Title: Quantifying the role of observations in ocean state estimation

Authors: Brian Powell (University of Hawaii)

In the past decade, variational methods have been used by Numerical Weather Prediction centers around the world, and are now becoming a component of ocean modeling. In solving the state-estimation problem, I also compute the dynamical covariance between the observations and the model, which provides an estimate of the observability of the ocean. The impact of each observation can be assessed to compare the relative importance of different observations to the controllability of the state estimate. I examine the observational impact on two dynamically distinct cases in the ocean: the Hawaiian Islands and the North Atlantic. Despite their relatively small size, the Hawaiian islands have a significant impact upon the atmospheric and oceanic circulations of the northern, sub-tropical Pacific. The North Atlantic ocean is a crucial component of the Earth's poleward heat transport, bringing significant heat to Europe and the sub-arctic region. State estimation experiments from three years to 13 years in Hawaii and the Atlantic, respectively, reveal interesting contrasts on which observations provide information to the ocean.

GMAO Head: Michele Rienecker Global Modeling and Assimilation Office NASA Goddard Space Flight Center

Curator: Nikki Privé Last Updated: May 27 2011