I used ARWpost to extract wrf parameter and have:
U 29 0 x-wind component (m s-1)
V 29 0 y-wind component (m s-1)
W 29 0 z-wind component (m s-1)
PH 29 0 perturbation geopotential (m2 s-2)
PHB 29 0 base-state geopotential (m2 s-2)
T 29 0 perturbation potential temperature (theta-t0) (K)
MU 1 0 perturbation dry air mass in column (Pa)
MUB 1 0 base state dry air mass in column (Pa)
NEST_POS 1 0 - (-)
P 29 0 perturbation pressure (Pa)
PB 29 0 BASE STATE PRESSURE (Pa)
P_HYD 29 0 hydrostatic pressure (Pa)
Q2 1 0 QV at 2 M (kg kg-1)
T2 1 0 TEMP at 2 M (K)
TH2 1 0 POT TEMP at 2 M (K)
PSFC 1 0 SFC PRESSURE (Pa)
U10 1 0 U at 10 M (m s-1)
V10 1 0 V at 10 M (m s-1)
QVAPOR 29 0 Water vapor mixing ratio (kg kg-1)
QCLOUD 29 0 Cloud water mixing ratio (kg kg-1)
etc.
Is there a way to compute sea level pressure using grads, matlab, R etc.. from these available variables.
you can use NCL, follow the following link
https://www.ncl.ucar.edu/Document/Functions/Built-in/wrf_slp.shtml
let me know if you do not understand
I don't know if I can use parameters from ARWpost ? because and unfortunately to save space after using ARWpost I deleted the wrfout files from the simulation.
Abdoulaye
Well, as ARWpost has limited functionality. I would suggest you to re-run the model to get the sea-level pressure. you also did not mentioned simulation duration and forcing and boundary data. the limitations of ARWpost are given here http://www2.mmm.ucar.edu/wrf/OnLineTutorial/Graphics/ARWpost/
Attached is MATLAB subroutine written by me which calculates sea-level pressure from the conventional variables saved by WRF. The algorithm is based on the MM5/INTERPB program (http://www2.mmm.ucar.edu/mm5/documents/MM5_tut_Web_notes/INTERPB/interpb.htm).
Dear Ivan, thank you very much for sharing your matlab routine to compute sea level pressure. I'll see if all needed parameters by the function are available in the output I got from ARWpost hoping that It don't expect the direct wrf output. If so, I'll redo the run as kindly suggested by Shahzad .
In case of other kind of problem with the function I'll certainly come back to you.
Hi Ivan and Shahzad, I managed to rerun the model and produced wrfout, I tested Ivan routine which generates slp values. My need is have the slp written in a file in netcdf format for postprocessing. With ncl i am wondering if Shahzad you have a sample example I could replicate for my case. Thank you all again
I think you can use CDO for doing that , there is a way that you can process sea level pressure for surface variable may be temperature or any surface variable like U and V.
Ivan Kovalets
In your function, I am unable to find SLP for different time steps. Example: PSLV= Lon X Lat
I want to have a format like: Lon X Lat X Time
I am very new to loops. Will you help me with the addition of the timestep in your function.
Depending on options in wrf namelist file, the variables calculated at different time steps could be stored in a single file, or in different files. This script processes wrf files in which variables are stored only for a single time step, not for many time steps (represented by index 4). Therefore if somebody wants to process wrf files in which variables for many time steps are stored, then this script needs to be adapted.
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