Evolución de la NAO durante los últimos 15000 años en la Península Ibérica y en Azores, a partir del estudio de registros lacustres y datos climáticos instrumentales

The North Atlantic Oscillation (NAO) and the El Niño – Southern Oscillation (ENSO) are two of the main climate modes that rule the globe natural climate variability on interannual and longer time scales. At multiannual scale, NAO oscillations accounts for more of the 50 % of the winter rainfall variance in northwestern Iberian meteorological stations. This climate mode also rules other climatic and environmental variables that have a direct impact on the terrestrial ecosystems like the plant growing season, the plant flowering period length, the tree ring growth and the location and development of many invertebrate, amphibian and bird species. NAO also has a strong and direct influence on lacustrine ecosystems through many ways, such as on lake water temperature, hydrological balance, and nutrient input and hence over the phytoplankton and zooplankton and therefore the whole food web. Despite the importance of this climate phenomenon for Europe, only some historical reconstructions based on documentary evidences and tree rings covering the last 1,500 years and few long-term (millennial scale) reconstructions using terrestrial sedimentary records of the NAO fluctuations have been carried out. Surprisingly, few multiproxy reconstructions of the NAO evolution have been conducted in the Azores islands, albeit being located in one end of the dipole. These NAO millennial-scale studies using terrestrial sedimentary archives are almost absent for the Iberian Peninsula though first attempts are currently in progress.

The main objective of this research project is to achieve a high-resolution spatial and temporalreconstruction of the North Atlantic Oscillation climatic phenomenon at multiannual-decadal resolution for the last 1,000 years and at millennial time-scale for the last 15,000 years in the southwestern Europe and Azores islands from the multiproxy characterization of lacustrine sediments.

This objective includes the following milestones:

• Geomorphological characterization of the lake catchments from Cimera and Peñalara Lakes(Central Mountains, Spain) and from a lake in São Miguel island (Azores Islands, Portugal).
• Multiproxy high-resolution characterization of the sedimentary cores taken from the selected lake systems.
• Paleolimnological and paleoclimate reconstruction at two temporal scale windows: last 1,000 years, and Lateglacial and Holocene periods.
• Identification and isolation of the NAO climate signal from the other signals in each temporal scale window and studied locality.
• Development of long and high-quality instrumental climate (temperature and precipitation) records (both regional and single sites timeseries) and compilation of the NAO Indices (NAOi).
• Assessments of intraannual, interannual, decadal and interdecadal relationships between NAO and the surface climate of Central Iberia and Azores.
• Exploratory analysis between multiproxies from the sedimentary lacustrine cores and Central Iberia and Azores instrumental climate timeseries.
• Characterization of the NAO climate signal transmission from the atmosphere to the sediments for the last 1,000 years.
• Comparison of the reconstructed NAO climate signals in order to characterize the spatial-temporal evolution of this climate phenomenon.

Researchers

• Santiago Giralt Romeu,ICTJA-CSIC, Barcelona, Spain, Project Leader
• Roberto Bao, Universidad A Coruña, Spain
• Manola Brunet, Universitat Rovira i Virgili, Spain
• Teresa Buchaca, Centre Avançat d’estudis de Blanes (CEAB-CSIC), Spain
• Miriam Gomez-Paccard, ICTJA-CSIC, Barcelona, Spain
• Vitor Gonzalves Universidade das Açores, Portugal
• Ignacio Granados, Parque Natural de Peñalara, Spain
• Armand Hernandez, Universidade de Lisboa, Portugal
• Olga Margalef, ICTJA-CSIC, Barcelona, Spain, Spain
• Sergi Pla, Centre Avançat d’estudis de Blanes (CEAB-CSIC)
• Juan Jose Pueyo, Universitat de Barcelona, Spain
• Pedro Raposeiro, Universidade das Açores, Spain
• Ma Jesus Rubio, ICTJA-CSIC, Barcelona, Spain
• Valenti Rull, Institut Botanic de Barcelona (IBB-CSIC), Spain
• Alberto Saez, Universitat de Barcelona, Spain
• Angel Salazar, Insituto Geologico y Minero de España (IGME), Spain
• Guiomar Sanchez, ICTJA-CSIC, Barcelona, Spain
• Javier Sigro, Universitat Rovira i Vigili, Spain
• Manuel Toro, Centro de Estudios y Experimentacion de Obras Publicas (CEDEX), Spain
• Ricardo Trigo, Universidade de Lisboa, Portugal
• Blas Valero, Instituto Pirenaico de Ecologia (IPE-CSIC), Spain
• David Vazquez, Universidad A Coruña, Spain

PROJECT INFO

Project Leader: Santiago Giralt Romeu

• Years: 2007-2012

• Funding

  Project Financed by PNIDI CGL – CGL2010-15767