Hello!

Been running into extensive sigma2p interpolation errors and am looking for some help finding a reliable solution. I am running many different configuration tests of RegCM, and then interpolating to pressure as the vertical coordinate using sigma2p. I can't seem to find a reliable methodology to follow for sigma2p implementation, as it seems like whether sigma2p errors out is completely random, and the fix is not the same for all configurations.

Whether this error occurs seems to not just depend on the configuration, but also how many levels I am interpolating to. I've written about 2 examples and what debugging processes work or what don't work to get sigma2p running. The below examples also represent two different configurations of RegCM:

Example 1: sigma2p works perfectly fine if set for 11 plevs, but bumping to 12 plevs (based on the formatting suggested by regcm documentation), sigma2p does not work. Subselecting to have less data using nco operator "ncks" does not fix the problem.
Example 2: sigma2p errors for 12 plevs. I've tried subselecting the data using "ncks" and that has resolved the problem for this example. I can even run at higher plevs like 15-20 plevs.

Of course, there are also configurations where running sigma2p just works the first time around and doesn't error out.

This is the error I receive:

`Program received signal SIGSEGV: Segmentation fault - invalid memory reference.

Backtrace for this error:
#0 0x7fa8c141e62f in ???
#1 0x440f39 in ???
#2 0x403974 in ???
#3 0x7fa8c1e3eed5 in GOMP_parallel
at ../.././libgomp/parallel.c:178
#4 0x40bdbe in ???
#5 0x403388 in ???
#6 0x7fa8c140a864 in ???
#7 0x4033bd in ???
#8 0xffffffffffffffff in ???
Segmentation fault (core dumped)`

The forum will not let me attach the example netcdf files or namelist files I would like to, but if anyone would like those I am happy to share over email.

Thanks for the input!