<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div>I am using NCL 6.5.0. I have no problem reading the grib file.</div><div><br></div><div><b>%> ncl<br> <br> NCAR Command Language Version 6.5.0 <br></b></div><div><br></div><div>ncl 0> f = addfile("e20c_an_temp_r360x180_ml_199410.<b>grib</b>","r")<br>ncl 1> print(f)<br>ncl 2> t = f->TMP_P0_L105_GLL0 <br>printVarSummary(t)</div><div>ncl 3> printVarSummary(t)<br><br>Variable: t<br>Type: float<br>Total Size: 2941061760 bytes<br> 735265440 values<br>Number of Dimensions: 4<br>Dimensions and sizes: [initial_time0_hours | 124] x [lv_HYBL0 | 91] x [lat_0 | 181] x [lon_0 | 360]<br>Coordinates: <br> initial_time0_hours: [1707120..1707858]<br> lv_HYBL0: [ 1..91]<br> lat_0: [90..-90]<br> lon_0: [ 0..359]<br>Number Of Attributes: 11<br> center : European Center for Medium-Range Weather Forecasts<br> production_status : Operational products<br> long_name : Temperature<br> units : K<br> _FillValue : 1e+20<br> grid_type : Latitude/longitude<br> parameter_discipline_and_category : Meteorological products, Temperature<br> parameter_template_discipline_category_number : ( 0, 0, 0, 0 )<br> level_type : Hybrid level<br> forecast_time : 0<br> forecast_time_units : hours</div><div><br></div><div>ncl 4> printMinMax(t,0)<br></div><div>(0) Temperature (K) : min=170.211 max=313.993<br></div></div></div></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Mar 12, 2019 at 5:30 AM De Vries Andries <<a href="mailto:andries.devries@env.ethz.ch">andries.devries@env.ethz.ch</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">Dear NCL Team & Users,<br>
<br>
I have an issue with reading in ERA-20C grib files from ECMWF that contain data on model levels. No matter if it is data on a regular (1x1 degree grid) or a gaussian grid (N80), I can not read the variables within the file, see for example the first print statements below.<br>
<br>
When I convert the grib file to netcdf format, using the tool cdo {cdo -f nc copy {infile} {outfile}}, there is no problem; I can read in the netcdf file and variables without any problem, see the second print statement below. Ideally, however, I would like to use NCL to read in the grib files without converting them first to netcdf format. Any idea how to achieve this?<br>
<br>
Two side comments (1) I can read in ERA-20C grib files with data on pressure levels, surface, or isentropic levels without any problem problem; there is no need to convert them to netcdf format, and (2) Also, I can read in ERA-Interim grib files with data on model levels without any problems that are downloaded in the same manner & format as the ERA-20C data.<br>
<br>
@NCL TEAM; I copied an example ERA-20C file in grib and netcdf format with temperature on model levels for the year 199410 to <a href="http://ftp.cgd.ucar.edu" rel="noreferrer" target="_blank">ftp.cgd.ucar.edu</a> <br>
<br>
Kind regards,<br>
Andries<br>
<br>
-----------------------------------------------------------------------------------------------------------------------------------------------------------------<br>
READING IN ERA-20C GRIB FILE WITH DATA ON MODEL LEVELS; CANNOT READ VARIABLES<br>
-----------------------------------------------------------------------------------------------------------------------------------------------------------------<br>
<br>
Copyright (C) 1995-2015 - All Rights Reserved<br>
University Corporation for Atmospheric Research<br>
NCAR Command Language Version 6.3.0<br>
The use of this software is governed by a License Agreement.<br>
