181 1996 Jarmo Rantakokko jarmo@tdb.uu.se Strategies for parallel variational data assimilation Abstract The prospects to parallelize a variational data assimilation scheme from the starting point of an existing parallel forecast model and its adjoint equations have been investigated. Three parallelization strategies to do the implementation and two partitioning algorithms to compute data distributions have been suggested. Numerical simulations of the parallelizations show that the strategies and the partitioning algorithms can be combined to perform well on shared memory respectively distributed memory machines and that they give better results than direct use of standard parallelization methods.