IGBP-PAGES-PEP III

The Pole-Equator-Pole Afro-European Transect

Organised by MEDIAS-FRANCE and the Paleoclimate Team of URA-CNRS 723 (Orsay, France), with the support of IGBP-PAGES, IGBP-START, the European Science Foundation, the National Science Foundation (USA), the " Centre National de la Recherche Scientifique " (France), and the INQUA-PAGES Paleomonsoon project, this meeting brought together 78 scientists from 24 countries..

 The purpose of the meeting was to stimulate the development of multidisciplinary and interdisciplinary activities between paleoclimate scientists from North to South and West to East around the major PEP III scientific questions as addressed in the PANASH Project (PAGES Report, 1995).

 PEP III aims at expanding our understanding of the interhemispheric dynamics of past climate changes. Major paleoclimate questions concern: (i) the impact of the northern ice-sheet growth and decay on European climate and on the oceanic thermohaline circulation; (ii) the causes and mechanisms of hydrological changes over the Sahara-Sahel; (iii) the variability of the monsoon; (iv) the response of southern Africa to changes in the southern ice-sheet and sea-ice extent, and in the ocean general circulation. Two time scales are considered: the past 250,000 years (Time Stream II), and the past 2,000 years (Stream I).

 The workshop has enabled to: (i) summarise the state of the art of our knowledge concerning the main PEP III scientific questions; (ii) strengthen the development of thematic working groups and establish a strategy to make working groups efficient in data acquisition; (iii) stimulate the further development of regional PEP III coordination committees; (v) establish backgrounds for protocols for interdisciplinary data management and integration.

Some thirty oral communications were presented dealing with: (i) the PAGES and PEP III general objectives, and linkages between PEP III and other current international programmes (PMIP, PMAP, IMAGES, etc.); (ii) the main research topics developed within PEP III either at the regional scale (the northern ice sheet and past European climates, mountain glaciers, loess records, lake records from high and low latitudes, the Mediterranean, etc.), or concerning specific " systems " or proxies (e.g., pollen, tree-rings, speleothems, groundwater, isotopes, etc.); (iii) organisation of PEP III activities at the regional and/or national scale. About 30 posters illustrated scientific results from specific sites or methods.

 Several working groups were held which led to a series of recommendations to be published in the Workshop report. Some major points of particular interest for the MEDIAS regions are outlined below :

 - PEP III Time Stream I. The aims and the scientific, geographic, and methodological priorities have been refined. Greater emphasis should be given to collaboration between paleoclimate scientists and archaeologists, especially for studies in the Nile Valley, East African highlands and coast, Madagascar highlands and coast, Southern Africa. The need for a PEP III Stream I data base has been enforced.

 - Subsurface waters as archives of paleoclimate. One of the key scientific issues that can be addressed by paleoclimate data from subsurface waters is the verification of climate models. Furthermore, in arid regions, water in the saturated and unsaturated zone may be the only climate indicators available. The working group recommends acquisition of new data especially in Africa and Middle East. It encourages the development of a data base on existing information in connection with the Section of Isotope Hydrology of the International Agency of Atomic Energy (Vienna).

 - Paleomonsoon. The group encourages studies of the catchment basin of major rivers and their marine delta (Nile, Senegal, Niger, Congo, Zambezi, Tigre, Euphrates). The history of the major African biomes (equatorial forest, tropical dry forest, savannas) needs detailed research, in order to understand the role of tropical regions in the carbon cycle and their influence on the chemical composition of the atmosphere and its aerosol content.

 All the working groups have recognised the fundamental need to develop a pluridisciplinary PEP III Data Base with free exchange of data between researchers from different disciplines. This data base should soon be initiated at MEDIAS-FRANCE (Toulouse).

 The reports of the Bierville meeting will be published in 1997 in a PAGES Report, which will include the reports of a meeting held in Siwa (Egypt) in January 1997 in the framework of the INQUA-PAGES " Paleomonsoon " project.