gp2sp output
Added by Julia S. over 4 years ago
Hey everyone,
I'm a student, new to cdo, and I was having a question regarding the gp2sp operator.
I have data of geopotential height. I want to spectrally truncate my data to T42, and also remove the large scale background (setting the wavenumbers 0-7 to zero).
Here's what I have done so far:
cdo -b F32 sp2sp,42 -gp2sp -remapbil,n360 ERA5_300hPa_geop_06hourly_1979-2018.nc ERA5_T42_SH_geop_300hPa.nc
For the output file (ERA_T42_SH_geop_300hPa.nc) I get the following dimensions:
dimensions:
time = UNLIMITED ; // (58440 currently)
nc2 = 2 ;
nsp = 946 ;
Can someone tell me what exactly nc2 and nsp are? I have plotted them for one timestep, for nc2=0 and nc2=1 separately (see file attached)
Thanks in advance, Julia
| Figure_1.png (36.9 KB) Figure_1.png |
Replies (3)
RE: gp2sp output - Added by Uwe Schulzweida over 4 years ago
Hi Julia,
nsp means number of spectral coefficients and nc2 contains the real and imaginary part of the complex numbers.
Cheers,
Uwe
RE: gp2sp output - Added by Julia S. over 4 years ago
Uwe Schulzweida wrote:
Hi Julia,
nsp means number of spectral coefficients and nc2 contains the real and imaginary part of the complex numbers.
Cheers,
Uwe
Ahh I see, thanks a lot!
RE: gp2sp output - Added by Susmit Satpathy over 1 year ago
Hello!
I am using the cdo gp2sp operator to convert my data into the spectral space (T119) and would like to know how are the spectral coefficients are arranged.
I would also like to know how can I segregate my data into different scales as:
Large scale (0-4)
Synoptic scale (5-9)
Small scale (10 onwards)
Thanks
Susmit