Trajan demo

From OpenDrift 2.0, analysis and plotting of results from OpenDrift simulations will be handled by a new, standalone package: Trajan https://github.com/OpenDrift/trajan

This example creates a test dataset, and demonstrates its anlysis using Trajan

import os
from datetime import datetime, timedelta
import matplotlib.pyplot as plt
import xarray as xr
import trajan as ta
from opendrift import test_data_folder as tdf
from opendrift.readers import reader_netCDF_CF_generic
from opendrift.models.openoil import OpenOil

Create test dataset with OpenDrift

o = OpenOil(loglevel=20)

# Add forcing
reader_arome = reader_netCDF_CF_generic.Reader(tdf +
    '16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc')
reader_norkyst = reader_netCDF_CF_generic.Reader(tdf +
    '16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc')
o.add_reader([reader_norkyst, reader_arome])

# Seeding some particles
o.seed_elements(lon=4.4, lat=60.1, radius=1000, number=1000,
                time=reader_arome.start_time)

# Running model
o.run(end_time=reader_norkyst.end_time, outfile='openoil.nc')

17:01:34 INFO    opendrift:569: OpenDriftSimulation initialised (version 1.14.11 / v1.14.12-66-g07283eb)
17:01:34 INFO    opendrift.readers:67: Opening file with xr.open_dataset
17:01:35 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'time': 'time', 'x': 'x', 'y': 'y'}
17:01:35 INFO    opendrift.readers:67: Opening file with xr.open_dataset
17:01:35 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'X', 'y': 'Y', 'z': 'depth', 'time': 'time'}
17:01:35 INFO    opendrift.models.openoil.openoil:1720: Oil type not specified, using default: GENERIC BUNKER C
17:01:35 INFO    opendrift.models.openoil.adios.dirjs:86: Querying ADIOS database for oil: GENERIC BUNKER C
17:01:35 INFO    opendrift.models.openoil.openoil:1731: Using density 988.1 and viscosity 0.021692333877975332 of oiltype GENERIC BUNKER C
17:01:35 INFO    opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
17:01:42 INFO    opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_surface_height: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    upward_sea_water_velocity: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_significant_height: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_x_velocity: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_y_velocity: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_period_at_variance_spectral_density_maximum: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_ice_area_fraction: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_ice_x_velocity: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_ice_y_velocity: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_water_temperature: 10.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_water_salinity: 34.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    sea_floor_depth_below_sea_level: 10000.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    horizontal_diffusivity: 0.000000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    ocean_vertical_diffusivity: 0.020000
17:01:42 INFO    opendrift.models.basemodel.environment:230:    ocean_mixed_layer_thickness: 50.000000
17:01:42 INFO    opendrift:1911: Skipping environment variable upward_sea_water_velocity because of condition ['drift:vertical_advection', 'is', False]
17:01:42 INFO    opendrift:1922: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
17:01:42 INFO    opendrift:1922: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
17:01:42 INFO    opendrift:958: Using existing reader for land_binary_mask to move elements to ocean
17:01:42 INFO    opendrift:990: All points are in ocean
17:01:42 INFO    opendrift.models.openoil.openoil:697: Oil-water surface tension is 0.035935 Nm
17:01:42 INFO    opendrift.models.openoil.openoil:710: Max water fraction not available for GENERIC BUNKER C, using default
17:01:42 INFO    opendrift:2238: 2015-11-16 00:00:00 - step 1 of 66 - 1000 active elements (0 deactivated)
17:01:43 INFO    opendrift:2238: 2015-11-16 01:00:00 - step 2 of 66 - 1000 active elements (0 deactivated)
17:01:43 INFO    opendrift:2238: 2015-11-16 02:00:00 - step 3 of 66 - 1000 active elements (0 deactivated)
17:01:43 INFO    opendrift:2238: 2015-11-16 03:00:00 - step 4 of 66 - 1000 active elements (0 deactivated)
17:01:43 INFO    opendrift:2238: 2015-11-16 04:00:00 - step 5 of 66 - 1000 active elements (0 deactivated)
17:01:43 INFO    opendrift:2238: 2015-11-16 05:00:00 - step 6 of 66 - 1000 active elements (0 deactivated)
17:01:43 INFO    opendrift:2238: 2015-11-16 06:00:00 - step 7 of 66 - 1000 active elements (0 deactivated)
17:01:44 INFO    opendrift:2238: 2015-11-16 07:00:00 - step 8 of 66 - 1000 active elements (0 deactivated)
17:01:44 INFO    opendrift:2238: 2015-11-16 08:00:00 - step 9 of 66 - 1000 active elements (0 deactivated)
17:01:44 INFO    opendrift:2238: 2015-11-16 09:00:00 - step 10 of 66 - 1000 active elements (0 deactivated)
17:01:44 INFO    opendrift:2238: 2015-11-16 10:00:00 - step 11 of 66 - 1000 active elements (0 deactivated)
17:01:44 INFO    opendrift:2238: 2015-11-16 11:00:00 - step 12 of 66 - 1000 active elements (0 deactivated)
17:01:44 INFO    opendrift:2238: 2015-11-16 12:00:00 - step 13 of 66 - 1000 active elements (0 deactivated)
17:01:45 INFO    opendrift:2238: 2015-11-16 13:00:00 - step 14 of 66 - 1000 active elements (0 deactivated)
17:01:45 INFO    opendrift:2238: 2015-11-16 14:00:00 - step 15 of 66 - 1000 active elements (0 deactivated)
17:01:45 INFO    opendrift:2238: 2015-11-16 15:00:00 - step 16 of 66 - 1000 active elements (0 deactivated)
17:01:45 INFO    opendrift:2238: 2015-11-16 16:00:00 - step 17 of 66 - 1000 active elements (0 deactivated)
