v0.47.1

Fixes

• Fix bug in PSGrid in which the met data was assumed to be already loaded into memory. This caused errors when running PSGrid with a MetDataset source.
• Fix bug (#86) in which Cocip.eval loses the source fuel type. Instead of instantiating a new Flight or Fleet instance with the default fuel type, the Cocip._bundle_results method now overwrites the self.source.data attribute with the bundled predictions.
• Avoid a memory explosion when running Cocip on a large non-dask-backed met parameter. Previously the tau_cirrus computation would be performed in memory over the entire met dataset.
• Replace datetime.utcfromtimestamp (deprecated in python 3.12) with datetime.fromtimestamp.
• Explicitly support python 3.12 in the pyproject.toml build system.

Internals

• Add compute_tau_cirrus_in_model_init parameter to CocipParams. This controls whether to compute the cirrus optical depth in Cocip.__init__ or Cocip.eval. When set to "auto" (the default), the tau_cirrus is computed in Cocip.__init__ if and only if the met parameter is dask-backed.
• Change data requirements for the EmpiricalGrid aircraft performance model.
• Consolidate ERA5.cache_dataset and HRES.cache_dataset onto common ECMWFAPI.cache_dataset method. Previously the child implementations were identical.
• No longer require the pyproj package as a dependency. This is now an optional dependency, and can be installed with pip install pycontrails[pyproj].

v0.47.0

Implement a Poll-Schumann (PSGrid) theoretical aircraft performance model over a grid.

Breaking changes

• Move the pycontrails.models.aircraft_performance module to pycontrails.core.aircraft_performance.
• Rename PSModel -> PSFlight.

Fixes

• Use the instance fuel attribute in the Fleet.to_flight_list method. Previously, the default JetA fuel was always used.
• Ensure the Fleet.fuel attribute is inferred from the underlying sequence of flights in the Fleet.from_seq method.

Features

• Implement the PSGrid model. For a given aircraft type and position, this model computes optimal aircraft performance at cruise conditions. In particular, this model can be used to estimate fuel flow, engine efficiency, and aircraft mass at cruise. In particular, the PSGrid model can now be used in conjunction with CocipGrid to simulate contrail formation over a grid.
• Refactor the Emissions model so that Emissions.eval runs with source: GeoVectorDataset. Previously, the eval method required a Flight instance for the source parameter. This change allows the Emissions model to run more seamlessly as a sub-model of a gridded model (ie, CocipGrid),
• No longer require pycontrails-bada to import or run the CocipGrid model. Instead, the CocipGridParams.aircraft_performance parameter can be set to any AircraftPerformanceGrid instance. This allows the CocipGrid model to run with any aircraft performance model that implements the AircraftPerformanceGrid interface.
• Add experimental EmpiricalAircraftPerformanceGrid model.
• Add convenience GeoVectorDataset.T_isa method to compute the ISA temperature at each point.

Internals

• Add optional climb_descend_at_end parameter to the Flight.resample_and_fill method. If True, the climb or descent will be placed at the end of each segment rather than the start.
• Define AircraftPerformanceGridParams, AircraftPerformanceGrid, and AircraftPerformanceGridData abstract interfaces for gridded aircraft performance models.
• Add set_attr parameter to Models.get_source_param.
• Better handle source, source.attrs, and params customizations in CocipGrid.
• Include additional classes and functions in the pycontrails.models.emissions module.
• Hardcode the paths to the static data files used in the Emissions and PSFlight models. Previously these were configurable by model parameters.
• Add altitude_ft parameter to the GeoVectorDataset constructor. Warn if at least two of altitude_ft, altitude, and level are provided.
• Allow instantiation of Model instances with params: ModelParams. Previously, the params parameter was required to be a dict. The current implementation checks that the params parameter is either a dict or has type default_params on the Model class.

v0.46.0

Support "dry advection" simulation.

