HR: 0800h
AN: A31B-06 [Abstracts]
TI: A General-Purpose Ensemble Assimilation Facility: DART
AU: Anderson, J
EM: jla@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000,
United States
AU: Hoar, T
EM: thoar@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000,
United States
AU: * Raeder, K
EM: raeder@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000,
United States
AU: Collins, N
EM: nancy@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000,
United States
AU: Liu, H
EM: hliu@ucar.edu
AF: National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000,
United States
AB:
Although it is trivial to develop an ensemble data assimilation facility for an atmospheric prediction model, the
standard ensemble
algorithms have a number of shortcomings. They are subject to most
error sources that impact more traditional assimilation methods
and also to sampling error from small ensemble sizes. A general
purpose ensemble facility must provide additional adjunct algorithms
that can deal adaptively with these errors. The Data Assimilation
Research Testbed facility developed at NCAR includes a wide range
of novel algorithms. To deal with sampling error, DART includes
a hierarchical Bayesian algorithm that can automatically recommend
a multi-variate, spatially anisotropic localization. Hierarchical
Bayesian algorithms for spatially- and temporally-varying
inflation are also included. A methodology for adaptive
thinning is available to efficiently assimilate observations where they are
dense. Both stochastic and deterministic ensemble filters, as well
as novel hybrid particle/ensemble filter algorithms are available
in the facility. This poster will provide an overview of these
algorithms and examples of their application in global NWP assimilations.
UR: http:www.image.ucar.edu/DAReS/DART
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0343 Planetary atmospheres (5210, 5405, 5704)
DE: 0350 Pressure, density, and temperature
DE: 0394 Instruments and techniques
SC: Atmospheric Sciences [A]
MN: 2007 Joint Assembly