17:01:45 INFO    opendrift:2238: 2015-11-16 17:00:00 - step 18 of 66 - 1000 active elements (0 deactivated)
17:01:45 INFO    opendrift:2238: 2015-11-16 18:00:00 - step 19 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-16 19:00:00 - step 20 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-16 20:00:00 - step 21 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-16 21:00:00 - step 22 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-16 22:00:00 - step 23 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-16 23:00:00 - step 24 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-17 00:00:00 - step 25 of 66 - 1000 active elements (0 deactivated)
17:01:46 INFO    opendrift:2238: 2015-11-17 01:00:00 - step 26 of 66 - 1000 active elements (0 deactivated)
17:01:46 WARNING opendrift.readers.basereader.structured:324: Data block from /root/project/tests/test_data/16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc not large enough to cover element positions within timestep. Buffer size (8) must be increased. See `Variables.set_buffer_size`.
17:01:47 INFO    opendrift:2238: 2015-11-17 02:00:00 - step 27 of 66 - 1000 active elements (0 deactivated)
17:01:47 WARNING opendrift.readers.basereader.structured:324: Data block from /root/project/tests/test_data/16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc not large enough to cover element positions within timestep. Buffer size (4) must be increased. See `Variables.set_buffer_size`.
17:01:47 INFO    opendrift:2238: 2015-11-17 03:00:00 - step 28 of 66 - 1000 active elements (0 deactivated)
17:01:47 INFO    opendrift:2238: 2015-11-17 04:00:00 - step 29 of 66 - 1000 active elements (0 deactivated)
17:01:47 INFO    opendrift:2238: 2015-11-17 05:00:00 - step 30 of 66 - 1000 active elements (0 deactivated)
17:01:47 INFO    opendrift:2238: 2015-11-17 06:00:00 - step 31 of 66 - 996 active elements (4 deactivated)
17:01:47 INFO    opendrift:2238: 2015-11-17 07:00:00 - step 32 of 66 - 995 active elements (5 deactivated)
17:01:47 INFO    opendrift:2238: 2015-11-17 08:00:00 - step 33 of 66 - 986 active elements (14 deactivated)
17:01:48 INFO    opendrift:2238: 2015-11-17 09:00:00 - step 34 of 66 - 960 active elements (40 deactivated)
17:01:48 INFO    opendrift:2238: 2015-11-17 10:00:00 - step 35 of 66 - 923 active elements (77 deactivated)
17:01:48 INFO    opendrift:2238: 2015-11-17 11:00:00 - step 36 of 66 - 879 active elements (121 deactivated)
17:01:48 INFO    opendrift:2238: 2015-11-17 12:00:00 - step 37 of 66 - 827 active elements (173 deactivated)
17:01:48 INFO    opendrift:2238: 2015-11-17 13:00:00 - step 38 of 66 - 800 active elements (200 deactivated)
17:01:48 INFO    opendrift:2238: 2015-11-17 14:00:00 - step 39 of 66 - 778 active elements (222 deactivated)
17:01:49 INFO    opendrift:2238: 2015-11-17 15:00:00 - step 40 of 66 - 715 active elements (285 deactivated)
17:01:49 INFO    opendrift:2238: 2015-11-17 16:00:00 - step 41 of 66 - 653 active elements (347 deactivated)
17:01:49 INFO    opendrift:2238: 2015-11-17 17:00:00 - step 42 of 66 - 600 active elements (400 deactivated)
17:01:49 INFO    opendrift:2238: 2015-11-17 18:00:00 - step 43 of 66 - 522 active elements (478 deactivated)
17:01:49 INFO    opendrift:2238: 2015-11-17 19:00:00 - step 44 of 66 - 478 active elements (522 deactivated)
17:01:49 INFO    opendrift:2238: 2015-11-17 20:00:00 - step 45 of 66 - 368 active elements (632 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-17 21:00:00 - step 46 of 66 - 317 active elements (683 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-17 22:00:00 - step 47 of 66 - 294 active elements (706 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-17 23:00:00 - step 48 of 66 - 272 active elements (728 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-18 00:00:00 - step 49 of 66 - 258 active elements (742 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-18 01:00:00 - step 50 of 66 - 248 active elements (752 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-18 02:00:00 - step 51 of 66 - 244 active elements (756 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-18 03:00:00 - step 52 of 66 - 240 active elements (760 deactivated)
17:01:50 INFO    opendrift:2238: 2015-11-18 04:00:00 - step 53 of 66 - 236 active elements (764 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 05:00:00 - step 54 of 66 - 234 active elements (766 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 06:00:00 - step 55 of 66 - 226 active elements (774 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 07:00:00 - step 56 of 66 - 219 active elements (781 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 08:00:00 - step 57 of 66 - 214 active elements (786 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 09:00:00 - step 58 of 66 - 212 active elements (788 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 10:00:00 - step 59 of 66 - 212 active elements (788 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 11:00:00 - step 60 of 66 - 211 active elements (789 deactivated)
17:01:51 INFO    opendrift:2238: 2015-11-18 12:00:00 - step 61 of 66 - 211 active elements (789 deactivated)
17:01:52 INFO    opendrift:2238: 2015-11-18 13:00:00 - step 62 of 66 - 209 active elements (791 deactivated)
17:01:52 INFO    opendrift:2238: 2015-11-18 14:00:00 - step 63 of 66 - 206 active elements (794 deactivated)
17:01:52 INFO    opendrift:2238: 2015-11-18 15:00:00 - step 64 of 66 - 206 active elements (794 deactivated)
17:01:52 INFO    opendrift:2238: 2015-11-18 16:00:00 - step 65 of 66 - 205 active elements (795 deactivated)
17:01:52 INFO    opendrift:2238: 2015-11-18 17:00:00 - step 66 of 66 - 205 active elements (795 deactivated)

