PACMEDY: PAlaeo-Constraints on Monsoon Evolution and Dynamics

Funded Project Information
Climate Predictability and Inter-Regional Linkages
Lead PI: 
Pascale Braconnot, Centre National de la Recherche Scientifique, France
Sandy P. Harrison, University of Reading, UK
Alexander Tudhope, University of Edinburgh, UK
Christopher Brierley, University College London, UK
Krishnan Raghavan, Indian Institute of Tropical Meteorology, India
Johann H. Jungclaus, Max Planck Institute for Meteorology, Germany
Eduardo Zorita, Helmoltz-Zentrum Geesthacht, Germany
Gerrit Lohmann, Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Germany
Francesco Salvatore Rocco Pausata, Stockholm University, Sweden
Thierry Corrège, EPOC, France
Bruno Turcq, Laboratoire d'Océanographie et du Climat: Expérimentations et Analyses Numériques-IPSL/Pierre et Marie Curie University/IRD/CNRS/MNHN, France
Matthieu Carré, Institut des Sciences de l'Evolution de Montpellier, France
Luc Beaufort, CEREGE, France
Mary Elliot, Laboratoire de Planetologie et Geodynamique de Nantes, France
Pedro Leite da Silva Dias, University of São Paulo, Brazil

Belmont Forum and JPI Climate sponsors: FAPESP, ANR, BMBF, MoES, FORMAS, NERC

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.