Re: interpolating hybrid height coordinate to pressure level

From: Karin Meier-Fleischer <meier-fleischer_at_nyahnyahspammersnyahnyah>
Date: Fri May 23 2014 - 07:08:20 MDT

Hi,

there was an email from Dennis Shea last year which explains how to convert the
hybrid height levels into pressure levels using the variable pres (in CMIP5 it's plev)
and the NCL function linint_n_Wrap :

http://www.ncl.ucar.edu/Support/talk_archives/2013/1125.html

Hope this will help you,
Karin

Am 23.05.2014 um 13:55 schrieb jagan TNAU <jagan@tnau.ac.in>:

> Dear all,
>
> I have cmip5 HadGEM2-ES netcdf file which has z axis as hybrid height coordinate (meters). I want this to be interpolated to required pressure level. I looked the Vertical interpolation section but I did not find an example of this kind. Please find below the ncdump output for netcdf file to be interpolated. Is there any NCL function which can accomplish this kind of interpolation or any other it can be done.
>
> I request NCL users help.
>
> --------------------------------------------------------------------------------------------------------------
> netcdf va_6hrLev_HadGEM2-ES_rcp45_r1i1p1_200512010600-200603010000 {
> dimensions:
> time = UNLIMITED ; // (360 currently)
> lev = 38 ;
> lat = 144 ;
> lon = 192 ;
> bnds = 2 ;
> variables:
> double time(time) ;
> time:units = "days since 1859-12-01" ;
> time:calendar = "360_day" ;
> time:axis = "T" ;
> time:long_name = "time" ;
> time:standard_name = "time" ;
> double lev(lev) ;
> lev:bounds = "lev_bnds" ;
> lev:units = "m" ;
> lev:axis = "Z" ;
> lev:positive = "up" ;
> lev:long_name = "hybrid height coordinate" ;
> lev:standard_name = "atmosphere_hybrid_height_coordinate" ;
> lev:formula = "z(k,j,i) = a(k) + b(k)*orog(j,i)" ;
> lev:formula_terms = "a: lev b: b orog: orog" ;
> double lev_bnds(lev, bnds) ;
> lev_bnds:formula = "z(k,j,i) = a(k) + b(k)*orog(j,i)" ;
> lev_bnds:standard_name = "atmosphere_hybrid_height_coordinate" ;
> lev_bnds:units = "m" ;
> lev_bnds:formula_terms = "a: lev_bnds b: b_bnds orog: orog" ;
> double b(lev) ;
> b:long_name = "vertical coordinate formula term: b(k)" ;
> float orog(lat, lon) ;
> orog:standard_name = "surface_altitude" ;
> orog:long_name = "Surface Altitude" ;
> orog:comment = "height above the geoid; as defined here, \"\"the geoid\"\" is a surface of constant geopotential that, if the ocean were at rest, would coincide with mean sea level. Under this definition, the geoid changes as the mean volume of the ocean changes (e.g., due to glacial melt, or global warming of the ocean). Report here the height above the present-day geoid. Over ocean, report as 0.0" ;
> orog:units = "m" ;
> double b_bnds(lev, bnds) ;
> b_bnds:long_name = "vertical coordinate formula term: b(k+1/2)" ;
> double lat(lat) ;
> lat:bounds = "lat_bnds" ;
> lat:units = "degrees_north" ;
> lat:axis = "Y" ;
> lat:long_name = "latitude" ;
> lat:standard_name = "latitude" ;
> double lat_bnds(lat, bnds) ;
> double lon(lon) ;
> lon:bounds = "lon_bnds" ;
> lon:units = "degrees_east" ;
> lon:axis = "X" ;
> lon:long_name = "longitude" ;
> lon:standard_name = "longitude" ;
> double lon_bnds(lon, bnds) ;
> float va(time, lev, lat, lon) ;
> va:standard_name = "northward_wind" ;
> va:long_name = "Northward Wind" ;
> va:comment = "on all model levels" ;
> va:units = "m s-1" ;
> va:original_name = "mo: m01s00i003" ;
> va:history = "2010-09-08T14:00:25Z altered by CMOR: replaced missing value flag (-1.07374e+09) with standard missing value (1e+20)." ;
> va:missing_value = 1.e+20f ;
> va:_FillValue = 1.e+20f ;
> va:associated_files = "baseURL: http://cmip-pcmdi.llnl.gov/CMIP5/dataLocation gridspecFile: gridspec_fx_HadGEM2-ES_rcp45_r0i0p0.nc" ;
> -------------------------------------------------------------------------------------------------------
>
> --
> With regards
>
> Dr.R.Jagannathan
> Professor of Agronomy
> Agro Climate Research Centre
> Tamil Nadu Agricultural University
> Coimbatore - 641 003 India
>
> PHONE: Mob: +91 94438 89891
>
> DO NOT PRINT THIS E-MAIL UNLESS NECESSARY. THE ENVIRONMENT CONCERNS US ALL.
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_______________________________________________________________________
Dipl. Geophys. Karin Meier-Fleischer
Application Support, Visualization

Deutsches Klimarechenzentrum GmbH E-Mail:
meier-fleischer@dkrz.de

Bundesstrasse 45a Internet: http://www.dkrz.de/
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Received on Fri May 23 07:08:38 2014

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