Reconstruction and model simulations of past climate in Portugal using documentary and early instrumental sources (17th-19h century) (Klimhist)

Climate change is a main concern of population, scientists and governments. Predictions for the next decades and decisions to mitigate and/or to adapt to climate variability and change need to be based on the knowledge of the past. Although for some areas of the globe, and for the last two (or three) centuries, climate change can be deduced from instrumental series, there are several spatial and temporal gaps particularly when it comes to pre-instrumental era. European wide temperature and precipitation reconstructions [LUT2000] clearly point to the fact that more highly resolved information is needed for a better understanding of climate change in

SW Europe. As Portugal is situated between the Azores High and the Icelandic Low, and between the Atlantic and Mediterranean types of climates, climate reconstruction in Portugal will supply very valuable information to assess the role of the anthropogenic forcing on climatic variability.

The interdisciplinary team of climatologists, geographers, historians and physicists will work towards answering the questions: how was natural climate variability in the past? Are extremes more frequent nowadays? What were the climate trends in the last 350 years in Portugal? Some promising findings resulting from the EU ADVICE project have permitted to reconstruct temperature and precipitation variability during the LMM, to extend the precipitation series at Lisbon back to 1835 and to study some extreme weather events [ALC2000][TAB2004]. We have collaborated in climate reconstructions [CAM 2010a, 2010b] and in the study of great 18th century storms and their impacts [PFI 2010] within the frame of the MILLENNIUM project. Some team members participated in the EU MICE project, aiming at modelling the impacts of climate extremes in Europe and the assessment of future climate scenarios [SAN 2006, 2007]. Extreme value and trend analysis were also recently undertaken for Portugal [SAN 2009].Significant expertise was gained from these projects, particularly in analysing climatic variability.

Climatic variability from the beginning of regular meteorological observations (in the last decades of the 19th century in Portugal) is now acknowledged. However, climate change prior to 1900 is far from being well known in Portugal. This project will concentrate on documentary evidence and early instrumental data from 1645 (beginning of the Maunder Minimum) to 1900 (beginning of the DISASTER Project, (please see lit.review). It will adapt the methods first proposed by Pfister [BRA2005, 2010]. The team is aware of the existence of several new or partially exploited sources of this nature, which have not yet been used in climatic change studies.

THE EXACT TEMPORARY AND SPATIAL LIMITS OF THE RECONSTRUCTED SERIES WILL DEPEND ON CLIMATIC DATA AVAILABILITY AND QUALITY WITHIN THE RESEARCHED SOURCES. The strategy will be different in Northern and Southern Portugal, as the team possesses more data concerning the south of the country, where calibration and verification are more developed.

The objectives and expected results are as follows: 1. TO CONTRIBUTE TO THE CREATION OF A LONG-TERM HISTORY OF CLIMATE IN PORTUGAL by: producing databases of documentary evidence and of instrumental data since 1645, a period of natural climate variability that includes the Maunder Minimum (1645-1715) and the Dalton Minimum (1790-1820); systematically searching for the first simultaneous documentary and instrumental data (late 18th,/early 19th century); reconstructing time series (annual/seasonal scales) for Portugal; analyzing simulated multi-decadal trends over Portugal generated by climate models; comparing our results with those obtained from dendroclimatology and from geothermal studies regarding Portugal. 2. TO HELP COMPLETING THE SPATIAL COVERAGE OF PAST EUROPEAN CLIMATE, as the data gap over SW Europe is often mentioned in several studies: by disseminating data and model outputs to the scientific community (internet); by interacting with a group of renowned Spanish researchers in the field (Salva-Sinobas project http://salva-sinobas.uvigo.es/); through the interaction with our consultants, all of them with active research in the historical climatology of Europe. 3. TO VALIDATE RECONSTRUCTED SERIES using climate models and proxy data. 4. TO ASSESS THE ROLE OF NATURAL VS. ANTHROPOGENIC FORCING ON CLIMATIC VARIABILITY IN PORTUGAL in the past, which will then help understand the recent variability and will enable a validation of the future climatic scenarios projected by climate models. 5.TO STUDY EXTREME EVENTS OF THE PAST, THEIR IMPACTS AND THE VULNERABILITY OF SOCIETIES to weather during the last 350 years, in order to understand how they have changed in time [PFI2010a, 2010b] and compare them with current analogues [FRA 2008]. 6. TO DEVELOP AND DISSEMINATE HISTORICAL CLIMATOLOGY IN PORTUGAL, also encouraging MSc or PhD students to study this topic.