pycontrails.models.cocip.CocipFlightParams¶
- class pycontrails.models.cocip.CocipFlightParams(copy_source=True, interpolation_method='linear', interpolation_bounds_error=False, interpolation_fill_value=nan, interpolation_localize=False, interpolation_use_indices=False, interpolation_q_method=None, verify_met=True, downselect_met=True, met_longitude_buffer=(10.0, 10.0), met_latitude_buffer=(10.0, 10.0), met_level_buffer=(40.0, 40.0), met_time_buffer=(np.timedelta64(0, 'h'), np.timedelta64(0, 'h')), process_emissions=True, dt_integration=np.timedelta64(30, 'm'), dz_m=200.0, effective_vertical_resolution=2000.0, smooth_true_airspeed=True, smooth_true_airspeed_window_length=7, smooth_true_airspeed_polyorder=1, humidity_scaling=None, preprocess_lowmem=False, compute_tau_cirrus_in_model_init='auto', filter_sac=True, filter_initially_persistent=True, persistent_buffer=None, verbose_outputs=False, compute_atr20=False, global_rf_to_atr20_factor=0.0151, initial_wake_vortex_depth=0.5, sedimentation_impact_factor=0.5, default_nvpm_ei_n=1000000000000000.0, wind_shear_enhancement_exponent=0.5, nvpm_ei_n_enhancement_factor=1.0, min_ice_particle_number_nvpm_ei_n=10000000000000.0, max_depth=1500.0, unterstrasser_ice_survival_fraction=False, radiative_heating_effects=False, contrail_contrail_overlapping=False, dz_overlap_m=500.0, radius_threshold_um=<factory>, habits=<factory>, habit_distributions=<factory>, rf_sw_enhancement_factor=1.0, rf_lw_enhancement_factor=1.0, min_altitude_m=6000.0, max_altitude_m=13000.0, max_seg_length_m=40000.0, max_age=np.timedelta64(20, 'h'), min_tau=1e-06, max_tau=10000000000.0, min_n_ice_per_m3=1000.0, max_n_ice_per_m3=1e+20, aircraft_performance=None)¶
Bases:
CocipParams
Flight specific CoCiP parameters.
- __init__(copy_source=True, interpolation_method='linear', interpolation_bounds_error=False, interpolation_fill_value=nan, interpolation_localize=False, interpolation_use_indices=False, interpolation_q_method=None, verify_met=True, downselect_met=True, met_longitude_buffer=(10.0, 10.0), met_latitude_buffer=(10.0, 10.0), met_level_buffer=(40.0, 40.0), met_time_buffer=(np.timedelta64(0, 'h'), np.timedelta64(0, 'h')), process_emissions=True, dt_integration=np.timedelta64(30, 'm'), dz_m=200.0, effective_vertical_resolution=2000.0, smooth_true_airspeed=True, smooth_true_airspeed_window_length=7, smooth_true_airspeed_polyorder=1, humidity_scaling=None, preprocess_lowmem=False, compute_tau_cirrus_in_model_init='auto', filter_sac=True, filter_initially_persistent=True, persistent_buffer=None, verbose_outputs=False, compute_atr20=False, global_rf_to_atr20_factor=0.0151, initial_wake_vortex_depth=0.5, sedimentation_impact_factor=0.5, default_nvpm_ei_n=1000000000000000.0, wind_shear_enhancement_exponent=0.5, nvpm_ei_n_enhancement_factor=1.0, min_ice_particle_number_nvpm_ei_n=10000000000000.0, max_depth=1500.0, unterstrasser_ice_survival_fraction=False, radiative_heating_effects=False, contrail_contrail_overlapping=False, dz_overlap_m=500.0, radius_threshold_um=<factory>, habits=<factory>, habit_distributions=<factory>, rf_sw_enhancement_factor=1.0, rf_lw_enhancement_factor=1.0, min_altitude_m=6000.0, max_altitude_m=13000.0, max_seg_length_m=40000.0, max_age=np.timedelta64(20, 'h'), min_tau=1e-06, max_tau=10000000000.0, min_n_ice_per_m3=1000.0, max_n_ice_per_m3=1e+20, aircraft_performance=None)¶
Methods
Attributes
Aircraft performance model
Add additional metric of ATR20 and global yearly mean RF to model output.
Compute
"tau_cirrus"
variable in pressure-level met data during model initialization.Experimental.
