I am currently trying to utilize the meteocean-api in Python to download and use NORA3 data. This uses the nco package in the background to work with the files. I downloaded it, and all of its dependencies (including nco), simply using:

conda install -c conda-forge metocean-api

This caused a lot of headaches on my computer, including the need to reinclude the sqlite3 DLL back in the correct location, but eventually everything started to work again. Now I am trying to get a simple block of data to start analyzing, but I keep running into an error:

*** nco.nco.NCOException: (returncode:3221225781) b''

From what I understand from a lot of googling, this exact returncode might mean that I am missing DLL’s? But again, I don’t really know how to figure out which are missing, or if this is even the real issue.

Below you can see a reproduction of my code (deeply simplified and with numbers changed):

from metocean_api import ts

latitude = 50
longitude = 6
start_string = "2023-01-01 00:00:00+0000"
end_string = "2023-01-02 00:00:00+0000"
type = "wind_sub"

df_ts = ts.TimeSeries(lon=longitude, lat=latitude,
                      start_time=start_string, end_time=end_string,
                      product= f'NORA3_{type}')
    
df_ts.import_data(save_csv=True)

Note that I am using a Windows 11 machine and Python 3. I know neither of these packages were built for Windows use, but I want to try to make this work.

I dove deep into the problem and it is stemming from nco itself. The error occurs here:

nco.ncks(input=infile , output=tempfile, options=opt)

where infile = https://thredds.met.no/thredds/dodsC/nora3_subset_atmos/wind_hourly/arome3kmwind_1hr_202301.nc

tempfile = cacheNORA3_wind_sub_lon6.00000lat50.00000_20230501.nc

and opt = ['-O -v wind_speed, wind_direction, longitude, latitude -d x,3082360.8 -d y,-367476.97']

Eventually the code gets to here, within the nco call function:

proc = subprocess.Popen(
                cmd,
                stdin=subprocess.DEVNULL,
                stderr=subprocess.PIPE,
                stdout=subprocess.PIPE,
                env=environment,
            )

Where the cmd is:

[‘C:Usersmy_file_path_to_the_python_3_environmentLibrarybinncks’,
‘-O’, ‘-v’, ‘wind_speed,wind_direction,longitude,latitude’, ‘-d’,
‘x,3082360.8’, ‘-d’, ‘y,-367476.97’,
‘–output=cacheNORA3_wind_sub_lon6.00000lat50.00000_20230501.nc’,
‘https://thredds.met.no/thredds/dodsC/nora3_subset_atmos/wind_hourly/arome3kmwind_1hr_202301.nc’]

Again, I am very new to ALL of this (not a computer scientist or trained programmer myself), and just want to see if I can make this work, so we can include NORA3 data. Does anyone know how to fix this error? And how can I troubleshoot these sorts of ambiguous errors in the future myself as well?