How to calculate trend from multiple nc files？
Added by Wilma Wang 29 days ago
Hi, I have 100-year monthly SST data, which are stored in 100 nc files for each year, how to calculate trend from these nc files using nco or cdo？
It seems like I should merge these 100 files into one, but each file are at least 1~2 GB, which is too large to be merged.
Does anybody know this? Plese help me, thanks.
Replies (4)
RE: How to calculate trend from multiple nc files？ - Added by Uwe Schulzweida 27 days ago
Combine the trend with the mergetime operator:
cdo trend -merge infiles outfile1 outfile2
RE: How to calculate trend from multiple nc files？ - Added by Wilma Wang 21 days ago
thank you so much for the prompt reply (and solution)!
When I do:
cdo trend -merge *.nc outfile1.nc outfile2.nc
I got：
cdo trend (Abort): Too many streams! Operator needs 1 input and 2 output streams.
And the cdo version is 1.8.2
How can I fix it? Plese help me, thanks.
RE: How to calculate trend from multiple nc files？ - Added by Uwe Schulzweida 20 days ago
In CDO version 1.8.2 single quotation marks are required for the filenames and the correct function is mergetime:
cdo trend -mergetime '*.nc' outfile1.nc outfile2.nc
RE: How to calculate trend from multiple nc files？ - Added by Wilma Wang 20 days ago
It works perfectly. I really appreciate your solution.