An inter- and trans-disciplinary framework based on a European-South American research cooperation is proposed to underpin climate services inSouth America. Climate variability patterns linking the South American Monsoon region, including Amazonia, with southeastern South America,influence climate extremes and impact several societal sectors. More than 200 million people live in the region that is one of the world largest agricultural producing region and where the second world largest hydroelectric power plant is situated. Besides recent progress, further efforts are needed to better understand and predict regional climate variability. Project objectives are: 1) to better understand the combined role of remote andlocal drivers on South America climate variability from sub-seasonal to decadal timescales, and its impact on the occurrence and intensity of extremeevents. Special focus will be placed on an improved understanding of the effects of land use changes from the Amazon to the subtropics and theirimpact on extreme precipitation events; 2) to assess the predictability levels associated with regional climate pattern from sub-seasonal to decadal time scales; 3) to develop innovative regional prediction tools not only of climate variability but also of climate impact on both agriculture and hydrology in SSA on subseasonal and seasonal time scales; 4) to analyze climate knowledge co-production in order to revise how climate data are used by various stakeholders in their socio-cultural contexts; and 5) to analyze communication conditions of interdisciplinary and trans-disciplinary process of knowledge co-production that determines the usefulness of climate information in the process.Innovative technologies will be codeveloped to produce products and tools by the project for the SSA-RCC, agriculture and hydropower sectors. The project will be implemented in the context of the southern South AmericaRegional Climate Centre, and will include actors from the national meteorological services, agriculture and energy stakeholders and organizations.

Monsoon systems influence the water supply and livelihoods of over half of the world. Observations are too short to provide estimates of monsoon variability on the multi-year timescale relevant to the future or to identify the causes of change on this timescale. The credibility of future projections of monsoon behavior is limited by the large spread in the simulated magnitude of precipitation changes. Past climates provide an opportunity to overcome these problems. This project will use annually-resolved palaeoenvironmental records of climate variability over the past 6000 years from corals, molluscs, speleothems and tree rings, together with global climate-model simulations and high-resolution simulations of the Indian, African, East Asia and South American monsoons, to provide a better understanding of monsoon dynamics and interannual to multidecadal variability (IM). We will use the millennium before the pre-industrial era (850-1850 CE) as the reference climate and compare this with simulations of the mid- Holocene (6000 years ago) and transient simulations from 6000 year ago to ca 850 CE. We will provide a quantitative and comprehensive assessment of what aspects of monsoon variability are adequately represented by current models, using environmental modelling to simulate the observations. By linking modelling of past climates and future projections, we will assess the credibility of these projections and the likelihood of extreme events at decadal time scales. The project is organized around four themes: (1) the impact of external forcing and extratropical climates on intertropical convergence and the hydrological cycle in the tropics; (2) characterization of IM variability to determine the extent to which the stochastic component is modulated by external forcing or changes in mean climate; (3) the influence of local (vegetation, dust) and remote factors on the duration, intensity and pattern of the Indian, African and South American monsoons; and (4) the identification of paleo-constraints that can be used to assess the reliability of future monsoon evolution.