Copy input
source
data on evalDefault
nvpm_ei_n
value if no data provided and emissions calculations fails.Downselect input
MetDataset`
to region aroundsource
.Apply Euler's method with a fixed step size of
dt_integration
.Difference in altitude between top and bottom layer for stratification calculations, [\(m\)].
Experimental.
Vertical resolution (m) associated to met data.
Filter out waypoints if they don't satisfy the initial persistent criteria Passing in a non-default value is unusual, but is included to allow for false negative calibration and model uncertainty studies.
Filter out waypoints if the don't satisfy the SAC criteria Note that the SAC algorithm will still be run to calculate
T_critical_sac
for use estimating initial ice particle number.Constant factor used to convert global- and year-mean RF, [\(W m^{-2}\)], to ATR20, [\(K\)], given by [Yin et al., 2023].
Humidity scaling
Initial wake vortex depth scaling factor.
If True, points lying outside interpolation will raise an error
Used for outside interpolation value if
interpolation_bounds_error
is FalseExperimental.
Interpolation method.
Experimental.
Experimental.
Max age of contrail evolution.
Maximum altitude domain in simulation, [\(m\)] If set to
None
, this check is disabled.Upper bound for contrail plume depth, constraining it to realistic values.
Maximum contrail ice particle number per volume of air to prevent unrealistic values.
Maximum contrail segment length in simulation to prevent unrealistic values, [\(m\)].
Maximum contrail optical depth to prevent unrealistic values.
Met latitude buffer [WGS84] for Cocip evolution.
Met level buffer [\(hPa\)] for Cocip initialization and evolution.
Met longitude [WGS84] buffer for Cocip evolution.
Met time buffer for input to
Flight.downselect_met()
Only applies whendownselect_met
is True.Minimum altitude domain in simulation, [\(m\)] If set to
None
, this check is disabled.Lower bound for
nvpm_ei_n
to account for ambient aerosol particles for newer engines, [\(kg^{-1}\)]Minimum contrail ice particle number per volume of air.
Minimum contrail optical depth.
Multiply flight black carbon number by enhancement factor.
Continue evolving contrail waypoints
persistent_buffer
beyond end of contrail life.Experimental.
Determines whether
Cocip.process_emissions()
runs on modelCocip.eval()
Set toFalse
when input Flight includes emissions data.Experimental.
Scale longwave radiative forcing.
Scale shortwave radiative forcing.
Sedimentation impact factor.
Smoothing parameters for true airspeed.
Experimental.
Add additional values to the flight and contrail that are not explicitly necessary for calculation.
Call
_verify_met()
on model instantiation.Parameter denoted by \(n\) in eq.
Radius threshold for regime bins, [\(\mu m\)] This is the row index label for
habit_distributions
.Particle habit (shape) types.
Mix of ice particle habits in each radius regime.
- aircraft_performance = None¶
Aircraft performance model
- as_dict()¶
Convert object to dictionary.
We use this method instead of dataclasses.asdict to use a shallow/unrecursive copy. This will return values as Any instead of dict.
- Returns:
dict[str
,Any]
– Dictionary version of self.
- compute_atr20 = False¶
Add additional metric of ATR20 and global yearly mean RF to model output. These are not standard CoCiP outputs but based on the derivation used in the first supplement to [Yin et al., 2023]. ATR20 is defined as the average temperature response over a 20 year horizon.
- compute_tau_cirrus_in_model_init = 'auto'¶
Compute
"tau_cirrus"
variable in pressure-level met data during model initialization. Must be one of"auto"
,True
, orFalse
. If set to"auto"
,"tau_cirrus"
will be computed during model initialization iff the met data is dask-backed. Otherwise, it will be computed during model evaluation after the met data is downselected.
- contrail_contrail_overlapping = False¶
Experimental. Radiative effects due to contrail-contrail overlapping Account for change in local contrail shortwave and longwave radiative forcing due to contrail-contrail overlapping.
Added in version 0.45.
- copy_source = True¶
Copy input
source
data on eval
- default_nvpm_ei_n = 1000000000000000.0¶
Default
nvpm_ei_n
value if no data provided and emissions calculations fails.
- downselect_met = True¶
Downselect input
MetDataset`
to region aroundsource
.
- dt_integration = np.timedelta64(30,'m')¶
Apply Euler’s method with a fixed step size of
dt_integration
. Advected waypoints are interpolated against met data once eachdt_integration
.
