It is our pleasure to invite you to participate in the Third Stratospheric Processes and their Role in Climate  (SPARC) Data Assimilation (DA3) Workshop.  The first workshop was held in Baltimore in June 10-12, 2002 and the second in Florence, Italy on June 4-6, 2003. 

The goals of the present workshop are to (1) present work on and encourage discussion of upper tropospheric, stratospheric and mesospheric assimilation of chemical and dynamical variables, (2) identify issues that can be addressed by the working group, and (3) consider the need for an intercomparison project of stratospheric ozone analyses and, if the need is clear, to initiate this work.  Presentations on all aspects of data assimilation for the upper troposphere, stratosphere and mesosphere are invited.  Specific themes include:

(1) Representation of dynamical aspects of analyses such as stratospheric sudden warmings, tropical winds and the QBO,
(2) Quasi-horizontal mixing properties of analysed winds, and representation of the sub-tropical mixing barrier,
(3) Diagnosis of long time scale errors of analysed winds (e.g. diabatic circulation),
(4) Analysis of water vapour in the tropical tropopause region,
(5) New developments in data assimilation and retrieval theory,
(6) Assimilation of constituent observations from research and operational satellites,
(7) Coupling of chemical and meteorological data assimilation systems.

The workshop will be held at the Banff Centre in Banff, Canada, which is about a 90 minute drive from Calgary.  There are non-stop flights to Calgary from many US airports as well as London and Frankfurt.

This workshop will overlap by one day with a SPARC Workshop on Stratospheric Winds. Presentations of relevance to both workshops will occur on the overlapping day.  Participants are invited to attend either or both workshops, for any number of days.  There will be a daily rate of $203 CDN which covers accommodation, all meals, taxes and gratuities.  There may be a small meeting fee to cover coffee breaks and, possibly, a banquet.  Note that $1 CDN = $0.85 US = $0.65 EURO, approximately.

Saroja Polavarapu, Meteorological Service of Canada
Alan O'Neill, University of Readin
SPARC-DA Workshop Organizers