[netcdfgroup] netCDF Operators NCO version 4.9.1 are woke

• To: NCO Announce Mail List <nco-announce@xxxxxxxxxxxxxxxxxxxxx>, netcdfgroup@xxxxxxxxxxxxxxxx
• Subject: [netcdfgroup] netCDF Operators NCO version 4.9.1 are woke
• From: Charlie Zender <zender@xxxxxxx>
• Date: Thu, 19 Dec 2019 15:55:45 -0800

The netCDF Operators NCO version 4.9.1 are woke.

http://nco.sf.net (Homepage, Mailing lists, Help)
http://github.com/nco (Source Code, Issues, Releases, Developers)

What's new?

Version 4.9.1 contains an important bugfix for vertical interpolation,
and two small new features for ncclimo and ncpdq. It also fixes some
autoconf-build issues that affected some users with Intel compilers,
and those attempting parallel builds of NCO.

Work on NCO 4.9.2 has commenced and will improve NCO weight-generator
accuracy, reduce vertical interpolation memory use, and supply more
accurate weight generation options for rectangular lat-lon grids.

Work on NCO 5.0.0 has commenced "under the hood". A key leap in that
release will be support for netCDF4 user-defined types. Printing of
netCDF4 user-defined types ENUM and VLEN is ready now (though
unsupported) with the --udt flag. 5.0.0 will contain the finished
version of that, and include options for invoking mbtempest in place
of tempest.

Enjoy,
Charlie

NEW FEATURES (full details always in ChangeLog):

A. ncremap changes the default regridder algorithm from ESMF
   "bilinear" to NCO "nco_con", a first-order conservative algorithm
   (similar to ESMF "conserve") that requires no external
   dependencies. Because the default algorithm comes with NCO, users
   without access to ESMF and/or TempestRemap can perform a full
   regridding workflow. Of course many/most users will still wish to
   employ ESMF or TR, and their algorithms are easily accessed:
   ncremap -a nco -s grd_src.nc -d grd_dst.nc -m map.nc   # New default
   ncremap -a bilin -s grd_src.nc -d grd_dst.nc -m map.nc # Old default
   ncremap -a fv2fv -s grd_src.nc -d grd_dst.nc -m map.nc # Tempest
   http://nco.sf.net/nco.html#alg_typ
   http://nco.sf.net/nco.html#ncremap

B. ncclimo can now output spatial-average timeseries.
   The new --glb_avg (or --global_average) option causes ncclimo to
   perform a spatial mean over the timeseries constructed from the
   input data. The main limitation is that it only works for
   timeseries whose horizontal spatial dimension is "ncol" and
   whose area weight is named "area", as in CAM SE/EAM.
   Let us know if this function would be useful to you for other
   models and we can easily add options to make these hardwired values
   specifiable from the command-line.
   ls *mdl*.nc | ncclimo --glb_avg -s 1979 -e 1981 --drc_out=drc_out
   http://nco.sf.net/nco.html#ncclimo
   http://nco.sf.net/nco.html#glb_avg

C. ncpdq has a new map, flt_dbl, to convert single-precision to
   double-precision floating point variables. The resulting variables
   are not packed. All single-precision variables, including
   coordinates, are promoted. Some software requires geospatial data
   in double precision, and this feature simplifies the dataset
   conversion.
   ncpdq -M flt_dbl in.nc out.nc
   ncpdq -M sgl_dbl in.nc out.nc
   http://nco.sf.net/nco.html#flt_dbl
   http://nco.sf.net/nco.html#ncpdq

BUG FIXES:

A. Fix a difficulty that caused Intel compilers to fail to build NCO.
   Now the netcdf.h header, and thus the EXTERNL token, are always
   included and defined during autoconf header checks.
   Thanks to Matthew Thompson of NASA for reporting the issue, and to
   Dave Allured of NOAA for providing the fix.

B. Print WARNING instead of dying when requested to copy the
   _NCProperties attribute. That attribute should not but can be
   exposed through the netCDF API in some circumstances, and this new
   treatment prevents that leakage from breaking workflows. Thanks to
   Rotislav for reporting and Dave Allured for helpful discussions.
   This is really a feature yet listed as a bug-fix because it is
   an incomprehensible technical workaround, the kind of thing users
   should never need to know about.

C. Fix an error when interpolating to/from a pure pressure grid.
   The minimum pressure was not always being initialized, which caused
   (highly) erroneous values when the interpolation type was mss_val.
   This bug only affects NCO installations built by compilers that do
   not automatically initialize allocated memory to preset values.
   Affected output datasets would be obviously corrupted, so nothing
   subtle about this bug. There is no workaround, the only fix is to
   upgrade. Thanks to Sterling Baldwin for reporting this.

D. Fix misuse of autoconf library references. This foiled parallel
   builds, and caused difficulty compiling ncap2. Thanks to Daniel
   Macks for identifying and solving the issue.

Full release statement at http://nco.sf.net/ANNOUNCE
--
Charlie Zender, Earth System Sci. & Computer Sci.
University of California, Irvine 949-891-2429 )'(