<xarray.Dataset> Size: 13MB
Dimensions:                                                                              (
                                                                                          trajectory: 1000,
                                                                                          time: 67)
Coordinates:
  * trajectory                                                                           (trajectory) int32 4kB ...
  * time                                                                                 (time) datetime64[ns] 536B ...
Data variables: (12/44)
    status                                                                               (trajectory, time) float64 536kB ...
    moving                                                                               (trajectory, time) float64 536kB ...
    age_seconds                                                                          (trajectory, time) float32 268kB ...
    origin_marker                                                                        (trajectory, time) float64 536kB ...
    lon                                                                                  (trajectory, time) float32 268kB ...
    lat                                                                                  (trajectory, time) float32 268kB ...
    ...                                                                                   ...
    sea_water_salinity                                                                   (trajectory, time) float32 268kB ...
    sea_floor_depth_below_sea_level                                                      (trajectory, time) float32 268kB ...
    horizontal_diffusivity                                                               (trajectory, time) float32 268kB ...
    ocean_vertical_diffusivity                                                           (trajectory, time) float32 268kB ...
    land_binary_mask                                                                     (trajectory, time) float32 268kB ...
    ocean_mixed_layer_thickness                                                          (trajectory, time) float32 268kB ...
Attributes: (12/167)
    Conventions:                                                             ...
    standard_name_vocabulary:                                                ...
    featureType:                                                             ...
    title:                                                                   ...
    summary:                                                                 ...
    keywords:                                                                ...
    ...                                                                                                               ...
    geospatial_lon_units:                                                    ...
    geospatial_lon_resolution:                                               ...
    runtime:                                                                 ...
    geospatial_vertical_min:                                                 ...
    geospatial_vertical_max:                                                 ...
    geospatial_vertical_positive:                                            ...