See <a href="http://www.ncl.ucar.edu/" rel="noreferrer" target="_blank">http://www.ncl.ucar.edu/</a> for more details.<br>
ncl 0> a=addfile("e20c_an_temp_r360x180_ml_199410.grib","r")<br>
<br>
ncl 1> print(a)<br>
<br>
print(a)<br>
<br>
Variable: a<br>
Type: file<br>
filename: (null)<br>
path: e20c_an_temp_r360x180_ml_199410.grib<br>
file global attributes:<br>
dimensions:<br>
variables:<br>
<br>
-----------------------------------------------------------------------------------------------------------------------------------------------------------------<br>
READING IN ERA-20C NETCDF FILE WITH DATA ON MODEL LEVELS; READS VARIABLES<br>
-----------------------------------------------------------------------------------------------------------------------------------------------------------------<br>
<br>
Copyright (C) 1995-2015 - All Rights Reserved<br>
University Corporation for Atmospheric Research<br>
NCAR Command Language Version 6.3.0<br>
The use of this software is governed by a License Agreement.<br>
See <a href="http://www.ncl.ucar.edu/" rel="noreferrer" target="_blank">http://www.ncl.ucar.edu/</a> for more details.<br>
<br>
ncl 0> a=addfile("<a href="http://e20c_an_temp_r360x180_ml_199410.nc" rel="noreferrer" target="_blank">e20c_an_temp_r360x180_ml_199410.nc</a>","r")<br>
<br>
ncl 1> print(a) <br>
<br>
Variable: a<br>
Type: file<br>
filename: e20c_an_temp_r360x180_ml_199410<br>
path: <a href="http://e20c_an_temp_r360x180_ml_199410.nc" rel="noreferrer" target="_blank">e20c_an_temp_r360x180_ml_199410.nc</a><br>
file global attributes:<br>
CDI : Climate Data Interface version 1.9.5 (<a href="http://mpimet.mpg.de/cdi" rel="noreferrer" target="_blank">http://mpimet.mpg.de/cdi</a>)<br>
Conventions : CF-1.6<br>
history : Thu Feb 14 11:02:46 2019: cdo -f nc copy /atmosdyn/devriesa/DATA/ERA20C/e20c_an_temp_r360x180_ml_199410.grib /atmosdyn/devriesa/DATA/ERA20C-MOD/NC/<a href="http://e20c_an_temp_r360x180_ml_199410.nc" rel="noreferrer" target="_blank">e20c_an_temp_r360x180_ml_199410.nc</a><br>
institution : European Centre for Medium-Range Weather Forecasts<br>
CDO : Climate Data Operators version 1.9.5 (<a href="http://mpimet.mpg.de/cdo" rel="noreferrer" target="_blank">http://mpimet.mpg.de/cdo</a>)<br>
dimensions:<br>
time = 124 // unlimited<br>
lon = 360<br>
lat = 181<br>
lev = 91<br>
nhyi = 92<br>
nhym = 91<br>
variables:<br>
double time ( time )<br>
standard_name : time<br>
units : hours since 1994-10-1 00:00:00<br>
calendar : proleptic_gregorian<br>
axis : T<br>
<br>
double lon ( lon )<br>
standard_name : longitude<br>
long_name : longitude<br>
units : degrees_east<br>
axis : X<br>
<br>
double lat ( lat )<br>
standard_name : latitude<br>
long_name : latitude<br>
units : degrees_north<br>
axis : Y<br>
<br>
double lev ( lev )<br>
standard_name : hybrid_sigma_pressure<br>
long_name : hybrid level at layer midpoints<br>
formula : hyam hybm (mlev=hyam+hybm*aps)<br>
formula_terms : ap: hyam b: hybm ps: aps<br>
units : level<br>
positive : down<br>
<br>
double hyai ( nhyi )<br>
long_name : hybrid A coefficient at layer interfaces<br>
units : Pa<br>
<br>
double hybi ( nhyi )<br>
long_name : hybrid B coefficient at layer interfaces<br>
units : 1<br>
<br>
double hyam ( nhym )<br>
long_name : hybrid A coefficient at layer midpoints<br>
units : Pa<br>
<br>
double hybm ( nhym )<br>
long_name : hybrid B coefficient at layer midpoints<br>
units : 1<br>
<br>
float t ( time, lev, lat, lon )<br>
standard_name : air_temperature<br>
long_name : Temperature<br>
units : K<br>
param : 0.0.0<br>
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</blockquote></div>