Ensemble Kalman Filter and 4D-Var Intercomparison with

filter4dTable-top filters can remove contaminants from tap water – but are they really necessary, and could they cause unintentional harm? If she can help it, Shima Chin-SeeTechnical Memorandum No.347 1 Developments in 4D-Var and Kalman Filtering by Mike Fisher and Erik Andersson Abstract We discuss the status and the performance of the reduced rank