ecRad - Modular atmospheric radiation scheme, (C) Copyright 2014-
ECMWF.  This software is licensed under the terms of the Apache
Licence Version 2.0 which can be obtained at
http://www.apache.org/licenses/LICENSE-2.0.  In applying this licence,
ECMWF does not waive the privileges and immunities granted to it by
virtue of its status as an intergovernmental organisation nor does it
submit to any jurisdiction.

The ifsrrtm directory of this package includes a modified version of
the gas optics part of the Rapid Radiative Transfer Model for GCMS
(RRTMG).  RRTMG was developed at Atmospheric & Environmental Research
(AER), Inc., Lexington, Massachusetts and is available under the
"3-clause BSD" license; for details, see ifsrrtm/AER-BSD3-LICENSE.

bin/drhook_merge_walltime.pl is from Eckhard Tschirschnitz, Cray,
2006.

For the use in ICON, the following changes have been made to the original ecRad code:
- OpenACC port for the use of ecRad on GPU architectures
- Code optimizations to improve performance on vector architectures
- Replace yomhook with ecradhook to avoid linking conflicts with other ECMWF software used by ICON