xarray.Dataset

• Dimensions:
  • trajectory: 1000
  • time: 67
• Coordinates: (2)
  • trajectory
    (trajectory)
    int32
    0 1 2 3 4 5 ... 995 996 997 998 999

    cf_role :

    trajectory_id

    array([  0,   1,   2, ..., 997, 998, 999], shape=(1000,), dtype=int32)

  • time
    (time)
    datetime64[ns]
    2015-11-16 ... 2015-11-18T18:00:00

    standard_name :

    time

    long_name :

    time

    array(['2015-11-16T00:00:00.000000000', '2015-11-16T01:00:00.000000000',
           '2015-11-16T02:00:00.000000000', '2015-11-16T03:00:00.000000000',
           '2015-11-16T04:00:00.000000000', '2015-11-16T05:00:00.000000000',
           '2015-11-16T06:00:00.000000000', '2015-11-16T07:00:00.000000000',
           '2015-11-16T08:00:00.000000000', '2015-11-16T09:00:00.000000000',
           '2015-11-16T10:00:00.000000000', '2015-11-16T11:00:00.000000000',
           '2015-11-16T12:00:00.000000000', '2015-11-16T13:00:00.000000000',
           '2015-11-16T14:00:00.000000000', '2015-11-16T15:00:00.000000000',
           '2015-11-16T16:00:00.000000000', '2015-11-16T17:00:00.000000000',
           '2015-11-16T18:00:00.000000000', '2015-11-16T19:00:00.000000000',
           '2015-11-16T20:00:00.000000000', '2015-11-16T21:00:00.000000000',
           '2015-11-16T22:00:00.000000000', '2015-11-16T23:00:00.000000000',
           '2015-11-17T00:00:00.000000000', '2015-11-17T01:00:00.000000000',
           '2015-11-17T02:00:00.000000000', '2015-11-17T03:00:00.000000000',
           '2015-11-17T04:00:00.000000000', '2015-11-17T05:00:00.000000000',
           '2015-11-17T06:00:00.000000000', '2015-11-17T07:00:00.000000000',
           '2015-11-17T08:00:00.000000000', '2015-11-17T09:00:00.000000000',
           '2015-11-17T10:00:00.000000000', '2015-11-17T11:00:00.000000000',
           '2015-11-17T12:00:00.000000000', '2015-11-17T13:00:00.000000000',
           '2015-11-17T14:00:00.000000000', '2015-11-17T15:00:00.000000000',
           '2015-11-17T16:00:00.000000000', '2015-11-17T17:00:00.000000000',
           '2015-11-17T18:00:00.000000000', '2015-11-17T19:00:00.000000000',
           '2015-11-17T20:00:00.000000000', '2015-11-17T21:00:00.000000000',
           '2015-11-17T22:00:00.000000000', '2015-11-17T23:00:00.000000000',
           '2015-11-18T00:00:00.000000000', '2015-11-18T01:00:00.000000000',
           '2015-11-18T02:00:00.000000000', '2015-11-18T03:00:00.000000000',
           '2015-11-18T04:00:00.000000000', '2015-11-18T05:00:00.000000000',
           '2015-11-18T06:00:00.000000000', '2015-11-18T07:00:00.000000000',
           '2015-11-18T08:00:00.000000000', '2015-11-18T09:00:00.000000000',
           '2015-11-18T10:00:00.000000000', '2015-11-18T11:00:00.000000000',
           '2015-11-18T12:00:00.000000000', '2015-11-18T13:00:00.000000000',
           '2015-11-18T14:00:00.000000000', '2015-11-18T15:00:00.000000000',
           '2015-11-18T16:00:00.000000000', '2015-11-18T17:00:00.000000000',
           '2015-11-18T18:00:00.000000000'], dtype='datetime64[ns]')

