options.yaml

# SPDX-FileCopyrightText: 2021 Wolfgang Traylor <wolfgang.traylor@senckenberg.de>
#
# SPDX-License-Identifier: CC0-1.0

###############################################################################
###############################################################################
# USER SETTINGS
#
# User-defined settings for preparing TraCE-21ka paleoclimate data for
# LPJ-GUESS
#

directories:
  # Paths, either absolute or relative to the root of the Git repository.
  # ("~" for home directory and environment variables are allowed.)
  # Directory for temporary files.
  heap: "./heap"
  # Directory for final output files.
  output: "./output"

# Geographic extent of study area.
region:
  # Longitude: 0° to 360° E
  lon: [130, 230]
  # Latitude: -90° to +90° N
  lat: [50, 80]

# The time range of interest in years BP. Possible values range from 22000 BP
# to -40 BP (i.e. 1990 CE).
time_range: [100, -40]

# Whether to concatenate results into one big, monolithic file per variable.
# If set to 'yes', there will be smaller output files with 100 years each, but
# LPJ-GUESS cannot natively read multiple files.
# Valid options: 'yes' or 'no'
concatenate: 'no'

###############################################################################
###############################################################################
# HARD-CODED SETTINGS.
#
# Don’t change this unless you know what you are doing.
#

# Interpolation algorithm for regridding (downscaling) the NetCDF files.
# See here for detailed descriptions:
# http://www.earthsystemmodeling.org/esmf_releases/public/ESMF_6_3_0rp1/ESMF_refdoc/node3.html#SECTION03020000000000000000
regrid_algorithm: 'bilinear'

# Variables in the CRU NetCDF files as they correspond to the TraCE-21ka
# variables. The CRU files are also named like their variables.
# Note that FSDS needs to be treated separately.
cru_vars:
  CLDTOT: 'cld'
  PRECT: 'pre'
  TREFHT: 'tmp'

# For calculating wet days: The minimum amount of rain to count a day as “wet”.
precip_threshold: 0.1  # [mm/day]

# This file provides the reference grid resolution for downscaling TraCE files.
# It is an arbitrarily chosen original CRU file.
regrid_template_file: 'cru_ts4.01.1921.1930.pre.dat.nc'

# NetCDF attributes as they shall appear in the output files.
nc_attributes:
  # TODO: cloud cover
  # Note that the "time" dimension attributes are set in
  # `trace_for_guess/convert_time_unit.py`.
  lat:
    long_name: 'latitude'
    standard_name: 'latitude'
    units: 'degrees_north'
  lon:
    long_name: 'longitude'
    standard_name: 'longitude'
    units: 'degrees_east'
  PRECT:
    long_name: 'Total (convective and large-scale) precipitation rate (liq + ice)'
    standard_name: 'precipitation_flux'
    units: 'kg m-2 s-1'
  FSDS:
    long_name: 'Mean daily surface incident shortwave radiation'
    standard_name: 'surface_downwelling_shortwave_flux'
    units: 'W m-2'
  TREFHT:
    long_name: 'Near surface air temperature at 2m'
    standard_name: 'air_temperature'
    units: 'K'
  wet_days:
    long_name: 'wet_days'
    standard_name: 'number_of_days_with_lwe_thickness_of_precipitation_amount_above_threshold'
    units: 'count'

# The deflation level (0 bis 9) for the `ncks` command.
# From the NCO manual 4.7.8-alpha02:
# > Minimal deflation (dfl_lvl = 1) achieves considerable storage compression
# > with little time penalty. Higher deflation levels require more time for
# > compression. File sizes resulting from minimal (dfl_lvl = 1) and maximal
# > (dfl_lvl = 9) deflation levels typically differ by less than 10% in size.
compression_level: 1

# Chunk sizes (number of elements) for each dimension.
# See the NCO reference for more details:
# http://nco.sourceforge.net/nco.html#Chunking
chunks:
  lon: 1
  lat: 1
  time: 1200  # = 100 years
  # Cache for NCO chunking operation in Bytes.
  cache: 1000000000  # = 1 GB