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increase the levels of the intermediate file of ungrib (modify press_pa)

M

Mary-joe Medlej

New member
Hello,

Is there any possibility to interpolate the intermediate file of ungrib to have more level in the first Km above the ground ?
For example instead of having by default : press_pa = 201300, 200100, 100000, 95000, 90000, 85000, 80000, 75000, 70000, 65000, 60000, 55000, 50000, 45000, 40000, 35000, 30000, 25000, 20000, 15000, 10000, 5000, 1000
I wanna have : press_pa = 201300, 200100, 100000, 95000, 93000, 91000, 89000, 87000, 85000, 83000, 80000, 75000, 70000, 65000, 60000, 55000, 50000, 45000, 40000, 35000, 30000, 25000, 20000, 15000, 10000, 5000, 1000
In fact, I wanna do this, cause I have data on those different levels (93000, 91000, 89000, 87000, 85000, 83000, 80000), and I wanna integrate them to wrf using obsgrid.

Thank you in advance !
 
Unfortunately WRF/WPS doesn't have the capability to interpolate data to different pressure levels. WPS processes data as is, and the utility "mod_levs.exe" can only remove levels.
 
Thank you so much for your reply !
In fact, I've read that the obsgrid process significantly coarsens the vertical resolution of sounding data to the resolution of the initial meteorological data set from GFS.

So, is there any other way to improve my initial conditions by adding in addition to the GFS data, high vertical resolution data from radio-sounding ?
 
GFS analysis products have incorporated as many as possible oberserations, including the sounding data. Basically I don't think it is necessary to conduct assimilation repeatedly.
 
Hello
I would like to know if this problem solved and how to.
I am trying to add one sounding data at a specific location to ERA5 reanalysis. Since I am investigating the planetary boundary layer, I need higher vertical resolution. Thus, I would be really appreciate if someone can provide some guidance or materials. Thank you.
 
f930139 said:
Hello
I would like to know if this problem solved and how to.
I am trying to add one sounding data at a specific location to ERA5 reanalysis. Since I am investigating the planetary boundary layer, I need higher vertical resolution. Thus, I would be really appreciate if someone can provide some guidance or materials. Thank you.
Click to expand...
Hello,

You can use data with higher vertical resolution like the ERA5 model levels
 
@Mary-joe,
Would you please clarify how you process high-resolution model-level ECMWF data? Specifically,
(1) where did you download the data?
(2) which Vtable did you use to ungrib the data?
(3) Any extra options in namelist.wps are required to ungrib the data?
Thank you !
 
Ming Chen said:
@Mary-joe,
Would you please clarify how you process high-resolution model-level ECMWF data? Specifically,
(1) where did you download the data?
(2) which Vtable did you use to ungrib the data?
(3) Any extra options in namelist.wps are required to ungrib the data?
Thank you !
Click to expand...
Hello,

To run WRF using ERA5 model levels I've proceeded this way :

1) I've downloaded the data from the official site. I've downloaded two types of data; surface (Copernicus Climate Data Store | Copernicus Climate Data Store) and levels (Copernicus Climate Data Store | Copernicus Climate Data Store).
I download my data through a python script by following the details on the ECMWF website of how to install the API(How to use the CDS API | Copernicus Climate Data Store). The python script you can find in the page when you click 'download data' then 'show API request'.
For the surface data the required variables that I used :
'10m_u_component_of_wind', '10m_v_component_of_wind', '2m_dewpoint_temperature',
'2m_temperature', 'geopotential', 'land_sea_mask',
'leaf_area_index_high_vegetation', 'mean_sea_level_pressure', 'sea_ice_cover',
'sea_surface_temperature', 'snow_depth', 'soil_temperature_level_1',
'soil_temperature_level_2', 'soil_temperature_level_3', 'soil_temperature_level_4',
'soil_type', 'surface_latent_heat_flux', 'surface_pressure',
'top_net_solar_radiation_clear_sky', 'total_precipitation', 'volumetric_soil_water_layer_1',
'volumetric_soil_water_layer_2', 'volumetric_soil_water_layer_3', 'volumetric_soil_water_layer_4',
'skin_temperature'
For the levels variable : 129/130/131/132/133

For the levels data : use the cdo sp2gp command to convert ERA5 spectral data in GRIB format to Gaussian coordinates in GRIB format.
(Ex: cdo sp2gp input_file.grib output_file.grib)

Then separate each hour in a different file.

2) I used two Vtables. For the model variable I used this one : WRF_Vtable_ECMWF_GRIB2
For the surface level (I used the one attached ERA5_ml)
Then I run ungrib twice by changing the prefix twice in the namelist
&ungrib
prefix = 'SFILE',
--> for surface data
&ungrib
prefix = 'LFILE,
--> for level data

Then before running metgrid:
Calculate PRESSURE from model level data:
a) check that the file ecmwf_coeffs (with the number of levels of ERA5 (137)) is in the same folder as namelist.wps
b) In &metgrid section of namelist.wps add:
fg_name = 'SFILE', 'LFILE',
c) run ./calc_ecmw_p.exe
(PRES files should be created)

3) before running metgrid add in &metgrid section of namelist.wps:
fg_name = 'SFILE', 'LFILE','PRES'

Then run ./metgrid.exe

Then run real.exe and wrf.exe normally
 

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f930139 said:
Hello
I would like to know if this problem solved and how to.
I am trying to add one sounding data at a specific location to ERA5 reanalysis. Since I am investigating the planetary boundary layer, I need higher vertical resolution. Thus, I would be really appreciate if someone can provide some guidance or materials. Thank you.
Click to expand...
However, I did not yet succeeded by running obsgrid on the high-resolution model-level ECMWF
 
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