• Data variables: (44)
  • status
    (trajectory, time)
    float64
    ...

    valid_range :

    [0 1]

    flag_values :

    [0 1]

    flag_meanings :

    active stranded

    [67000 values with dtype=float64]

  • moving
    (trajectory, time)
    float64
    ...

    minval :

    0

    maxval :

    1

    [67000 values with dtype=float64]

  • age_seconds
    (trajectory, time)
    float32
    ...

    units :

    s

    minval :

    0.0

    maxval :

    237600.0

    [67000 values with dtype=float32]

  • origin_marker
    (trajectory, time)
    float64
    ...

    unit :

    description :

    An integer kept constant during the simulation. Different values may be used for different seedings, to separate elements during analysis. With GUI, only a single seeding is possible.

    flag_values :

    0

    flag_meanings :

    Seed_0

    minval :

    0

    maxval :

    0

    [67000 values with dtype=float64]

  • lon
    (trajectory, time)
    float32
    ...

    units :

    degrees_east

    standard_name :

    longitude

    long_name :

    longitude

    axis :

    X

    minval :

    4.059588

    maxval :

    5.0068555

    [67000 values with dtype=float32]

  • lat
    (trajectory, time)
    float32
    ...

    units :

    degrees_north

    standard_name :

    latitude

    long_name :

    latitude

    axis :

    Y

    minval :

    60.07312

    maxval :

    61.547577

    [67000 values with dtype=float32]

  • z
    (trajectory, time)
    float32
    ...

    units :

    m

    standard_name :

    z

    long_name :

    vertical position

    axis :

    Z

    positive :

    up

    minval :

    -49.660835

    maxval :

    0.0

    [67000 values with dtype=float32]

  • wind_drift_factor
    (trajectory, time)
    float32
    ...

    units :

    1

    description :

    Elements at the ocean surface are moved by this fraction of the wind vector, in addition to currents and Stokes drift

    minval :

    0.03

    maxval :

    0.03

    [67000 values with dtype=float32]

  • current_drift_factor
    (trajectory, time)
    float32
    ...

    units :

    1

    description :

    Elements are moved with this fraction of the current vector, in addition to currents and Stokes drift

    minval :

    1.0

    maxval :

    1.0

    [67000 values with dtype=float32]

  • terminal_velocity
    (trajectory, time)
    float32
    ...

    units :

    m/s

    description :

    Terminal rise/sinking velocity (buoyancy) in the ocean column

    minval :

    0.0

    maxval :

    0.053044997

    [67000 values with dtype=float32]

  • mass_oil
    (trajectory, time)
    float32
    ...

    units :

    kg

    minval :

    0.035335053

    maxval :

    0.9881

    [67000 values with dtype=float32]

  • viscosity
    (trajectory, time)
    float32
    ...

    units :

    m2/s

    description :

    Kinematic viscosity of oil (emulsion)

    minval :

    0.021692334

    maxval :

    4.6706653

    [67000 values with dtype=float32]

  • density
    (trajectory, time)
    float32
    ...

    units :

    kg/m^3

    minval :

    988.1

    maxval :

    989.3333

    [67000 values with dtype=float32]

  • bulltime
    (trajectory, time)
    float32
    ...

    units :

    s

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • interfacial_area
    (trajectory, time)
    float32
    ...

    units :

    m2

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • mass_dispersed
    (trajectory, time)
    float32
    ...

    units :

    kg

    minval :

    0.0

    maxval :

    0.9182068

    [67000 values with dtype=float32]

  • mass_evaporated
    (trajectory, time)
    float32
    ...

    units :

    kg

    minval :

    0.0

    maxval :

    0.04999069

    [67000 values with dtype=float32]

  • mass_biodegraded
    (trajectory, time)
    float32
    ...

    units :

    kg

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • biodegradation_half_time_droplet
    (trajectory, time)
    float32
    ...

    units :

    Days

    description :

    Biodegradation half time in days for submerged oil droplets

    minval :

    1.0

    maxval :

    1.0

    [67000 values with dtype=float32]

  • biodegradation_half_time_slick
    (trajectory, time)
    float32
    ...

