scandinavia and the United Kingdom. The unusual unsettled weather and climate at mid-latitudes in 1816 and 1817 had major socioeconomic impacts, particularly in terms of a poor yield of agricultural production, malnutrition and consequentially an increased potential for diseases and epidemics. The Iberian Peninsula was also affected by the intense climate anomalies during those years. Documentary sources describe the impact that the cold and wet summer of 1816 had on agriculture, namely the bad quality of fruits, delayed ripening of vineyards and cereals.It is within this context that we stress the relevance of recently recovered meteorological observed data, from 1816 onwards, for stations located in Portugal (Lisbon) and also for a longer period for the Spanish stations of Madrid, Barcelona and San Fernando-Cadiz. We have compared observed (station-based) and large-scale reconstructed seasonal temperature anomalies computed for the winter and summer seasons after the eruption (1816-1818). There is qualitative agreement between the two independent data sets, though some stations partly indicate stronger departures from the long-term averages for single years compared to neighbouring grid points. In particular, all available stations reveal a cold summer of 1816, mainly in July and August. In comparison to the 1871-1900 reference period, those two months were 2-3°C cooler, close to what has been reported for central Europe. We also discuss the regional climate anomalies for those years (1816-1818) using independently reconstructed atmospheric circulation fields.

Abstract. Natural proxies, documentary evidence and instrumental data are the only sources used to reconstruct past climates. In this paper, we present the 18th century meteo-

This paper discusses the research carried out to check the climatic characteristics of the late Maunder Minimum (LMM) (AD 1675–1715) in the southwestern part of the Iberian Peninsula and as an aid towards pressure patterns reconstruction in the NE Atlantic and Europe. Documentary evidence reveals that interannual precipitation variability was similar to the present one, although some very severe dry periods occurred (particularly one in 1694). On the other hand, during the LMM there was a higher percentage of cold winter months, some of them with snowfall. A brief comparison is made with other areas from the Mediterranean. The relationships between weather similarities and differences for particular months is analysed in the light of the reconstructed synoptical patterns, and further research into historical climatic change of southern Europe is suggested.

Three violent eighteenth-century storms that ravaged the North Sea area (1703), western central Europe (1739) and Portugal (1739) are investigated from the point of view of their meteorological setting, their socio-economic impact, and whether and by what means they secured an enduring place in the cultural memory. The evidence draws on individual narrative sources such as chronicles and poems, and institutional sources such as ship's logbooks and state-organised 'windthrow' inventories of tree loss. Each of the three storms had socio-economic impacts that could be described as 'war-like' in the damage caused to buildings and the destruction of forests. The "Great Storm" of December 1703 jeopardized English naval supremacy in the War of the Spanish Succession by sinking a number of Royal Navy ships and taking the life of more than 8000 seamen. In January 1739 two similarly destructive storms swept over mainland Europe. The cultural memory of the three events here considered was however strikingly different. The C. Pfister (B)

Resumo -As observações meteorológicas instrumentais, em Portugal, têm iní-cio nos anos 70 do século XVIII. O clima de Portugal anterior àquela década tem vindo a ser reconstituído exclusivamente com base em fontes documentais descritivas, em que, de um modo geral, são os extremos climáticos que surgem registados. Dada a subjectividade que este tipo de informação encerra, a análise crítica do maior número de fontes possível é um procedimento essencial. Analisa-se aqui o temporal ocorrido em grande parte do território de Portugal continental, entre 3 e 6 de Dezembro de 1739. À violência do vento do quadrante Sul, que pelos efeitos relatados poderá ter atingido velocidades da ordem dos 120km/h, associaram-se chuvas contínuas e intensas, que originaram cheias nas bacias dos rios Tejo, Mondego e Douro. Os prejuízos foram muito avultados, havendo referências à perda de vidas humanas e à morte de muitos animais. Tal como na actualidade, também no passado estes episódios de ventos fortes e de chuvas intensas ocorreram em situação de fluxo do quadrante Sul. Palavras-chave:Climatologia histórica, fontes documentais descritivas, Portugal, século XVIII, fenómenos meteorológicos extremos.Abstract -THE WEATHER IN PORTUGAL BETWEEN 3 AND 6 DECEMBER 1739 (BASED ON DESCRIPTIVE DOCUMENTAL SOURCES). Instrument-based meteorological observations in mainland Portugal started to be gathered in the 1770s. Weather in Portugal before that time can therefore only be reconstructed based on descriptive documental sources in which generally only extreme weather events are recorded. Due to the subjectivity of this type of information, critical analysis of the sources, their diversity and data crossing prove essential in order to be able to assess their trust-worthiness. Here we have chosen to analyse a gale that swept across much of mainland Portugal between 3 and 6 December 1739. The violent winds coming from the South, which according to reports may have reached speeds of 120km/h, were accompanied by heavy, continuous rain that produced flooding in the basins of the rivers Tagus, Mondego and Douro. Large-scale damage would have occurred, backed up by references to the death of many animals and the loss of human lives. As nowadays, these storm events were originated from winds coming from the South . Finisterra, XLI, 82, 2006, pp. 73-86 1 Professor de Geografia, Escola Secundária Gabriel Pereira, Évora. E-mail: joaotaborda@hotmail.com Key words: Historical climatology, descriptive documental sources, Portugal, 18 th century, extreme meteorological phenomena.Résumé -TENTATIVE DE RECONSTITUTION DE LA TEMPÊTE DU 3 AU 6 DÉCEMBRE 1739 AU PORTUGAL. Les reconstitutions climatiques antérieures aux années 70 du XVIII ème siècle ne peuvent s'appuyer au Portugal que sur des sources documentaires descriptives, lesquelles enregistrent surtout les situations extrêmes. D'où l'importance de l'analyse critique et du croisement de sources si possible multiples. La tempête qui a sévi sur la plus grande partie du Portugal, du 3 au 6 décembre 1739, était associ...