wrf post processing n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
WRF Post-Processing PowerPoint Presentation
Download Presentation
WRF Post-Processing

Loading in 2 Seconds...

play fullscreen
1 / 49

WRF Post-Processing - PowerPoint PPT Presentation


  • 456 Views
  • Uploaded on

WRF Post-Processing. Wei Wang NCAR/MMM. Outline. NetCDF data NCL General information How is it used in WRF post-processing? How to run it? WRF-to-Vis5D RIP. netCDF Data. netCDF Data. netCDF is one of the data formats chosen for WRF I/O, and is currently supported.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'WRF Post-Processing' - clarke


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
wrf post processing

WRF Post-Processing

Wei Wang

NCAR/MMM

outline
Outline
  • NetCDF data
  • NCL
    • General information
    • How is it used in WRF post-processing?
    • How to run it?
  • WRF-to-Vis5D
  • RIP
netcdf data1
netCDF Data
  • netCDF is one of the data formats chosen for WRF I/O, and is currently supported.
  • What is netCDF?

netCDF stands for Network Common Data Form

netCDF is “an interface to a library of data access functions for storing and retrieving data in the form of arrays.” (http://www.unidata.ucar.edu/)

  • Documentation available at above site.
netcdf data cont
netCDF Data (cont)
  • What are the advantages of using netCDF?
    • Platform-independent (no big_endian, little_endian) – though it may be with some caveat..
    • Many software may already exist which can be used to process netCDF data.
netcdf data cont1
netCDF Data (cont)
  • netCDF utilities available:
    • ncdump reads a netCDF dataset and prints a textual representation of the information in the dataset

e.g. ncdump –h file -- print header (inc. variables in the file)

ncdump –v variable-name file-- print values of the var

    • ncgen generates a netCDF file or a C or FORTRAN program that creates a netCDF dataset
netcdf data cont2
netCDF Data (cont)
  • Other netCDF operators are available from http://nco.sourceforge.net/, which can be used to manipulate data, such as performing grid point averaging, file differencing, and file ‘appending’.
netcdf data cont3
netCDF Data (cont)
  • In WRF system, simple utilities are also available. See for example,

module_wrf_to_v5d_util.F

in wrf2vis5d.tar file.

netcdf data cont4
netCDF Data (cont)
  • Simple calls to access the data. For example,

call get_dims_cdf( file_for_time(1), 'T', &

dims, ndims, debug )

> get dimensions of field T in an array dims

call get_gl_att_real_cdf( file_for_time(1), &

'CEN_LON', cen_lon, debug )

> get attributes from a netCDF file

call get_var_2d_real_cdf( file_for_time(1), &

'XLAT', xlat, dims(1), dims(2), 1, debug)

> get the 2D field XLAT (similar call for a 3D field)

ncl in wrf

NCL in WRF

Slides contributions from Bill Skamarock and Ethan Alpert (NCAR/SCD)