    units :

    Days

    description :

    Biodegradation half time in days for surface oil slick

    minval :

    3.0

    maxval :

    3.0

    [67000 values with dtype=float32]

  • fraction_evaporated
    (trajectory, time)
    float32
    ...

    units :

    1

    minval :

    0.0

    maxval :

    0.5106912

    [67000 values with dtype=float32]

  • water_fraction
    (trajectory, time)
    float32
    ...

    units :

    1

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • oil_film_thickness
    (trajectory, time)
    float32
    ...

    units :

    m

    minval :

    0.001

    maxval :

    0.001

    [67000 values with dtype=float32]

  • diameter
    (trajectory, time)
    float32
    ...

    units :

    m

    minval :

    0.0

    maxval :

    0.0029962154

    [67000 values with dtype=float32]

  • x_sea_water_velocity
    (trajectory, time)
    float32
    ...

    minval :

    -0.9292532

    maxval :

    0.6805134

    [67000 values with dtype=float32]

  • y_sea_water_velocity
    (trajectory, time)
    float32
    ...

    minval :

    -0.59841686

    maxval :

    1.4467301

    [67000 values with dtype=float32]

  • x_wind
    (trajectory, time)
    float32
    ...

    minval :

    -15.430905

    maxval :

    18.691193

    [67000 values with dtype=float32]

  • y_wind
    (trajectory, time)
    float32
    ...

    minval :

    -7.352772

    maxval :

    23.831951

    [67000 values with dtype=float32]

  • sea_surface_height
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_surface_wave_significant_height
    (trajectory, time)
    float32
    ...

    minval :

    0.0067981407

    maxval :

    13.999928

    [67000 values with dtype=float32]

  • sea_surface_wave_stokes_drift_x_velocity
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_surface_wave_stokes_drift_y_velocity
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_surface_wave_period_at_variance_spectral_density_maximum
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment
    (trajectory, time)
    float32
    ...

    minval :

    0.4491844

    maxval :

    20.384144

    [67000 values with dtype=float32]

  • sea_ice_area_fraction
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_ice_x_velocity
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_ice_y_velocity
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • sea_water_temperature
    (trajectory, time)
    float32
    ...

    minval :

    10.0

    maxval :

    283.15

    [67000 values with dtype=float32]

  • sea_water_salinity
    (trajectory, time)
    float32
    ...

    minval :

    34.0

    maxval :

    34.0

    [67000 values with dtype=float32]

  • sea_floor_depth_below_sea_level
    (trajectory, time)
    float32
    ...

    minval :

    10000.0

    maxval :

    10000.0

    [67000 values with dtype=float32]

  • horizontal_diffusivity
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • ocean_vertical_diffusivity
    (trajectory, time)
    float32
    ...

    minval :

    0.02

    maxval :

    0.02

    [67000 values with dtype=float32]

  • land_binary_mask
    (trajectory, time)
    float32
    ...

    minval :

    0.0

    maxval :

    0.0

    [67000 values with dtype=float32]

  • ocean_mixed_layer_thickness
    (trajectory, time)
    float32
    ...

    minval :

    50.0

    maxval :

    50.0

    [67000 values with dtype=float32]

• Attributes: (167)

  Conventions :

  CF-1.11, ACDD-1.3

  standard_name_vocabulary :

  CF Standard Name Table v85

  featureType :

  trajectory

  title :

  OpenDrift trajectory simulation

  summary :

  Output from simulation with OpenDrift framework

  keywords :

  trajectory, drift, lagrangian, simulation

  history :

  Created 2026-10-26 17:01:42.905424

  date_created :

  2026-10-26T17:01:42.905439

  source :

  Output from simulation with OpenDrift

  model_url :

  https://github.com/OpenDrift/opendrift

  opendrift_class :

  OpenOil

  opendrift_module :

  opendrift.models.openoil.openoil

  readers :

  odict_keys(['/root/project/tests/test_data/16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc', '/root/project/tests/test_data/16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc', 'global_landmask'])

  time_coverage_start :

  2015-11-16 00:00:00

  time_step_calculation :

  1:00:00

  time_step_output :

  1:00:00

  config_environment:constant:x_sea_water_velocity :

  None

  config_environment:fallback:x_sea_water_velocity :

