This archive contains answers to questions sent to Unidata support through mid-2025. Note that the archive is no longer being updated. We provide the archive for reference; many of the answers presented here remain technically correct, even if somewhat outdated. For the most up-to-date information on the use of NSF Unidata software and data services, please consult the Software Documentation first.
> Julien, > > That is ok. Here are two I keep getting questions about: > > Horizontal Flux Divergence horizontal scalar flux divergence defined as u*(dp/dx) + v*(dp/dy) + p*(du/dx + dv/dy) > Potential Temperature theta = t * (1000/p)** .286 The url of the user guide may have some information you are looking for: http://www.unidata.ucar.edu/software/idv/docs/userguide/tools/JythonLib.html Yuan > > Thanks! > > Stefan > -- > Stefan Cecelski > Ph.D. Candidate and Graduate Research Assistant > AOSC Department: University of Maryland College Park > 2343 Computer and Space Sciences Building(CSS #224) > 703.801.1370 > address@hidden > > On Fri, May 13, 2011 1:58 pm, Unidata IDV Support wrote: > >> Julien, > >> > >> Before we open another can of worms, I would like to make one request. I > >> have convinced my research group at UMD to use IDV(~5 students). For our > >> research, we NEED to know the formulas we use to calculate variables > >> such > >> as Theta-e, Horizontal Flux Divergence and so forth. There are copious > >> ways of calculating these variables, and literature proves that some > >> ways > >> are more accurate than others. I would like to request that a PDF > >> document, or some literature is created that lists how the derived > >> variables in the IDV are calculated. I understand in the formula editor > >> we > >> can see which variables are going into it, but we need documentation on > >> the actual formulas used. For example, there are at least 3 different > >> ways > >> to calculate Theta-e(Equivalent Potential Temp). It has been shown that > >> the method by Bolton(~1980) is the best. Documentation of which formulas > >> are used are essential for research as in peer-reviewed papers, you must > >> know the formulas, and will be asked about them for the very reasons > >> mentioned above. Thanks in advance. > >> > >> V/R, > >> > >> Stefan > >> -- > > > > > > Stefan, > > > > I believe there is no document available for these formulas. Most > > formulas in the IDV were created by Don in Jython or Java, and I > > believed he referenced those formulas in the GEMPAK. With limit > > resources here, it is unlikely to spend more time to create the > > document for these formulas. However, I can provide more details > > information for specific formula if the request is raised. Sorry > > about the inconvenience. > > > > > > Yuan > > > > Ticket Details > > =================== > > Ticket ID: ZEO-881615 > > Department: Support IDV > > Priority: Normal > > Status: Open > > > > > > > Ticket Details =================== Ticket ID: ZEO-881615 Department: Support IDV Priority: Normal Status: Open