Features

• Add new DryAdvection model to simulate sediment-free advection of an aircraft's exhaust plume. This model is experimental and may change in future releases. By default, the current implementation simulates plume geometry as a cylinder with an elliptical cross section (the same geometry assumed in CoCiP). Wind shear perturbs the ellipse azimuth, width, and depth over the plume evolution. The DryAdvection model may also be used to simulate advection without wind-shear effects by setting the model parameters azimuth, width, and depth to None.
• Add new Dry Advection example notebook highlighting the new DryAdvection model and comparing it to the Cocip model.
• Add optional fill_value parameter to VectorDataset.sum.

Fixes

• (#80) Fix unit error in wake_vortex.turbulent_kinetic_energy_dissipation_rate. This fix affects the estimate of wake vortex max downward displacement and slightly changes Cocip predictions.
• Change the implementation of Flight.resample_and_fill so that lat-lon interpolation is linear in time. Previously, the timestamp associated to a waypoint was floored according to the resampling frequency without updating the position accordingly. This caused errors in segment calculations (e.g., true airspeed).

Internals

• Add optional keep_original_index parameter to the Flight.resample_and_fill method. If True, the time original index is preserved in the output in addition to the new time index obtained by resampling.
• Improve docstrings in wake_vortex module
• Rename wake_vortex functions to remove get_ prefix at the start of each function name.
• Add pytest command line parameter --regenerate-results to regenerate static test fixture results. Automate in make recipe make pytest-regenerate-results.
• Update handling of GeoVectorDataset.required_keys the GeoVectorDataset constructor. Add class variable GeoVectorDataset.vertical_keys for handing the vertical dimension.
• Rename CocipParam.max_contrail_depth -> CocipParam.max_depth.
• Add units.dt_to_seconds function to convert np.timedelta64 to float seconds.
• Rename thermo.p_dz -> thermo.pressure_dz.

v0.45.0

Add experimental support for simulating radiative effects due to contrail-contrail overlap.

Features

• Support simulating contrail contrail overlap when running the Cocip model with a Fleet source. The contrail_contrail_overlapping and dz_overlap_m parameters govern the overlap calculation. This mode of calculation is still experimental and may change in future releases.
• Rewrite the pycontrails.models.cocip.output modules into a single pycontrails.cocip.output_formats module. The new module supports flight waypoint summary statistics, contrail waypoints summary statistics, gridded outputs, and time-slice outputs.
• Add new GeoVectorDataset.to_lon_lat_grid method. This method can be thought of as a partial inverse to the MetDataset.to_vector method. The current implementation is brittle and may be revised in a future release.

Fixes

• Extend Models.set_source_met to allow interpolation_q_method="cubic-spline" when working with MetDataset source (ie, so-called gridded models). Previously a NotImplementedError was raised.
• Ensure the Flight.copy implementation works with Fleet instances as well.
• Avoid looping over keys twice in VectorDataset.broadcast_attrs. This is a slight performance enhancement.
• Fix Fleet signature for compatibility with Flight.
• Fix a few hard-coded assumptions in broadcasting aircraft performance and emissions when running Cocip with a Fleet source. The previous implementation did not consider the possibility of aircraft performance variables on Flight.data and Flight.attrs separately.

Internals

• Add optional raise_error parameter to the VectorDataset.broadcast_attrs method.
• Update Fleet internals.

v0.44.2

Fixes

• Narrow type hints on the ABC AircraftPerformance model. The AircraftPerformance.eval method requires a Flight object for the source parameter.
• In PSModel.eval, explicitly set any aircraft performance data at waypoints with zero true airspeed to np.nan. This avoids numpy RuntimeWarnings without affecting the results.
• Fix corner-case in the polygon.buffer_and_clean function in which the polygon created by buffering the opencv contour is not valid. Now a second attempt to buffer the polygon is made with a smaller buffer distance.
• Ignore RuntimeError raised in scipy.optimize.newton if the maximum number of iterations is reached before convergence. This is a workaround for occasional false positive convergence warnings. The pycontrails use-case may be related to this GitHub issue.
• Update the Models.__init__ warnings when humidity_scaling is not provided. The previous warning provided an outdated code example.
• Ensure the interpolation_q_method used in a parent model is passed into the humidity_scaling child model in the Models.__init__ method. If the two interpolation_q_method values are different, a warning is issued. This could be extended to other model parameters in the future.

