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Convert NetCDF meteo. data from COSMO-EU reanalysis (lon/lat) into projected UTM32 coordinate system
Added by Aissa Sehili about 1 year ago
Hi all,
I'm trying to convert meteorological data from a netdcf cosmo-eu NetCDF file (u,v,p,t) with 0.0625 degree lon/lat resolution into a projected UTM32 coordinate system around the German Bight.
What would be the best method here?
Many thanks.
Cheers
Aissa
Hi Aissa,
can you upload one time step of the COSMO-EU data?
Hi Karin,
thanks for the reply. Please find attached the first step of the data.
Cheers,
Aissa
Do you have an UTM32 example file too?
Hi Katrin,
the (converted) UTM32 meteo file is an ascii one, where the data are defined over an equidistant square grid.
In practice, the eastward wind file would look like (just as an example):
- BEGIN HEADER
NODATA_value = 999.00
n_cols = 273
n_rows = 273
grid_unit = m
x_llcenter = -320001 x lower left corner
y_llcenter = 5.37514e+06 y lower left corner
dx = 4300.
dy = 4300.
n_quantity = 1
quantity1 = x_wind
unit1 = m s-1
- END OF HEADER
TIME = 0 hours since 2010-01-01 01:00:00 +00:00
data over X and Y
TIME = 1 hours since 2010-01-01 01:00:00 +00:00
data ....
This is done via a matlab code using a method called geo2utm.m (available online), but it doesn't seem to work correctly for my purposes.
For that reason, I'm looking for original projection methods from the CDO library.
Cheers,
Aissa
I get a result that looks ok but I'm not sure and don't give any guarantee!
gridtype = projection
gridsize = 77361
xsize = 241
ysize = 321
xname = x
xunits = "m"
yname = y
yunits = "m"
xfirst = -100000
xinc = 4300
yfirst = 5375140
yinc = 4300
grid_mapping = UTM32
grid_mapping_name = utm32
proj_params = "+proj=utm +zone=32 +north +datum=WGS84 +ellps=GRS80 +lat_0=0 +lon_0=9 +k_0=0.9996 +x_0=500000 +y_0=0 +units=m"
cdo -remapnn,gridfile_UTM32.txt cosmo-eu_GB_1st_step.nc outfile.nc
Original data:
Remap to UTM32:
Hi Karin,
that worked perfectly. Many thanks again for your support.
Cheers,
Aissa