Re: [gembud] GEMPAK going away in 3-5 years? (IDV discussion)

I can't help but comment that these sorts of issues have been around for a long time as well as a solution. A host of artifacts are likely with such grids from WRF and other NWP codes for a variety of reasons, which I can outline. Granted, the impact will depend on the specific model configuration and data (e.g., wind field near the surface in a high-resolution nest vs. a moisture field in an upper layer at low resolution with radiation processes dominating). Some are introduced by the conversion process while others by the choice of contouring or other realization algorithm. They are exacerbated by nested grids. We developed a solution to this about 17 years ago in Data Explorer, which has been available in open source since 1999 (www.opendx.org). You simply operate directly on the native grids and bypass these issues (i.e., because they are directly supported by the internal data model and processing algorithms). I've attached a very simple example, which is screen dump from a protoype WRF-ARW viewer I built a few years ago with DX. The 3d viewing coordinate system is also native to WRF. In addition to avoiding the various artifacts, the intermediate processing step is unnecessary. 

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Lloyd A. Treinish
Project Scientist, Big Green Innovations
IBM Systems & Technology Group
1101 Kitchawan Road, Yorktown Heights, NY 10598
914-945-2770, lloydt@xxxxxxxxxx
http://www.research.ibm.com/people/l/lloydt/
http://www.research.ibm.com/weather/DT.html
http://www.ibm.com/technology/greeninnovations

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