Features

• Enable ExponentialBoostLatitudeCorrectionHumidityScaling humidity scaling for the model parameter interpolation_q_method="cubic_spline".
• Add GFS notebook example.

Breaking changes

• Remove ExponentialBoostLatitudeCorrectionHumidityScalingParams. These parameters are now hard-coded in the ExponentialBoostLatitudeCorrectionHumidityScaling model.

v0.44.1

Breaking changes

• By default, call xr.open_mfdataset with lock=False in the MetDataSource.open_dataset method. This helps alleviate a dask threading issue similar to this GitHub issue.

Fixes

• Support MetDataset source in the HistogramMatching humidity scaling model. Previously only GeoVectorDataset sources were explicitly supported.
• Replace np.gradient with dask.array.gradient in the tau_cirrus module. This ensures that the computation is done lazily for dask-backed arrays.
• Round to 6 digits in the polygon.determine_buffer function. This avoid unnecessary warnings for rounding errors.
• Fix type hint for opencv-python 4.8.0.74.

Internals

• Take more care with float and int types in the contrail_properties module. Prefer np.clip to np.where or np.maximum for clipping values.
• Support air_temperature in CocipGrid verbose formation outputs.
• Remove pytest-timeout dev dependency.

v0.44.0

Support for the Poll-Schumann aircraft performance model.

Features

• Implement a basic working version of the Poll-Schumann (PS) aircraft performance model. This is experimental and may undergo revision in future releases. The PS Model currently supports the following 53 aircraft types:

  • A30B
  • A306
  • A310
  • A313
  • A318
  • A319
  • A320
  • A321
  • A332
  • A333
  • A342
  • A343
  • A345
  • A346
  • A359
  • A388
  • B712
  • B732
  • B733
  • B734
  • B735
  • B736
  • B737
  • B738
  • B739
  • B742
  • B743
  • B744
  • B748
  • B752
  • B753
  • B762
  • B763
  • B764
  • B77L
  • B772
  • B77W
  • B773
  • B788
  • B789
  • E135
  • E145
  • E170
  • E195
  • MD82
  • MD83
  • GLF5
  • CRJ9
  • DC93
  • RJ1H
  • B722
  • A20N
  • A21N

  The "gridded" version of this model is not yet implemented. This will be added in a future release.

• Improve the runtime of instantiating the Emissions model by a factor of 10-15x. This translates to a time savings of several hundred milliseconds on modern hardware. This improvement is achieved by more efficient parsing of the underlying static data and by deferring the construction of the interpolation artifacts until they are needed.

• Automatically use a default engine type from the aircraft type in the Emissions model if an engine_uid parameter is not included on the source. This itself is configurable via the use_default_engine_uid parameter on the Emissions model. The default mappings from aircraft types to engines is included in pycontrails/models/emissions/static/default-engine-uids.csv.

Breaking changes

• Remove the Aircraft dataclass from Flight instantiation. Any code previously using this should instead directly pass additional attrs to the Flight constructor.
• The load_factor is now required in AircraftPerformance models. The global DEFAULT_LOAD_FACTOR constant in pycontrails.models.aircraft_performance provides a reasonable default. This is currently set to 0.7.
• Use a takeoff_mass parameter in AircraftPerformance models if provided in the source.attrs data.
• No longer use a reference mass ref_mass in AircraftPerformance models. This is replaced by the takeoff_mass parameter if provided, or calculated from operating empty operating mass, max payload mass, total fuel consumption mass, reserve fuel mass, and the load factor.

