NCL is 'mostly' successful.
http://www.ncl.ucar.edu/Document/Tools/ncl_filedump.shtml
http://www.ncl.ucar.edu/Document/Tools/ncl_convert2nc.shtml
------------
[1]
I have attached an 'ncl_filedump' of the GRIB file's contents
The .grb file extension is required so the NCL will treat the file
as a grib file.
%> ncl_filedump od_wave_an_20060601_20060630.grb > od_wave_an.overview
NOTE:
NCL will look for a file named "od_wave_an_20060601_20060630.grb"
If it does not find a file with that name, it will look for the file
"od_wave_an_20060601_20060630" and 'remember' to treat it as a GRIB file.
[2]
When I tried to convert the *entire file* to netCDF via
%> ncl_convert od_wave_an_20060601_20060630.grb
NCL returned some messages
"warning:GenericUnPack: NCL does not yet handle gridded data with
complex packing: no valid values returned"
[3]
If you look at the attached "od_wave_an.overview", you can select
a subset of the variables. You mention 'slope' and 'wave height'.
I selected a few variables with these descriptions and was successful
in creating a netCDF file.
%> ncl_convert2nc od_wave_an_20060601_20060630.grb -v
initial_time0_hours, g0_lat_1,
g0_lon_2,initial_time0,AWH_GDS0_MSL_10,MSQS_GDS0_MSL_10
I have placed the resulting file at:
http://www.cgd.ucar.edu/~shea/od_wave_an_20060601_20060630.nc
When you have downloaded the file, let me know so I can delete it.
[4]
Actually, NCL could do what you want rather easily.
[a] Read directly from the GRIB file(s)
[b] Use
http://www.ncl.ucar.edu/Document/Functions/Contributed/linint2_points_Wrap.shtml
to bilinearly interpolate to user specified locations
[c] plot
[d] create netCDF
Of course, the 'rub' is you have to invest time to learn NCL.
Good luck.
D
> Lonneke Goddijn-Murphy wrote:
>
>> Hi, I have a data set concerning waves from ECMWF encoded in GRIB Ed. 1 (FM92-VIII), and want to extract the data. I am used to using MATLAB, but the MATLAB GRiB reader I found can't read ECMWF's parameter table 140. I suspect it would be too slow anyway. I have never used NCL, and I don't know anyone who has, and I would like to find out if I can get GRiB data out reasonably straightforward. The data is gridded, 0.25 resolution (the area is 10 x 7 degrees), and 4 times daily (period is one month). There are 30 parameters. What I want to achieve is: get the values of certain parameters (eg wave height, slope etc.) at 170 times and locations (stations during a cruise). Can I do this using NCL? I know how to read NetCDF in MATLAB. I would do it station for station if I had to.
>>
>> I don't expect an answer explaining how to do it, just an indication if NCL is the way to go or not.
>>
>>
Copyright (C) 1995-2009 - All Rights Reserved
University Corporation for Atmospheric Research
NCAR Command Language Version 5.1.1
The use of this software is governed by a License Agreement.
See http://www.ncl.ucar.edu/ for more details.