what is ncl
What is NCL?
  • NCL stands for NCAR Command Language
  • NCL is an interpreted programming language
    • Array based algebraic operators
    • Support netCDF data
    • Wide variety of graphics capabilities:
      • Maps, Contours, XY, Vectors, Streamlines, labelbars, text, tickmarks as well as line, marker and polygon primatives
      • Output to X, NCGM, PostScript
what is ncl1
What is NCL?
  • NCL is available on most UNIX platforms
  • NCL can run in batch or interactive mode
    • Interactive mode has command history and command line editing
  • Many useful functions and procedures
  • Code integration tool (ability to import FORTRAN)
  • Pre-compiled binaries are free.
downloading ncl
Downloading NCL
  • Go to:
    • http://ngwww.ucar.edu/ncl/download
  • Read and agree to GPL license
  • Fill out short registration form
  • Download binaries
    • Precompiled versions exist for:
      • IBM RS6000, DEC Alpha, Sun Solaris, RedHat Linux, SGI IRIX, Alpha running RedHat Linux, and Mac running OSX
important resources for using and learning ncl
Important resources forusing and learning NCL
  • NCL home page:
    • http://ngwww.ucar.edu/ncl
  • Contains links to documentation, examples, FAQ, ncl-talk email list, and update information
getting started using ncl gsun
Getting Started Using NCL (GSUN)
  • Getting Started Using NCL (GSUN)
    • http://ngwww.ucar.edu/ngdoc/ng/ug/ncl/gsun/
    • Intended for users with little or no NCL experience
    • Some programming language knowledge is assumed
    • Learning by example concept
    • Starts with basics and builds from there
    • Provides a set of simple functions written in NCL to be used by new users instead of NCL’s object oriented Graphics interface
    • The “Beyond the Basics” section covers incorporating FORTRAN into NCL
additional resources for using and learning ncl
Additional resources for using and learning NCL
  • NCL users email list
    • http://ngwww.ucar.edu/ncl-talk/
    • Email list devoted to NCL discussion
    • Read by NCL developers and support staff
  • Examples page
    • http://ngwww.ucar.edu/ncl/examples.html
  • CCSM NCL page for additional examples
    • http://www.cgd.ucar.edu/csm/support
ncl for wrf model data
NCL for WRF Model Data
  • The NCL scripts for plotting WRF model output are our first attempt at producing plots for use in our development efforts.
  • They can do vertical interpolation (so one can plot data on pressure levels), skew-T, and vertical cross-sections.
  • They currently plot model output variables plus a few diagnostic variables, such as SLP, dew point temperature, and RH.
  • Can work with multiple input files and subdomains
ncl for wrf model data1
NCL for WRF Model Data
  • Advantage:
    • NCL reads WRF data directly
    • Can make simple plots quickly
    • Easy to make difference plots
  • Disadvantage:
    • Initial learning may be slow
    • Array computation may be slow unless using Fortran
downloading
Downloading
  • From wrf-model.org web site:

http://www.mmm.ucar.edu/wrf/users/download.html

  • tar file: wrf_ncl.tar
  • After untar, one finds directory

WRF_NCL/README_FIRST

README_NCL

eh/

em/

wrf ncl em directory
WRF_NCL/em/ directory

make_ncl_fortran

make_ncl_fortran.alpha

make_ncl_fortran.rhlinux

make_ncl_fortran.ibm

make_ncl_fortran.sun

wrf_user_fortran_util_0.f

wrf_user_fortran_util_0.o

wrf_user_fortran_util_0.so

wrf_user_fortran_util_0_W.c

wrf_user_fortran_util_0_W.o

wrf_plot.ncl

wrf_user_mass.ncl

skewt_func.ncl

gsn_code.ncl

wrf_em_b_wave.ncl

wrf_em_hill2d.ncl

wrf_em_qss.ncl

wrf_em_squall_2d_x.ncl

wrf_em_squall_2d_y.ncl

wrf_em_sfc.ncl

wrf_em_slp.ncl

wrf_em_qv.ncl

wrf_em_the.ncl

wrf_em_real.ncl

wrf_em_real_input.ncl

Scripts to build fortran shared library

Created by fortran build

NCL functions and procedures used by the plotting scripts

Plotting scripts

wrf plot ncl
wrf_plot.ncl
  • Contains functions and procedures that are used by all ncl plotting scripts:
    • maps
    • contour and color-filled plots
    • vectors
  • To include it in a ncl script:

load “wrf_plot.ncl”

skewt func ncl
skewt_func.ncl
  • Functions for making skew-T plots
  • Load near the top of the ncl plotting script
wrf user mass ncl
wrf_user_mass.ncl
  • This is where a user may choose to add new variables for plotting
  • Can be used to obtain native model output variables, or diagnose new variables
  • Make Fortran calls to routines in wrf_fortran_user_util_0.f
  • Use existing examples inside the file as templates for adding new variables
wrf fortran user util 0 f
wrf_fortran_user_util_0.f
  • Contains Fortran routines for diagnostic calculations
  • Fortran routines are stubbed with ‘NCLFORTSTART’ and ‘NCLEND’.

e.g.