- dz_m = 200.0¶
Difference in altitude between top and bottom layer for stratification calculations, [\(m\)]. Used to approximate derivative of “lagrangian_tendency_of_air_pressure” layer.
- dz_overlap_m = 500.0¶
Experimental. Contrail-contrail overlapping altitude interval If
contrail_contrail_overlapping
is set to True, contrails will be grouped into altitude intervals, and all contrails within each altitude interval are treated as one contrail layer where they do not overlap.
- effective_vertical_resolution = 2000.0¶
Vertical resolution (m) associated to met data. Constant below applies to ECMWF data.
- filter_initially_persistent = True¶
Filter out waypoints if they don’t satisfy the initial persistent criteria Passing in a non-default value is unusual, but is included to allow for false negative calibration and model uncertainty studies.
- filter_sac = True¶
Filter out waypoints if the don’t satisfy the SAC criteria Note that the SAC algorithm will still be run to calculate
T_critical_sac
for use estimating initial ice particle number. Passing in a non-default value is unusual, but is included to allow for false negative calibration and model uncertainty studies.
- global_rf_to_atr20_factor = 0.0151¶
Constant factor used to convert global- and year-mean RF, [\(W m^{-2}\)], to ATR20, [\(K\)], given by [Yin et al., 2023].
- habit_distributions¶
Mix of ice particle habits in each radius regime. Rows indexes are
radius_threshold_um
elements. Columns indexes arehabits
particle habit type. See Table 2 from [Schumann et al., 2011].
- habits¶
Particle habit (shape) types. This is the column index label for
habit_distributions
. See Table 2 in [Schumann et al., 2011].
- humidity_scaling = None¶
Humidity scaling
- initial_wake_vortex_depth = 0.5¶
Initial wake vortex depth scaling factor. This factor scales max contrail downward displacement after the wake vortex phase to set the initial contrail depth. Denoted \(C_{D0}\) in eq (14) in [Schumann, 2012].
- interpolation_bounds_error = False¶
If True, points lying outside interpolation will raise an error
- interpolation_fill_value = nan¶
Used for outside interpolation value if
interpolation_bounds_error
is False
- interpolation_localize = False¶
Experimental. See
pycontrails.core.interpolation
.
- interpolation_method = 'linear'¶
Interpolation method. Supported methods include “linear”, “nearest”, “slinear”, “cubic”, and “quintic”. See
scipy.interpolate.RegularGridInterpolator
for the description of each method. Not all methods are supported by all met grids. For example, the “cubic” method requires at least 4 points per dimension.
- interpolation_q_method = None¶
Experimental. Alternative interpolation method to account for specific humidity lapse rate bias. Must be one of
None
,"cubic-spline"
, or"log-q-log-p"
. IfNone
, no special interpolation is used for specific humidity. The"cubic-spline"
method applies a custom stretching of the met interpolation table to account for the specific humidity lapse rate bias. The"log-q-log-p"
method interpolates in the log of specific humidity and pressure, then converts back to specific humidity. Only used by models calling tointerpolate_met()
.
- interpolation_use_indices = False¶
Experimental. See
pycontrails.core.interpolation
.
- max_age = np.timedelta64(20,'h')¶
Max age of contrail evolution.
- max_altitude_m = 13000.0¶
Maximum altitude domain in simulation, [\(m\)] If set to
None
, this check is disabled.
- max_depth = 1500.0¶
Upper bound for contrail plume depth, constraining it to realistic values. CoCiP only uses the ambient conditions at the mid-point of the Gaussian plume, and the edges could be in subsaturated conditions and sublimate. Important when
radiative_heating_effects
is enabled.
- max_n_ice_per_m3 = 1e+20¶
Maximum contrail ice particle number per volume of air to prevent unrealistic values.
- max_seg_length_m = 40000.0¶
Maximum contrail segment length in simulation to prevent unrealistic values, [\(m\)].
- max_tau = 10000000000.0¶
Maximum contrail optical depth to prevent unrealistic values.
- met_latitude_buffer = (10.0, 10.0)¶
Met latitude buffer [WGS84] for Cocip evolution.
- met_level_buffer = (40.0, 40.0)¶
Met level buffer [\(hPa\)] for Cocip initialization and evolution.
- met_longitude_buffer = (10.0, 10.0)¶
Met longitude [WGS84] buffer for Cocip evolution.
- met_time_buffer = (np.timedelta64(0,'h'), np.timedelta64(0,'h'))¶
Met time buffer for input to
Flight.downselect_met()
Only applies whendownselect_met
is True.
