NEMSpy

NEMSpy generates configuration files (nems.configure, config.rc, model_configure, atm_namelist.rc) for coupled modeling applications run with a compiled NEMS binary (not included).

pip install nemspy

NEMS implements the National Unified Operational Prediction Capability (NUOPC), and configuration files built for NEMS will also work for most NUOPC applications.

Documentation can be found at https://nemspy.readthedocs.io

organization / responsibility

NEMSpy is developed by the Coastal Marine Modeling Branch (CMMB) of the Office of Coast Survey (OCS), a part of the National Oceanic and Atmospheric Administration (NOAA), an agency of the United States federal government.

• Zachary Burnett (lead) - zachary.burnett@noaa.gov
• Saeed Moghimi - saeed.moghimi@noaa.gov
• Jaime Calzada (past)

usage

from datetime import datetime, timedelta
from pathlib import Path

from nemspy import ModelingSystem
from nemspy.model import ADCIRCEntry, AtmosphericForcingEntry, WaveWatch3ForcingEntry

# directory to which configuration files should be written
output_directory = Path(__file__).parent / 'nems_configuration'

# directory containing forcings
forcings_directory = Path(__file__).parent / 'forcings'

# model run time
start_time = datetime(2020, 6, 1)
duration = timedelta(days=1)
end_time = start_time + duration

# returning interval of main run sequence
interval = timedelta(hours=1)

# model entries
ocean_model = ADCIRCEntry(processors=11, Verbosity='max', DumpFields=False)
atmospheric_mesh = AtmosphericForcingEntry(
    filename=forcings_directory / 'wind_atm_fin_ch_time_vec.nc', processors=1
)
wave_mesh = WaveWatch3ForcingEntry(
    filename=forcings_directory / 'ww3.Constant.20151214_sxy_ike_date.nc', processors=1
)

# instantiate model system with model entries
nems = ModelingSystem(
    start_time=start_time,
    end_time=end_time,
    interval=interval,
    ocn=ocean_model,
    atm=atmospheric_mesh,
    wav=wave_mesh,
)

# form connections between models
nems.connect('ATM', 'OCN')
nems.connect('WAV', 'OCN')

# define execution order
nems.sequence = [
    'ATM -> OCN',
    'WAV -> OCN',
    'ATM',
    'WAV',
    'OCN',
]

# write configuration files to the given directory
nems.write(directory=output_directory, overwrite=True, include_version=True)

output

nems.configure

# `nems.configure` generated with NEMSpy 1.0.0
# EARTH #
EARTH_component_list: ATM WAV OCN
EARTH_attributes::
  Verbosity = off
::

# ATM #
ATM_model:                      atmesh
ATM_petlist_bounds:             0 0
ATM_attributes::
  Verbosity = off
::

# WAV #
WAV_model:                      ww3data
WAV_petlist_bounds:             1 1
WAV_attributes::
  Verbosity = off
::

# OCN #
OCN_model:                      adcirc
OCN_petlist_bounds:             2 12
OCN_attributes::
  Verbosity = max
  DumpFields = false
::

# Run Sequence #
runSeq::
  @3600
    ATM -> OCN   :remapMethod=redist
    WAV -> OCN   :remapMethod=redist
    ATM
    WAV
    OCN
  @
::

model_configure

# `model_configure` generated with NEMSpy 1.0.0
total_member:            1
print_esmf:              .true.
namelist:                atm_namelist.rc
PE_MEMBER01:             13
start_year:              2020
start_month:             6
start_day:               1
start_hour:              0
start_minute:            0
start_second:            0
nhours_fcst:             24
RUN_CONTINUE:            .false.
ENS_SPS:                 .false.

config.rc

# `config.rc` generated with NEMSpy 1.0.0
 atm_dir: ~/forcings
 atm_nam: wind_atm_fin_ch_time_vec.nc
 wav_dir: ~/forcings
 wav_nam: ww3.Constant.20151214_sxy_ike_date.nc

related projects

• NOAA-EMC/NEMS
• esmf-org/esmf
• noaa-ocs-modeling/ADC-WW3-NWM-NEMS