Fixes

• Remove the fuel parameter from the Emissions model. This is inferred directly from the source parameter in Emissions.eval.
• Fix edge cases in the jet.reserve_fuel_requirements implementation. The previous version would return nan for some combinations of fuel_flow and segment_phase variables.
• Fix a spelling mistake: units.kelvin_to_celcius -> units.kelvin_to_celsius.

Internals

• Use ruff in place of pydocstyle for linting docstrings.
• Use ruff in place of isort for sorting imports.
• Update the AircraftPerformance template based on the patterns used in the new PSModel class. This may change again in the future.

v0.43.0

Support experimental interpolation against gridded specific humidity. Add new data-driven humidity scaling models.

Features

• Add new experimental interpolation_q_method field to the ModelParams data class. This parameter controls the interpolation methodology when interpolation against gridded specific humidity. The possible values are:

  • None: Interpolate linearly against specific humidity. This is the default behavior and is the same as the previous behavior.
  • "cubic-spline": Apply cubic-spline scaling to the interpolation table vertical coordinate before interpolating linearly against specific humidity.
  • "log-q-log-p": Interpolate in the log-log domain against specific humidity and pressure.

  This interpolation parameter is used when calling pycontrails.core.models.interpolate_met. It can also be used directly with the new lower-level pycontrails.core.models.interpolate_gridded_specific_humidity function.

• Add new experimental HistogramMatching humidity scaling model to match RHi values against IAGOS observations. The previous HistogramMatchingWithEckel scaling is still available when working with ERA5 ensemble members.

• Add new tutorial discussing the new specific humidity interpolation methodology.

Breaking changes

• Add an optional q_method parameter to the pycontrails.core.models.interpolate_met function. The default value None agrees with the previous behavior.
• Change function signatures in the cocip.py module for consistency. The interp_kwargs parameter is now unpacked in the calc_timestep_meterology signature. Rename kwargs to interp_kwargs where appropriate.
• Remove the cache_size parameter in MetDataset.from_zarr. Previously this parameter allowed the user to wrap the Zarr store in a LRUCacheStore to improve performance. Changes to Zarr internals have broken this approach. Custom Zarr patterns should now be handled outside of pycontrails.

Fixes

• Recompute and extend quantiles for histogram matching humidity scaling. Quantiles are now available for each combination of q_method and the following ERA5 data products: reanalysis and ensemble members 0-9. This data is available as a parquet file and is packaged with pycontrails.
• Fix the precomputed Eckel coefficients. Previous values where computed for different interpolation assumptions and were not correct for the default interpolation method.
• Clip the scaled humidity values computed by the humidity_scaling.eckel_scaling function to ensure that they are non-negative. Previously, both relative and specific humidity values arising from Eckel scaling could be negative.
• Handle edge case of all NaN values in the T_critical_sac function in the sac.py module.
• Avoid extraneous copy when calling VectorDataset.sum.
• Officially support numpy v1.25.0.
• Set a pytest-timeout limit for tests in tests/unit/test_ecmwf.py to avoid hanging tests.
• Add forecast_step parameter to the ACCF model.

Internals

• Refactor auxillary functions used by HistogramMatchingWithEckel to better isolated histogram matching from Eckel scaling.
• Refactor intersect_met method in pycontrails.core.models to handle experimental q_method parameter.
• Include a q_method field in Model.interp_kwargs.
• Include precomputed humidity lapse rate values in the new pycontrails.core.models._load_spline function.
• Move the humidity_scaling.py module into its own subdirectory within pycontrails/models.

v0.42.2

This is a re-release of v0.42.1, which didn't make it to PyPI. The release notes from v0.42.1 are copied below.

