PollyNET / Pollynet_Processing_Chain

NRT lidar data processing program for multiwavelength polarization Raman lidar network (PollyNET)
https://polly.tropos.de/
GNU General Public License v3.0
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Add reader for cloudnet ecmwf profile data #205

Closed martin-rdz closed 1 year ago

martin-rdz commented 1 year ago

The cloudnet datacenter provides profile extracts from ECMWF IFS for stations on the extraction list (https://cloudnetpy.readthedocs.io/en/latest/quickstart.html#model-data). A daily netcdf file contains hourly profiles with 136 height levels (https://cloudnetpy.readthedocs.io/en/latest/fileformat.html#model-file). This data should be superior to the GDAS files.

The datasource can be either configured in the config files or in matlab directly (hinting to https://github.com/PollyNET/picasso-nb-interface ;) )

PollyConfig.meteorDataSource = 'nc_cloudnet';
PicassoConfig.gdas1_folder = '/oceanethome/model/ecmwf/profiles/ecmwf/';

Example for arielle at Neumayer: grafik

Open issue: The relative humidity is provided above water and ice depending on temperature. I am not sure what the effect is on downstream data analysis. Quoting from the ncdump

        float rh(time, level) ;
                rh:_FillValue = -999.9f ;
                rh:long_name = "Relative humidity" ;
                rh:units = "1" ;
                rh:missing_value = -999.9f ;
                rh:comment = "With respect to liquid above 0 degrees C and with respect to ice below 0 degrees C. 
                                         Calculated using Goff-Gratch formula." ;
                rh:standard_name = "relative_humidity" ;

However, also the specific humidity is available in the file, so we could calculate on our own.