NetCDF files no longer open using Scientific DataSet library

Software and Tools Other - Software and tools
1

Hello all,
I’m hoping that someone can help me out. We have a software that downloads ERA5 files in netCDF format. We have been using the Scientific DataSet library in C# (namespace Microsoft.Research.Science.Data.Imperative) to open netCDF files and extract the data which has been working great.

Since the CDS-Beta is upcoming, I followed the steps and updated my credential file and upgraded netCDF. I also had to change ‘format’ to ‘data_format’ in the request JSON. I was able to successfully download netCDF files however the software that opens and extracts the .nc files is now throwing an error ‘NetCDF4 Error’ and I can’t figure out why.

Are the netCDF files downloaded thru CDS-Beta different from those downloaded from the current CDS?

Thanks for your support!

2

Hi Liz,
CDS-Beta uses a new grib to netcdf converter; this page describes some of the differences (including the move to netCDF4):

Hope that helps
Kevin

3

Hi Kevin,
Thank you for your reply. It seems that we’re not the only ones experiencing some challenges with the new converter.

I think the error that I am running into may be related to the netCDF error: Attempt to use a feature that was not turned on when netCDF was built.

When I do a ‘ncdump -k’ with a .nc file downloaded from the old API, it returns with ‘64-bit offset’. When I do the same command with one of the newer netCDFs, it returns with ‘Attempt to use a feature that was not turned on when netCDF was built.’

When I do a ncdump with a file from the old API, it successfully opens and displays the contents of the file. When I do the same ncdump with a new file, it returns with the same error.

I truly hope that this can get resolved!!
Liz

4

Hi Liz,
I think the issue is with the software you are using; it looks like the version of ‘ncdump’ you are using was not built with netCDF4 support turned on, so it cannot read the new netCDF(4) files from CDS-Beta. Can you re-install ‘ncdump’ (from NCO tools) with netCDF4 support enabled?
Thanks,
Kevin

5

Hi Kevin,
Thank you again for your support. I have netCDF4.9.2-NC4-64.exe installed on my Windows machine which is supposed to have support for netCDF4. I tried installing again to see if there is a checkbox to turn on netCDF4 support but I didn’t see anything like that.