My colleagues Alberto Carrassi, Laurent Bertino, Geir Evensen and I have worked on an overview of data assimilation techniques for the climatologists. This corresponds to an invited overview paper from WIREs Climate Change and edited by Eduardo Zorita and Mike Hulme.

We have tried to strike a balance between a technical review (data assimilation is a mathematical subject) and a verbose and descriptive report. This 50-page review is fairly complete although we had to leave a few subtopics out. We discuss of the probabilistic view on data assimilation, of the Kalman and variational approaches, of the ensemble Kalman filter, of the ensemble-variational methods, and a variety of selected topics. We also open the overview to fast developing subjects such as particle filter for the geoscience models and coupled data assimilation, both of great relevance for climate studies.

This overview has been published in WIREs Climate Change. It is entitled Data assimilation in the geosciences: An overview of methods, issues, and perspectives.