Arwen Global (Python package "arwen_global", distribution "gpuwm-global")
Copyright 2026 ArWen contributors

Licensed under the Apache License, Version 2.0. This distribution is an
independent implementation. The upstream works, datasets and services it
derives from, reads, or is verified against retain their own licences and
notices, and the ones that place an obligation on a derivative are recorded
below.

This file travels with every copy of this distribution, in the source
distribution and inside the wheel, under Apache-2.0 section 4(c).

Where a licence requires its text to be reproduced rather than merely
named, it is reproduced. The short notices are in the sections below; the
full texts are in the licenses/ directory, which ships in the source
distribution and, through pyproject.toml's license-files declaration, in
the wheel at gpuwm_global-<version>.dist-info/licenses/licenses/ (PEP 639
keeps each file's source path, hence the doubled component). Every section
below names the file that carries its text.

Notices also sit beside the code they belong to, which is what several of
these licences ask for and what a reader looking at one file rather than at
the whole distribution finds first. arwen_global/core/rrtmgp.py and
arwen_global/core/npref.py open with the notice for what they transcribe.
The CUDA sources cannot: their bytes are the source_sha256 a run receipt
records, and a comment in one would move that digest without moving a
compiled image, so their notice is
arwen_global/core/kernels/LICENSE-third-party.txt, in the same directory.
The four WRF parameter tables ship with
arwen_global/data/noah_tables/LICENSE-WRF.txt beside them.

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Relationship to the gpuwm engine

Arwen Global runs on the gpuwm engine, which it depends on rather than
vendors: the GRIB2 source engine, the observation front doors, the
static-field builder, the NetCDF bridge, the LETKF filter core, the wrfout
writer and the product renderer are all gpuwm's, and gpuwm carries its own
NOTICE covering them. Reading this file is therefore not a substitute for
reading gpuwm's; both are installed together and both apply.

The physics is the exception, and it is carried rather than depended on.
The scheme modules this model was graded with, their CUDA device sources
and the Noah parameter tables travel inside this distribution, as
arwen_global.core and arwen_global/data/noah_tables, cut from the source
revision SOURCE.md names. They carry the same Apache-2.0 terms they carry
there, and the third-party notices below cover the references they are
written from.

Two modules that were part of the engine's source tree moved here when this
package was carved out of it, because each had exactly one consumer and that
consumer is this model: the global physics registry (now
arwen_global.physics.registry) and the rows-grid helper (now
arwen_global.statics_rows). They carry the same Apache-2.0 terms they carried
there.

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WRF / NCAR / UCAR

This software is not affiliated with, endorsed by, or sponsored by the
National Center for Atmospheric Research (NCAR) or the University Corporation
for Atmospheric Research (UCAR). The Weather Research and Forecasting (WRF)
model, developed at NCAR, is the reference for the physics parameterizations
this model runs through its native adapters, and "WRF", "WPS" and "wrfout"
are used nominatively to name that reference and the file format it defined.

The parameterization schemes named in this model's configuration surface,
the Noah land-surface model, the YSU planetary boundary layer, Morrison
microphysics, Grell-Freitas and New Tiedtke convection, RRTMG and RTE+RRTMGP
radiation, are published schemes with their own authors and their own
notices. This distribution carries its own transcriptions of those schemes
in arwen_global.core, written from the published descriptions and the
reference sources rather than copied from them, and it carries four WRF
parameter tables verbatim from WRF's run/ directory: LANDUSE.TBL,
VEGPARM.TBL, SOILPARM.TBL and GENPARM.TBL, in
arwen_global/data/noah_tables, with a provenance note beside them. UCAR
asks that its notice travel with any copy of WRF, so that notice is
reproduced here in full:

  WRF was developed at the National Center for Atmospheric Research (NCAR)
  which is operated by the University Corporation for Atmospheric Research
  (UCAR). NCAR and UCAR make no proprietary claims, either statutory or
  otherwise, to this version and release of WRF and consider WRF to be in
  the public domain for use by any person or entity for any purpose
  without any fee or charge. UCAR requests that any WRF user include this
  notice on any partial or full copies of WRF. WRF is provided on an "AS
  IS" basis and any warranties, either express or implied, including but
  not limited to implied warranties of non-infringement, originality,
  merchantability and fitness for a particular purpose, are disclaimed. In
  no event shall UCAR be liable for any damages, whatsoever, whether
  direct, indirect, consequential or special, that arise out of or in
  connection with the access, use or performance of WRF, including
  infringement actions.

  WRF is a registered trademark of the University Corporation for
  Atmospheric Research (UCAR).

