WWRP/THORPEX WORKSHOP on 4D-VAR and
ENSEMBLE KALMAN FILTER INTER-COMPARISONS
BUENOS AIRES - ARGENTINA, 10-13 NOVEMBER 2008
Hosted by the
School of Sciences of the University of Buenos Aires and the
Center for Atmospheric and Ocean Research CIMA/CONICET
Dr. Luc Fillion, Environment Canada, CAN
Dr. Eugenia Kalnay, University of Maryland, USA
Dr. Ronald M. Errico, GEST/NASA, USA
Dr. Fuqing Zhang, Texas A&M University, USA
Dr. Kamal Puri, Bureau of Meteorology Research Centre, Australia
LOCAL ORGANIZING COMMITTEE
Dr. Mario Nuñez,
Dr. Celeste Saulo, Dr. Carolina Vera,
Centro de Investigaciones del Mar y la Atmosfera and
Universidad de Buenos Aires
Four dimensional variational data assimilation (4D-Var) introduced in the mid 80's, has grown from an initial
theoretical formulation based on optimal control theory, to highly complex and successful implementations in
operational numerical weather prediction (NWP) centers around the world.
About a decade after the introduction of 4D-Var, an original suggestion made by Evensen culminated with
an attractive data assimilation procedure now known as the Ensemble Kalman Filter (EnKF).
In the last decade, an increased interest in this approach has led to significant improvement in its
theoretical foundations and practical implementations. Although 4D-Var and EnKF can be written in similar symbolic form,
their specific theoretical and implementation limitations are of high interest and work is needed to clarify
the methodologies in the face of complex operational implementations that are currently envisaged.
The primary purpose of the workshop is to encourage scientific discussions for a better understanding of the two data
assimilation methods by current researchers in the field and to stimulate interest of younger scientists.
The workshop will also focus on intercomparisons of the two methods in various contexts, incorporating both theoretical
considerations as well as practical implementations, and with a special emphasis on atmospheric data assimilation.
The discussions should therefore provide a solid scientific basis for supporting practical decisions eventually to be taken
by meteorological agencies concerned.
The Workshop will be preceded by a 2 week intensive
course on data assimilation for Latin
American students and researchers
Dr. LUC FILLION
Division de la Recherche en Meteorologie,
Environment Canada. Dorval, Qc, Canada, H9P 1J3
Dr. EUGENIA KALNAY
Department of Atmospheric and Oceanic Science,
University of Maryland.College Park, MD 20742
Telephone: 301 405-5370