Changes between Initial Version and Version 1 of ToolsAndUtilities/Sfvp

29/04/13 10:02:44 (7 years ago)

Content copied over from climate wiki


  • ToolsAndUtilities/Sfvp

    v1 v1  
     1= SFVP = 
     3`sfvp` is a program that can calculate the Stream function and numerous other fields from basic U and V wind components (Please note: AVAILABLE ONLY FOR UNIVERSITY OF READING Researchers). To get access to the `sfvp` executable run 
     5setup umtools 
     7Running `sfvp` without arguments will print this help information: 
     9These are the instructions for sfvp 
     11Usage:sfvp fn1 vn1 fn2 vn2 opfn 
     14Calculates streamfunction and velocity potential 
     15on the sphere, given inputs of the two velocity 
     16components on the UM velocity grid 
     20sfvp outputs: 
     30stream function 
     31velocity potential 
     32tvor (?) 
     33tdiv (?) 
     36== Notes == 
     38 * Input data files need to be in netCDF format. 
     40 * `sfvp` only really likes 4d files. To convert a 3d file to a 4d file (by inserting a dummy axis) use `~dan/idl/` 
     42 * I've semi-automated the process of calculating `seasonal_means` and `ensemble_mean_seasonal_means` from the output of `sfvp`. The script that does this lives at `/home/dan/data/UM_DATA/SFcalc` 
     44 * If you get this error: `POISSON ERROR - WRONG LATITUDE FROM NCNS2G; ABORT` Then it is probably because your lattitude axis is the wrong way around. `sfvp` seems to prefer positive to negative, rather than vice versa. You can fix this by transforming the axis using `xconv`. Using `xconv` to do this may interpolate the data and change the latitude coordinate values, a better way is to use the nco tool [ ncpdq] this will invert the latitude axis without interpolation or changing the coordinate values. An example of ncpdq usage is, `ncpdq -a -latvar`, where `latvar` is the name of the netCDF latitude dimension.