East Asian DecCen: Exploring Decadal to Century Scale Variability and Changes in the East Asian Climate during the last Millennium

The climate in East Asia is very complex, with profound variations on seasonal, interannual and longer time scales. On seasonal time scales, the East Asian Summer Monsoon (EASM) is dominating, leading to heavy rainfall in June, July and August along th ousands of kilometres long rain belts affecting China, Japan and Korea, encompassing one third of the world´s population. EASM contributes as much as 40-50% (60-70%) of the annual precipitation in the Yangtze River region (North China), so any long-term c hanges to EASM will have large implications for the region. On interannual time scales, variations in the El Nino-Southern Oscillation (ENSO) pattern are important. It is also known that remote regions, like the Atlantic and the Arctic, may influence the climate of East Asia through so-called teleconnection patterns. Long-term changes to seasonal and inter-annual variations, as well as variations on decadal to centennial time scales - underscore the importance of detecting and understanding decadal to cen tennial scale variations in the East Asian climate, and to attributing these variations to natural and human-induced forcings. In DecCen, a novel approach will be taken, linking Chinese and European climate students and scientists by combining new climate records covering the last millennium (through coring and analysis of glaciers in Tibet), historical and instrumental observations, numerical modelling and advanced statistical analysis. It is the consortium´s ambition to significantly contribute to the b asic understanding of decadal to centennial variations in the East Asian climate during the last millennium, and by that adding to the knowledge basis needed for a thorough assessment of possible changes in the climate during the 21st century in the regio n.