That notice is also reproduced at licenses/LICENSE-WRF-public-domain.txt
and beside the tables at arwen_global/data/noah_tables/LICENSE-WRF.txt.

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RRTMG (Atmospheric and Environmental Research, Inc.)

UCAR's declaration above disclaims UCAR's own claims. It cannot and does
not dispose of anyone else's, and WRF says so itself by preserving foreign
notices inside phys/. One body of code this distribution carries is one of
those, and its filename does not say so: the McICA subcolumn cloud
generator the radiation is driven with is WRF's RRTMG generator, not
rte-rrtmgp's.

arwen_global/core/kernels/rrtmgp_mcica.cu transcribes module
mcica_subcol_gen_sw in WRF v4.6.1 phys/module_ra_rrtmg_sw.F: the kissvec
generator at lines 2008-2040 and the maximum-random overlap walk at
1778-1813, as its own header says. Its host driver in
arwen_global/core/rrtmgp.py and its float64 mirror in
arwen_global/core/npref.py mirror the same routine, and both open with this
notice. Nothing else here transcribes RRTMG: the eight legacy RRTMG
translation units and the RRTMG coefficient files stay with the engine.

RRTMG is the work of Atmospheric and Environmental Research, Inc. (AER),
not of UCAR. WRF's copy carries AER's own notice, seven times in
module_ra_rrtmg_lw.F and nine times in module_ra_rrtmg_sw.F, in three
copyright-year spans:

  Copyright 2002-2008, Atmospheric & Environmental Research, Inc. (AER).
  This software may be used, copied, or redistributed as long as it is
  not sold and this copyright notice is reproduced on each copy made.
  This model is provided as is without any express or implied warranties.
                        (http://www.rtweb.aer.com/)

All three spans are reproduced at
licenses/NOTICE-AER-RRTMG-as-distributed-with-WRF.txt.

This distribution takes the material under AER's own current grant
instead. AER publishes RRTMG_LW and RRTMG_SW at https://github.com/AER-RC
under the BSD 3-Clause licence, "Copyright (c) 2020, Atmospheric and
Environmental Research"; that offer is public, current and unconditional,
and a copyright holder may licence its own work on any terms it chooses.
The BSD-3-Clause text is reproduced in full at
licenses/LICENSE-AER-RRTMG-BSD-3-Clause.txt, which is how its clause 1
(source) and clause 2 (binary) notice conditions are performed.

Version 0.1.0 filed this kernel under the RTE+RRTMGP section below, on the
strength of its name, and shipped neither AER text. That is the error this
section corrects.

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RTE+RRTMGP

The radiation this model runs is a transcription of
earth-system-radiation/rte-rrtmgp. Three carried files hold the
transcription itself: the device kernels
arwen_global/core/kernels/rrtmgp_gas.cu, rrtmgp_cloud.cu and rrtmgp_rte.cu,
each of which cites upstream commit
fa107a16120051c4124305c6b3d4c87059119f58 in its own header
(rrtmgp_gas.cu line 3, rrtmgp_cloud.cu line 3, rrtmgp_rte.cu line 14). The
GPU scheme arwen_global/core/rrtmgp.py drives them and the float64 mirror
in arwen_global/core/npref.py mirrors them, and both open with this notice.

Three more files share the rrtmgp_ prefix and are NOT this work, named
here so the prefix is not read as the scope. rrtmgp_mcica.cu transcribes
WRF's RRTMG McICA generator and is covered by the section above.
rrtmgp_validation.cu is this project's own input validation, written
against the host validators in arwen_global/core/rrtmgp.py rather than
transcribed from anything. rrtmgp_planck_common.cuh is this project's own
in-kernel Planck derivation, pinned bitwise to rrtmgp_gas.cu.

rte-rrtmgp is BSD 3-Clause:

  Copyright (c) 2015-2025, Atmospheric and Environmental Research,
    Regents of the University of Colorado,
    Trustees of Columbia University in the City of New York.
  All rights reserved.

Clause 1 requires a source redistribution to retain that notice, the list
of conditions and the disclaimer. The full text is at
licenses/LICENSE-RTE-RRTMGP-BSD-3-Clause.txt.

The k-distribution DATA is a different work with an earlier copyright
line. It is not in this distribution: it arrives with the engine's
companion data package, which carries its own copy of that licence beside
the files.