C NCLFORTSTART

subroutine compute_rh(qv,p,t,rh,nx,ny,nz)

implicit none

integer nx, ny, nz

real qv(nx,ny,nz),p(nx,ny,nz),

& t(nx,ny,nz),rh(nx,ny,nz)

C NCLEND

how to generate shared object file
How to generate shared object file?
  • makefiles exist to create shared object file from Fortran code for Alpha, Linux, IBM and Sun: e.g.

make_ncl_fortran.alpha

make_ncl_fortran.linux

  • Type

make_ncl_fortran.alpha wrf_user_fortran_util_0

-> creates wrf_user_fortran_util_0.so

  • For other machines, edit one of the make files
how to run ncl
How to run NCL?
  • Type the following to run (batch example)

ncl < wrf_em_real.ncl

  • To run NCL interactively, type

ncl

then enter appropriate ncl commands

  • Output from ncl can be in metacode, postscript, or on the screen
wrf to vis5d

WRF-to-VIS5D

Wei Wang

NCAR/MMM

what does it do
What does it do?
  • Convert WRF model output data in netCDF to Vis5D format.
  • Vis5D is a three-dimensional visualization software
  • Vis5D is free and can be downloaded from

http://www.ssec.wisc.edu/~billh/vis5d.html

downloading1
Downloading
  • From wrf-model.org web site:

http://www.mmm.ucar.edu/wrf/users/download.html

  • tar file: wrf2vis5d.tar
  • After untar, one finds directory

WRF2VIS5D/README

eh/

em/

wrf2vis5d em directory
WRF2VIS5D/em directory

The following files exist in the directory:

Makefile

README

module_wrf_to_v5d_util.F

module_wrf_to_v5d_netcdf.F

v5df.h

wrf_to_v5d.F

wrf_v5d_input

how to compile and run
How to compile and run?
  • Type the following to compile:

make wrf_to_v5d

  • Edit command line input file:

wrf_v5d_input

  • Type the following to run:

wrf_to_v5d wrf_v5f_input vis5d-filename

  • Type the following to view Vis5D data:

vis5d vis5d-filename

file wrf v5d input
File wrf_v5d_input

-1 ! number of times to put in vis5d file, negative means ignore the times

2000-01-24_18:00:00

U ! variable list for vis5d file, indent one space to skip

V ! first five in list are special variables (diagnosed)

W

THETA

TK

TC

QVAPOR

QCLOUD

QRAIN

RAINC

TSK

end_of_variable_list

Space at the beginning: Not processed

file wrf v5d input cont
File wrf_v5d_input (cont.)

wrfout_d01_000000 ! WRF output file name

end_of_file_list

-1 ! specify v5d vertical grid 0=cartesian, -1=interp to z from lowest h, >1 list levels (z) desired in vis5d file

1 1.

2 2.

3 3.

4 4.

5 5.

6 6.

7 7.

8 8.

9 9.

10 10.

rip4 read interpolate plot version 4

RIP4Read/Interpolate/Plot (Version 4)

Slides contribution from Dave Gill

general information
General Information
  • Written by Mark Stoelinga of UW
  • Requires NCAR Graphics low-level routines – freely available from http://ngwww.ucar.edu
  • Originally written for MM5 input and output, and recently rewritten and generalized to include WRF
  • Horizontal plots on native model coordinate, pressure, height, q, qe, or PV surfaces
  • Vertical cross sections on native model coordinate, pressure or log pressure, p, height, q, qe, or PV as coordinate surface
general information cont
General Information (cont)
  • Skew-T/log p soundings specified at grid points or lat/lon, optional hodographs and sounding quantities
  • Forward and backward trajectories
  • Generate input data for Vis5D
  • Large number of diagnostic fields (> 100)
  • Allow users to tailor the graphics
  • Currently works for real-data simulation data only
  • Detailed documentation
downloading program tar file
Downloading Program tar File
  • RIP program tar file can be downloaded from

http://www.mmm.ucar.edu/wrf/users/download.html

    • html documentation included
compiling rip on your machine
Compiling RIP on Your Machine
  • Uncompress and untar the file: RIP4.TAR.gz
  • Edit src/Makefile to define paths to netCDF library and include file on your computer:

NETCDFLIB and NETCDFINC

  • make <machine type> (it’ll make suggestions)

e.g.

make linux

compile RIP on a Linux computer

ripdp wrf
RIPDP_WRF
  • ripdp_wrf: where ‘dp’ stands for Data processing
  • ripdp_wrf converts WRF netCDF data into RIP input format (format described in the document)
  • ripdp_wrf puts each variable at each time into a separate file – expect to see LOTS of files
running ripdp wrf
Running ripdp_wrf
  • Set environment variable RIP_ROOT to where RIP is installed and where RIP utility files reside.

e.g. setenv RIP_ROOT /users/wrfhelp/RIP4

  • Run ripdp_wrf:

ripdp_wrf [–n namelist-file] <model_data_name> [basic/all] \

<input_file1 input_file2>

namelist-file optional

  • Make a directory for the files, use that as part of the model_data_name. e.g.

./storm_case/test1

ripdp namelist
RIPDP namelist
  • Use namelist-file (example in ripdp_sample.in) to add control
    • select processing times
    • discard fields if ‘all’ is selected on the command line
rip uif
RIP UIF
  • UIF : User Input File (example in rip_sample.in)
  • First section is a list of general parameters (namelist format)
  • Second section is a Plot Specification Table (or PST)
rip namelist
RIP namelist
  • Use namelist to control
    • processing times, intervals
    • title information
    • text quality on a plot
    • whether to do time series, trajectory, or to write output for Vis5D
  • Full explanation for namelist variables is available in the user document
rip uif1
RIP UIF

&userin

....

/

&trajcalc

....

/

===============================================

--------- Plot Specification Table ------------

===============================================

Plot specification line (PSL)

PSL: plot spec settings (PSS)

PSL: PSSs

===============================================

namelist

frame specification group(FSG)

rip pst fsg psl
RIP PST FSG PSL
  • PST – Plot Specification Table
  • First line is “====“, next 2 lines ignored
  • Each group separated by subsequent “===“ is a FSG (Frame Specification Group)
  • Each line within an FSG is a PSL (Plot Specification Line)
  • An FSG with 3 PSLs will have 3 plots on one frame
rip pss
RIP PSS
  • Each PSL contains several PSSs (Plot Specification Settings) (see example next)
    • keyword=value[,value,value]
    • keyword is a 4-char identifier
    • All PSSs within a PSL are separated by “;”
    • Last PSS on a PSL has no “;”
    • “>” at the end of the line means the PSL continues
    • Comments require a “#”
an example of pst
An example of PST

========================================================

feld=tmc; ptyp=hc; vcor=s; levs=b1; cint=2; cmth=fill;>

cosq=-32,light.violet,-24,violet,-16,blue,8,green, > 0,yellow,8,red,16,orange,24,brown,32,light.gray

feld=slp; ptyp=hc; cint=2; linw=2

feld=uuu,vvv; ptyp=hv; vcmx=-1; colr=white; intv=5

feld=map; ptyp=hb

feld=tic; ptyp=hb

========================================================

* Bold letters indicate ‘keywords’

running rip
Running RIP
  • Edit the UIF (rip-execution-name.in)
  • Type the following to run:

rip [-f] model-data-set-name rip-execution-name

  • model-data-set-name is from RIPDP_WRF
  • rip-execution-name is unique name, for output, metacode and UIF

e.g. rip-execution-name.cgm

  • View the .cgm file using NCAR Graphics utility

idt rip-execution-name.cgm

other notes
Other Notes
  • Appendix A contains a list of keywords for PSS
  • Appendix B has a long list of fields that can be plotted by RIP
  • New fields may be added
  • Currently works with wrfout files only, and with real-data