Testing a particle filter to reconstruct climate changes over the past centuries

We implement a data-assimilation method based on a particle filter in the coupled climate model LEVECLIM focusing on decadal to centennial time scales. Several tests are performed with particle filtering using pseudo-observations obtained from a twin experiment with the model, as well as using real-data observations over the last century. These tests demonstrate that it is possible to obtain a model output well correlated with the observations at the large scale at a reasonable cost.