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FP32 libm transcriptions -- Arm optimized-routines

The schemes carried here are graded bitwise against a gfortran/glibc
reference, so they call hand transcriptions of the standard
single-precision libm routines rather than CUDA's, whose expf, powf and
tgammaf are measurably different functions. In this distribution those
transcriptions are in one file,
arwen_global/core/kernels/glibc_flt32.cuh, which the kernel loader
prepends to the Grell-Freitas and New Tiedtke translation units.

The logf, expf, exp2f and powf cores, and their data tables, are Arm's
work. They were written by Szabolcs Nagy and published at
https://github.com/ARM-software/optimized-routines (math/logf.c,
math/expf.c, math/exp2f.c, math/powf.c and the corresponding
math/*_data.c) in August 2017, then imported into glibc for 2.27/2.28 by
their own author, and transcribed here from glibc's copy at
sysdeps/ieee754/flt-32/.

The grant elected is Arm's MIT. At the vintage glibc imported (Arm
86067a740541, 2017-08-11, taken into glibc at 4ea49f4c08ee on 2017-09-04)
those files read "Copyright (C) 2017, ARM Limited" under Apache-2.0; Arm
relicensed the same work to MIT fifteen months later, at 11253b0b9d6b on
2018-11-12, and from there each file carries

    Copyright (c) 2017-2018, Arm Limited.
    SPDX-License-Identifier: MIT

A copyright holder may licence its own work on any terms it chooses, and
Arm's MIT offer over this code is public, current, and made by the
retained copyright holder. MIT requires its copyright notice and its
permission notice to travel with every copy; Arm's LICENSE is reproduced
in full at licenses/LICENSE-Arm-optimized-routines-MIT.txt and beside the
code at arwen_global/core/kernels/LICENSE-third-party.txt.

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FP32 libm transcriptions -- FDLIBM (Sun Microsystems, Inc.)

The same header carries expm1f and the positive arm of the lgammaf
reduction, which descend from FDLIBM, developed at SunPro, a Sun
Microsystems, Inc. business, and converted to single precision at Cygnus
Support. glibc carries them substantially unmodified and presents them,
in its own LICENSES file, as Sun's code. The notice below is the whole of
that licence: its single condition is that it be preserved, and this is
that preservation. It is also at licenses/LICENSE-FDLIBM-SunPro.txt and
beside the code at
arwen_global/core/kernels/LICENSE-third-party.txt.

    Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.

    Developed at SunPro, a Sun Microsystems, Inc. business.
    Permission to use, copy, modify, and distribute this
    software is freely granted, provided that this notice
    is preserved.

The two grants above are scoped by routine name on purpose. They cover
the routines named in them and nothing else; no other code in that file
takes anything from Arm or from Sun, and none of it is offered to a
reader on the strength of these two notices.

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The gamma in the device sources

gfk_gamma_product, gfk_gammaf_positive and gfk_tgamma in
arwen_global/core/kernels/glibc_flt32.cuh are this project's own work
under this distribution's Apache-2.0 licence. They are
not a transcription of any C library. Nothing in that block needs a
third-party notice.

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CRTM (Community Radiative Transfer Model)

The satellite radiance legs of this model are verified against the Community
Radiative Transfer Model, developed by the Joint Center for Satellite Data
Assimilation (JCSDA). CRTM is a reference this model is scored against, not
a component of it: no CRTM source, table or coefficient file is transcribed
or redistributed here. The tools that drive a CRTM installation expect the
reader to obtain it from JCSDA under its own terms.

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Test cases from the published literature

The dry dynamical-core cases this model is verified on are standard published
test problems, implemented from their published descriptions rather than from
anyone's code:

  - the Williamson et al. (1992) shallow-water test suite;
  - the Held and Suarez (1994) idealized forcing.

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Data services (not redistributed)

This software fetches data at the user's request from third-party services
and redistributes none of it. Each service carries its own terms and the user
is subject to them:

  - NOAA: the GDAS and GFS analyses and forecasts, GOES-R ABI Level 1b
    radiances, NDBC marine observations, and the IGRA2 radiosonde archive;
  - NASA and NOAA jointly: ATMS microwave radiances from the JPSS series;
  - ECMWF: the open-data global forecast set, under ECMWF's own open licence;
  - Iowa State University Environmental Mesonet: the surface station archive;
  - the WMO Information System 2 (WIS2) global brokers;
  - UCAR COSMIC: GNSS radio-occultation profiles.

The geography archive this model builds its static surface fields from is
fetched through the engine and is not part of this distribution.

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Rust components (not redistributed in this artefact)

Every data path in this software is Rust, and none of those binaries are
inside this wheel. They are built from the engine's own workspace and
delivered as release assets. Their sources, and the crates they vendor,
carry their own licences in the trees that hold them.