- min_altitude_m = 6000.0¶
Minimum altitude domain in simulation, [\(m\)] If set to
None
, this check is disabled.
- min_ice_particle_number_nvpm_ei_n = 10000000000000.0¶
Lower bound for
nvpm_ei_n
to account for ambient aerosol particles for newer engines, [\(kg^{-1}\)]
- min_n_ice_per_m3 = 1000.0¶
Minimum contrail ice particle number per volume of air.
- min_tau = 1e-06¶
Minimum contrail optical depth.
- nvpm_ei_n_enhancement_factor = 1.0¶
Multiply flight black carbon number by enhancement factor. A value of 1.0 provides no scaling. Primarily used to support uncertainty estimation.
- persistent_buffer = None¶
Continue evolving contrail waypoints
persistent_buffer
beyond end of contrail life. Passing in a non-default value is unusual, but is included to allow for false negative calibration and model uncertainty studies.
- preprocess_lowmem = False¶
Experimental. If
True
, attempt to reduce memory consumption during aircraft performance and initial contrail formation/persistent calculations by callingMetDataArray.interpolate()
withlowmem=True
.IMPORTANT:
Memory optimizations used when
proprocess_lowmem=True
are designed for meteorology backed by dask arrays with a chunk size of 1 along the time dimension. This option may degrade performance if dask if not used or if chunks contain more than a single time step.The impact on runtime of setting
preprocess_lowmem=True
depends on how meteorology data is chunked. Runtime is likely to increase if meteorology data is chunked in time only, but may decrease if meteorology data is also chunked in longitude, latitude, and level.Changes to data access patterns with
preprocess_lowmem=True
alter locations where interpolation is in- vs out-of-bounds. As a consequence, Cocip output withpreprocess_lowmem=True
is only guaranteed to match output withpreprocess_lowmem=False
when run withinterpolation_bounds_error=True
to ensure no out-of-bounds interpolation occurs.
- process_emissions = True¶
Determines whether
Cocip.process_emissions()
runs on modelCocip.eval()
Set toFalse
when input Flight includes emissions data.
- radiative_heating_effects = False¶
Experimental. Radiative heating effects on contrail cirrus properties. Terrestrial and solar radiances warm the contrail ice particles and cause convective turbulence. This effect is expected to enhance vertical mixing and reduce the lifetime of contrail cirrus. This parameter is experimental, and the CoCiP implementation of this parameter may change.
Added in version 0.28.9.
- radius_threshold_um¶
Radius threshold for regime bins, [\(\mu m\)] This is the row index label for
habit_distributions
. See Table 2 in [Schumann et al., 2011].
- rf_lw_enhancement_factor = 1.0¶
Scale longwave radiative forcing. Primarily used to support uncertainty estimation.
- rf_sw_enhancement_factor = 1.0¶
Scale shortwave radiative forcing. Primarily used to support uncertainty estimation.
- sedimentation_impact_factor = 0.5¶
Sedimentation impact factor. Denoted by \(f_{T}\) in eq. (35) of [Schumann, 2012]. Schumann describes this as “an important adjustable parameter”, and sets it to 0.1 in the original publication. In [Schumann and Graf, 2013], a value of 0.5 is referenced after comparing CoCiP predictions to observations.
- smooth_true_airspeed = True¶
Smoothing parameters for true airspeed. Only used for Flight models. Passed directly to
scipy.signal.savgol_filter()
. Seepycontrails.Flight.segment_true_airspeed()
for details.
- smooth_true_airspeed_polyorder = 1¶
- smooth_true_airspeed_window_length = 7¶
- unterstrasser_ice_survival_fraction = False¶
Experimental. Improved ice crystal number survival fraction in the wake vortex phase. Implement [Unterstrasser, 2016], who developed a parametric model that estimates the survival fraction of the contrail ice crystal number after the wake vortex phase based on the results from large eddy simulations. This replicates Fig. 4 of [Kärcher, 2018].
Added in version 0.50.1.
- verbose_outputs = False¶
Add additional values to the flight and contrail that are not explicitly necessary for calculation. See also
CocipGridParams.verbose_outputs_formation
andCocipGridParams.verbose_outputs_evolution
.
- verify_met = True¶
Call
_verify_met()
on model instantiation.
- wind_shear_enhancement_exponent = 0.5¶
Parameter denoted by \(n\) in eq. (39) of [Schumann, 2012].