“…They were introduced by Evensen in the seminal article [44] published in 1994, see also [45,46] for a more recent overview. In the last three decades the EnKF methodology has become one of the most used numerical techniques for solving high dimensional forecasting and data assimilation problems in a variety of applications including ocean and atmosphere sciences [1,67,68,58,73], fluid mechanics [14,74,78], image inverse problems [15], weather forecasting [3,4,30,49], environmental and ecological statistics [43,52] and oil reservoir simulations [47,72,82,83,94]. To connect these EnKF techniques with particle filtering methodology for solving high dimensional problems arising in fluid mechanics, we also refer to [59].…”