[GTP] NCAR MMM seminar

[Silvia Gentile]

**

For questions please contact MMM SEMINAR COORDINATOR:  Jielun Sun, 
303-497-8994

jsun at ucar.edu http://www.mmm.ucar.edu/sem/seminars.html

*
Development of Wavelet Methodology for WRF Data Assimilation*

 

 

*/Aimé Fournier/*

/National Center for Atmospheric Research/

/Mesoscale and Microscale Meteorology Division/

/Boulder, CO/

/ /

 

This work aims at improved computation of covariances and of multiscale structures such as clouds, in the Weather Research and Forecasting (WRF) data-assimilation (WRFDA) system, in particular the horizontal factor of the control-variable transform.  Better representation can be achieved in the horizontal transform by wavelet-compression techniques that have been proven in many other applications.

 

In this work, two past obstacles to effective incorporation of wavelets in limited-area models such as WRF are resolved: isometric-injective (i.e., energy preserving, left-invertible) wavelets avoid boundary-condition assumptions at any scale; and these wavelets can be applied to non-dyadic data lengths.  A summary technical description of these improved wavelets and their implementation into WRFDA is presented.  By retaining only a diagonal background-covariance matrix in wavelet space, appropriate

heterogeneity is obtained for the model-space covariances.

 

A second wavelet application is to partition observation error into a part due to poor representation (e.g., too-coarse resolution), and a residual, using a novel criterion in wavelet space.  Other methods to construct inhomogeneous anisotropic covariance models are cited, and other potential technical improvements are discussed.

 

 

*_ _*

*Thursday**, 28 October 2010, 3:30 PM*

Refreshments 3:15 PM

NCAR-Foothills Laboratory

3450 Mitchell Lane

Bldg 2 Auditorium, Room 1022

-- 
Silvia Gentile
NCAR IMAGe
1850 Table Mesa Drive
Boulder, CO 803035
www.image.ucar.edu