Variable: f (file variable)
filename: od_wave_an_20060601_20060630
path: od_wave_an_20060601_20060630
file global attributes:
dimensions:
initial_time0_hours = 120
g0_lat_1 = 41
g0_lon_2 = 29
variables:
float WMB_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Model bathymetry
units : m
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 219
forecast_time : 0
forecast_time_units : hours
float MP1_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period based on first moment
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 220
forecast_time : 0
forecast_time_units : hours
float MP2_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period based on second moment
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 221
forecast_time : 0
forecast_time_units : hours
float WDW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Wave spectral directional width
units : -
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 222
forecast_time : 0
forecast_time_units : hours
float P1WW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period based on first moment for wind waves
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 223
forecast_time : 0
forecast_time_units : hours
float P2WW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period based on second moment for wind waves
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 224
forecast_time : 0
forecast_time_units : hours
float DWWW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Wave spectral directional width for wind waves
units : -
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 225
forecast_time : 0
forecast_time_units : hours
float P1PS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period based on first moment for swell
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 226
forecast_time : 0
forecast_time_units : hours
float P2PS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period based on second moment for swell
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 227
forecast_time : 0
forecast_time_units : hours
float DWPS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Wave spectral directional width for swell
units : -
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 228
forecast_time : 0
forecast_time_units : hours
float SWH_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Significant wave height
units : m
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 229
forecast_time : 0
forecast_time_units : hours
float MWD_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave direction
units : degrees
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 230
forecast_time : 0
forecast_time_units : hours
float PP1D_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Peak period of 1D spectra
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 231
forecast_time : 0
forecast_time_units : hours
float MWP_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean wave period
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 232
forecast_time : 0
forecast_time_units : hours
float CDWW_GDS0_HTGL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Coefficient of drag with waves
units : -
_FillValue : 1e+20
level_indicator : 105
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 233
level : 10
forecast_time : 0
forecast_time_units : hours
float SHWW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Significant height of wind waves
units : m
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 234
forecast_time : 0
forecast_time_units : hours
float MDWW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean direction of wind waves
units : degrees
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 235
forecast_time : 0
forecast_time_units : hours
float MPWW_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean period of wind waves
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 236
forecast_time : 0
forecast_time_units : hours
float SHTS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Significant height of total swell
units : m
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 237
forecast_time : 0
forecast_time_units : hours
float MDTS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean direction of total swell
units : degrees
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 238
forecast_time : 0
forecast_time_units : hours
float MPTS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean period of total swell
units : s
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 239
forecast_time : 0
forecast_time_units : hours
float MSQS_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Mean square slope of waves
units : dimensionless
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 244
forecast_time : 0
forecast_time_units : hours
float WIND_GDS0_HTGL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : 10 metre wind speed
units : m s**-1
_FillValue : 1e+20
level_indicator : 105
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 245
level : 10
forecast_time : 0
forecast_time_units : hours
float AWH_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Altimeter wave height
units : m
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 246
forecast_time : 0
forecast_time_units : hours
float ACWH_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Altimeter corrected wave height
units : m
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 247
forecast_time : 0
forecast_time_units : hours
float ARRC_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Altimeter range relative correction
units : -
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 248
forecast_time : 0
forecast_time_units : hours
float 2DFD_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : 2D wave spectra (single)
units : m**2 s radian**-1
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 251
forecast_time : 0
forecast_time_units : hours
float WSK_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Wave spectral kurtosis
units : -
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 252
forecast_time : 0
forecast_time_units : hours
float BFI_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Benjamin-Feir index
units : -
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 253
forecast_time : 0
forecast_time_units : hours
float WSP_GDS0_MSL_10 ( initial_time0_hours, g0_lat_1, g0_lon_2 )
center : European Center for Medium-Range Weather Forecasts (RSMC)
long_name : Wave spectral peakedness
units : s**-1
_FillValue : 1e+20
level_indicator : 102
gds_grid_type : 0
parameter_table_version : 140
parameter_number : 254
forecast_time : 0
forecast_time_units : hours
double initial_time0_hours ( initial_time0_hours )
long_name : initial time
units : hours since 1800-01-01 00:00
double initial_time0_encoded ( initial_time0_hours )
long_name : initial time encoded as double
units : yyyymmddhh.hh_frac
float g0_lat_1 ( g0_lat_1 )
long_name : latitude
GridType : Cylindrical Equidistant Projection Grid
units : degrees_north
Dj : 0.25
Di : 0.25
Lo2 : 352
La2 : 50
Lo1 : 345
La1 : 60
float g0_lon_2 ( g0_lon_2 )
long_name : longitude
GridType : Cylindrical Equidistant Projection Grid
units : degrees_east
Dj : 0.25
Di : 0.25
Lo2 : 352
La2 : 50
Lo1 : 345
La1 : 60
string initial_time0 ( initial_time0_hours )
long_name : Initial time of first record
units : mm/dd/yyyy (hh:mm)
_______________________________________________
ncl-talk mailing list
List instructions, subscriber options, unsubscribe:
http://mailman.ucar.edu/mailman/listinfo/ncl-talk
Received on Wed Jun 24 2009 - 10:01:35 MDT
This archive was generated by hypermail 2.2.0 : Wed Jul 01 2009 - 06:11:45 MDT