Features

• Add new HistogramMatchingWithEckel experimental humidity scaling model. This is still a work in progress.
• Add new Flight.fit_altitude method which uses piecewise linear fitting to smooth a flight profile.
• Add new pycontrails.core.flightplan module for parsing ATC flight plans between string and dictionary representations.
• Add new airports and flightplan examples.

Breaking changes

• No longer attach empty fields "sdr", "rsr", "olr", "rf_sw", "rf_lw", "rf_net" onto the source parameter in Cocip.eval when the flight doesn't generate any persistent contrails.
• Remove params humidity_scaling, rhi_adj_uncertainty, and rhi_boost_exponent_uncertainty from CocipUncertaintyParams.
• Change the default value for parallel from True to False in xr.open_mfdataset. This can be overridden by setting the xr_kwargs parameter in ERA5.open_metdataset.

Fixes

• Fix a unit test (test_dtypes.py::test_issr_sac_grid_output) that occasionally hangs. There may be another test in test_ecmwf.py that suffers from the same issue.
• Fix issue encountered in Cocip.eval when concatenating contrails with inconsistent values for _out_of_bounds. This is only relevant when running the model with the experimental parameter interpolation_use_indices=True.
• Add a Fleet.max_distance_gap property. The previous property on the Flight class was not applicable to Fleet instances.
• Fix warning in Flight class to correctly suggest adding kwarg drop_duplicated_times.
• Fix an issue in the VectorDataset constructor with a data parameter of type pd.DataFrame. Previously, time data was rewritten to the underlying DataFrame. This could cause copy-on-write issues if the DataFrame was a view of another DataFrame. This is now avoided.

Internals

• When possible, replace type hints np.ndarray -> np.typing.NDArray[np.float_] in the cocip, cocip_params, cocip_uncertainty, radiative_forcing, and wake_vortex modules.
• Slight performance enhancements in the radiative_forcing module.
• Change the default value of u_wind and v_wind from None to 0 in Flight.segment_true_airspeed. This makes more sense semantically.

v0.42.1

Features

• Add new HistogramMatchingWithEckel experimental humidity scaling model. This is still a work in progress.
• Add new Flight.fit_altitude method which uses piecewise linear fitting to smooth a flight profile.
• Add new pycontrails.core.flightplan module for parsing ATC flight plans between string and dictionary representations.
• Add new airports and flightplan examples.

Breaking changes

• No longer attach empty fields "sdr", "rsr", "olr", "rf_sw", "rf_lw", "rf_net" onto the source parameter in Cocip.eval when the flight doesn't generate any persistent contrails.
• Remove params humidity_scaling, rhi_adj_uncertainty, and rhi_boost_exponent_uncertainty from CocipUncertaintyParams.
• Change the default value for parallel from True to False in xr.open_mfdataset. This can be overridden by setting the xr_kwargs parameter in ERA5.open_metdataset.

Fixes

• Fix a unit test (test_dtypes.py::test_issr_sac_grid_output) that occasionally hangs. There may be another test in test_ecmwf.py that suffers from the same issue.
• Fix issue encountered in Cocip.eval when concatenating contrails with inconsistent values for _out_of_bounds. This is only relevant when running the model with the experimental parameter interpolation_use_indices=True.
• Add a Fleet.max_distance_gap property. The previous property on the Flight class was not applicable to Fleet instances.
• Fix warning in Flight class to correctly suggest adding kwarg drop_duplicated_times.
• Fix an issue in the VectorDataset constructor with a data parameter of type pd.DataFrame. Previously, time data was rewritten to the underlying DataFrame. This could cause copy-on-write issues if the DataFrame was a view of another DataFrame. This is now avoided.

Internals

• When possible, replace type hints np.ndarray -> np.typing.NDArray[np.float_] in the cocip, cocip_params, cocip_uncertainty, radiative_forcing, and wake_vortex modules.
• Slight performance enhancements in the radiative_forcing module.
• Change the default value of u_wind and v_wind from None to 0 in Flight.segment_true_airspeed. This makes more sense semantically.