calc_WAF

Wave Activity Flux

Usage:
        calc_waf.py [-M] [-h] {u_file} {u_clim_file} {u_name}
    {v_file} {v_clim_file} {v_name} {zg_file} {zg_clim_file} {zg_name}
    {output_wafx_file} {output_wafy_file} {hPa} {syear} {eyear} {smon} {emon} {sday} {edy} {cyear}

Options
        -M -> Display this on-line manual page and exit
        -h -> Display a help/usage message and exit

Description
        Takes as input the u wind, v wind, geopotential height (zg)
    and their climatologies and outputs the x and y
    components of the wave activity flux.

Assumptions by tnf_xy_onelevel.f90 script (i.e. hard wired elements)
    The WAF Fortran code is hard wired to produce output on a
    global 2.5 by 2.5 deg grid (i.e. 73 lats, 144 lons).
    It is hard wired that the input data is from the 250 hPa level.
    It is assumed that the input data is three dimensional (time, lat, lon).

Python (cal_WAF.py) script assumptions and capability
    It assumes the global data is passed as input with any degree resolution, 
    which will be going to be converted to 2.5x2.5 deg. 
    User can choose their desired pressure level from input files.
    User can choose their desired time (range of dates) from the input files, 
    it assumes that daily input files are being passed as input but works well for monthly data also.


Reference
    Takaya, K., Nakamura, H., 2001.
        A formulation of a phase-independent wave-activity flux
    for stationary and migratory quasi-geostrophic eddies
    on zonally-varying basic flow. J. Atmos. Sci., 58, 608-627

Environment
        Need to load cdat

    Example by ([email protected], [email protected])
    /opt/cdat/bin/cdat calc_waf.py
     era_interim_u_dailyavg_19820101_20171031.nc
     era_interim_u_daily_climatology_1982_2010_cdo.nc
     u
     era_interim_v_dailyavg_19820101_20171031.nc
     era_interim_v_daily_climatology_1982_2010_cdo.nc
     v
     era_interim_z_dailyavg_19820101_20171031.nc
     era_interim_z_daily_climatology_1982_2010_cdo.nc
     z
     WAF_DATA/wafx_200hPa_%s.nc     # %s will be replaced with year
     WAF_DATA/wafy_200hPa_%s.nc     # %s will be replaced with year
     200                            # extract particular pressure level
     1982                           # start year of needed data from input data
     2017                           # end year of needed data from input data
     3                              # start month of needed data from input data
     6                              # end month of needed data from input data
     1                              # start day of start month of needed data from input data
     30                             # end day of end month of needed data from input data
     2010                           # climatology year of climatology input files


Purpose : Purpose of the extra 8 arguments to fulfil the extracting time and level constraints from the input files
          and create the year wise output wafx, wafy files. For example, in the above example arguments are given to 
	  extract MAMJ months, daily data from 1982-2017 years input and climatology year is 2010 (which was created 
	  by cdo from year 1982-2010).
Author
        Damien Irving, 12 Oct 2012.
Updated by :
        Arulalan.T 29 Jan 2018. <[email protected]>
        Works on latest UV-CDAT version as on 2018.
        As per fortran script, both raw data and climatology data time length should be same.
        So we are splitting the calc_waf calculation of every year in a loop.
Bugs
    Please report any problems to: [email protected]