Opened 8 months ago

Closed 7 months ago

#2663 closed help (fixed)

NDdiag issues: orography not of the right size + input fields required

Reported by: ambrogio Owned by: um_support
Component: NDdiag Keywords:
Cc: Platform: Other
UM Version:


Dear Willie,

as per our conversation, I'm having some problems in running NDdiag on UM global model operational data. In detail, the error message I get is:

Input file: /group_workspaces/jasmin2/incompass/users/ambrogio/NDdiag_files/global/20161207_input_NDdiag_fields_all.pp

Diagnostics File: /home/users/ambrogio/programs/NDdiag_2.2.3/nddiag.control.lagranto
Output File: /group_workspaces/jasmin2/incompass/users/ambrogio/NDdiag_files/global/NDdiag4Lagranto/20161207NDdiag_lagranto.pp
Orography File: /group_workspaces/jasmin2/incompass/users/ambrogio/NDdiag_files/global/orography_global.pp

Date: 2018/11/01 Time: 10:31

Input grid ……

N(theta), N(rho) : 70 71
(NX,NY) p-grid : 1536 1153
(NUX,NUY) v-grid : 1536 1152

Output grid (NX,NY) : 1536 1153
DATE : 2016/12/ 7 16: 0
Orography file /group_workspaces/jasmin2/incompass/users/ambrogio/NDdiag_files/global/orography_global.pp does not contain an orography of the right size.
Please specify an orography.

I've copied the input and the orography file in Archer, you can find them here: /work/n02/n02/ambrogio/wmcginty_ticket_nov2018/.
The only post-processing I've done on these fields, after selecting them from the operational pp files downloaded from the Met Office archive, has been to change their endianness so they can be read by NDdiag.

As an aside, the NDdiag user guide says that the only input fields necessary for the program to run are:
Surface pressure
Orographic height
rate of change of pressure (omega)
specific humidity
My experience instead is that Pressure on rho and on theta levels have to be included too otherwise I'll get the error: "STOP Can't determine the number of RHO-levels". (or THETA-levels). Also, if I include w instead of omega NDdiag usually runs fine, so I wonder if the user guide needs to be changed or if there is anything odd with the version I donwloaded from the CMS website.

Apologies for the long email and thanks for the attention!

Best wishes

Change History (3)

comment:1 Changed 8 months ago by willie

Hi Ambrogio,

Oh, dear. The V component of wind is 1536x1153. Everything else is 1536x1152. I'm afraid you'll need to regenerate the file.


comment:2 Changed 8 months ago by willie

Hi Ambrogio,

This seems to be the difference between n768 and n768e (e is for ENDGAME). The ancillaries for n768 are on 1536x1153 whilst the n768e are on 1536x1152.


Last edited 8 months ago by willie (previous) (diff)

comment:3 Changed 7 months ago by willie

  • Component changed from UM Tools to NDdiag
  • Platform set to Other
  • Resolution set to fixed
  • Status changed from new to closed
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