Scheduled Downtime
On Friday 21 April 2023 @ 5pm MT, this website will be down for maintenance and expected to return online the morning of 24 April 2023 at the latest

Inconsistent XLAND and ISLTYP

This post was from a previous version of the WRF&MPAS-A Support Forum. New replies have been disabled and if you have follow up questions related to this post, then please start a new thread from the forum home page.

lkugler

New member
Hi,

During the cold air outbreak in January, we had a crash in RUC LSM due to ISLTYP/XLAND being at inconsistent values (one indicating LAND, the other WATER).

According to ncks, the ISLTYP in the wrfinput_d01 file is 3 and xland=1, which is fine.
In SURFACE_DRIVER() we had xland=1 (land) and ISLTYP=14 (water) such that in LSMRUC() the subroutine SFCTMP() is called, which should never be called for ISLTYP=14. Finally there is a division by zero in SOILPROP(), such that the heat capacity becomes NaN.

To see where this comes from, we printed XLAND and ISLTYP for this gridpoint after reading wrfinput_d01 and wrfbdy_d01:

After reading wrfinput:
Code:
   wrf main: calling open_r_dataset for wrfinput
 after reading wrfinput
 xland(144,701), grid%isltyp(144,701)  0.0000000E+00           0

After reading wrfbdy_d01:
Code:
 d01 2019-01-19_12:00:00 in med_latbound_in preparing to read
 d01 2019-01-19_12:00:00  Opening: wrfbdy_d01
 after reading wrfbdy_d01
 xland(144,701), grid%isltyp(144,701)   1.000000              14

I assume that after reading wrfinput, the xland and isltyp are not already written to these variables.
After reading wrfbdy the variables are inconsistent.

Questions:
  • Is it possible that the error is related to reading the wrfbdy file?
  • Is it possible that it is an issue with indexing, i.e. MPI / OpenMP reading the wrong (i,j)? Or that the grid is shifted?
  • How can we solve this? An additional IF to find inconsistencies in xland/isltyp at initialization time?
Best regards,
Lukas
 
It seems that the issue is related to a shifted grid / wrong indices, as all the inconsistent gridpoints (land-points with xland=1) are one gridpoint to the north-east of a water gridpoint that is changed to sea-ice (due to the cold air outbreak), but it is still not clear why and what one can do to avoid that.
 
We will take a look at this issue probably after Feb. 19. This is because we are on a business trip the following two weeks. Thanks for your patience.
Please keep us updated if there is more information related to this.
 
Top