Extended Kalman Filter, Lagrangian Information, and a Two-Tracer Rossby Wave

Amal El Moghraby

University of North Carolina at Chapel Hill

True state observations are the essence in data assimilation. And to avoid collecting redundant information from the velocity field using expensive equipment, the choice of tracer launch coordinates are of great significance. Here we study two passive tracers that are launched sufficiently close in our Eulerian field, close but in dynamically different regions. Although these tracers are initiated close to each other, they will gather different Lagrangian information because of their dissimilar fate. So the question becomes, when the data gathered from the two tracers are assimilated, will it recover similar Eulerian fields, or different ones? The tool we use in our quest to answer this question is the extended Kalman filter, and the velocity field we will consider is the Rossby wave.

This work is in collaboration with Kayo Ide and Christopher K.R.T. Jones.

Last Update: March 25, 2005