A4 - African and Asian Monsoon Margins
The project aims at understanding the sensitivity and the variability of the tropical precipitation over the African and Asian monsoon margins, which the livelihood and well-being of a large part of the human population depend on. We will be able to assess the realism of state-of-the-art climate models in simulating monsoon dynamics and their changes, including the influence of internal climate variability. We will compare simulations, palaeo-reconstructions, and instrumental observations. We focus on rapid climate changes such as the 8.2k-event and the termination of the African Humid Period some 5000 years ago, as well as the recent global warming with an outlook on possible future climate changes.
We expect a breakthrough in our understanding of past monsoon variability from globally coupled climate system simulations at very-high resolution that explicitly represent deep convection in the tropics, mesoscale ocean eddies and terrestrial processes in steep terrain. Large single-model ensembles of transient simulations with order of 100km resolution will foster our understanding of the internal variability of the monsoon margins and their transient interaction within the global monsoon system. Transient high-resolution numerical simulations, becoming possible owing to new developments in high-performance computing (project HPC), will be combined with new high-resolution reconstructions from marine records.
By modeling sediment cascades, using an advanced process based approach of forward proxy modeling, we will reconstruct past precipitation pattern relative to orographic features thereby tracking sediment pathways from source to sink, which can be evaluated against the marine proxy records. By comparing palaeo simulation and reconstruction, we will be able to assess the realism of climate models of the last generation in simulating monsoon dynamics and thus constrain the uncertainty of projections regarding possible and plausible changes in the African and Asian monsoon margins.
The project contributes to the overarching CLICCS question by constraining the uncertainty of projections regarding possible and plausible changes in the African and Asian monsoon margins and by providing information on internal variability of tropical precipitation that is needed to determine aleatoric uncertainties in one of the world's most populous regions.