CORDEX - South America: Present climate and future change

SILVINA A SOLMAN

Bruselas

Conferencia; International Conference on Regional Climate Change CORDEX 2013; 2013

World Climate Research Programme- IPCC- European Commission

In this presentation a thorough revision of the status the CORDEX Phase I and Phase II over the South American CORDEX domain is discussed. The availability of a set of coordinated Regional Climate simulations over the South American domain have led to an unprecedented achievement for quantifying uncertainties in both the present climate simulations and the ensemble projections of climate change over South America. ERA-Interim forced simulations performed with more than 11 RCMs allowed characterizing the major strength and shortcomings of our current capability in reproducing observed climate conditions, in terms of both mean climate conditions and its interannual variability. Overall, it was found that some systematic biases were identified, such as an overestimation of temperature and underestimation of precipitation over the La Plata basin (LPB) region. Individual model?s biases over tropical areas of South America were diverse, depending on the model. The Andean region was characterized by a strong underestimation of temperature and overestimation of precipitation mainly over the Andean slopes, a common shortcoming of every modeling effort for the region. The uncertainty in simulating the main characteristics of climate over the subtropical regions was generally lower compared with tropical regions of the South American continent. For the present climate simulations driven by global models, the uncertainty in simulating mean temperature and precipitation is more dependent on the regional than on the global model providing the lateral boundary conditions. Finally, ensemble climate- change projections at regional scales allowed exploring the associated range of uncertainties. The remaining challenges in modeling South American climate features are also discussed.