  None

  config_environment:constant:y_sea_water_velocity :

  None

  config_environment:fallback:y_sea_water_velocity :

  None

  config_environment:constant:x_wind :

  None

  config_environment:fallback:x_wind :

  None

  config_environment:constant:y_wind :

  None

  config_environment:fallback:y_wind :

  None

  config_environment:constant:sea_surface_height :

  None

  config_environment:fallback:sea_surface_height :

  0

  config_environment:constant:upward_sea_water_velocity :

  None

  config_environment:fallback:upward_sea_water_velocity :

  0

  config_environment:constant:sea_surface_wave_significant_height :

  None

  config_environment:fallback:sea_surface_wave_significant_height :

  0

  config_environment:constant:sea_surface_wave_stokes_drift_x_velocity :

  None

  config_environment:fallback:sea_surface_wave_stokes_drift_x_velocity :

  0

  config_environment:constant:sea_surface_wave_stokes_drift_y_velocity :

  None

  config_environment:fallback:sea_surface_wave_stokes_drift_y_velocity :

  0

  config_environment:constant:sea_surface_wave_period_at_variance_spectral_density_maximum :

  None

  config_environment:fallback:sea_surface_wave_period_at_variance_spectral_density_maximum :

  0

  config_environment:constant:sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment :

  None

  config_environment:fallback:sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment :

  0

  config_environment:constant:sea_ice_area_fraction :

  None

  config_environment:fallback:sea_ice_area_fraction :

  0

  config_environment:constant:sea_ice_x_velocity :

  None

  config_environment:fallback:sea_ice_x_velocity :

  0

  config_environment:constant:sea_ice_y_velocity :

  None

  config_environment:fallback:sea_ice_y_velocity :

  0

  config_environment:constant:sea_water_temperature :

  None

  config_environment:fallback:sea_water_temperature :

  10

  config_environment:constant:sea_water_salinity :

  None

  config_environment:fallback:sea_water_salinity :

  34

  config_environment:constant:sea_floor_depth_below_sea_level :

  None

  config_environment:fallback:sea_floor_depth_below_sea_level :

  10000

  config_environment:constant:horizontal_diffusivity :

  None

  config_environment:fallback:horizontal_diffusivity :

  0

  config_environment:constant:ocean_vertical_diffusivity :

  None

  config_environment:fallback:ocean_vertical_diffusivity :

  0.02

  config_environment:constant:land_binary_mask :

  None

  config_environment:fallback:land_binary_mask :

  None

  config_environment:constant:ocean_mixed_layer_thickness :

  None

  config_environment:fallback:ocean_mixed_layer_thickness :

  50

  config_general:use_auto_landmask :

  True

  config_drift:current_uncertainty :

  0.05

  config_drift:current_uncertainty_uniform :

  0

  config_drift:max_speed :

  1.3

  config_readers:max_number_of_fails :

  1

  config_general:simulation_name :

  config_general:coastline_action :

  stranding

  config_general:coastline_approximation_precision :

  0.001

  config_general:time_step_minutes :

  60

  config_general:time_step_output_minutes :

  None

  config_seed:ocean_only :

  True

  config_seed:number :

  1

  config_drift:max_age_seconds :

  None

  config_drift:advection_scheme :

  euler

  config_drift:profiles_depth :

  50

  config_drift:wind_uncertainty :

  0.5

  config_drift:relative_wind :

  False

  config_drift:deactivate_north_of :

  None

  config_drift:deactivate_south_of :

  None

  config_drift:deactivate_east_of :

  None

  config_drift:deactivate_west_of :

  None

  config_seed:origin_marker :

  0

  config_seed:z :

  0

  config_seed:wind_drift_factor :

  0.03

  config_seed:current_drift_factor :

  1

  config_seed:terminal_velocity :

  0.0

  config_seed:oil_film_thickness :

  0.001

  config_drift:vertical_advection :

  False

  config_drift:vertical_advection_at_surface :

  False

  config_drift:water_column_stretching :

  False

  config_drift:vertical_advection_correction :

  False

  config_drift:vertical_mixing :

  True

  config_drift:vertical_mixing_at_surface :

  False

  config_vertical_mixing:timestep :

  60

  config_vertical_mixing:diffusivitymodel :

  environment

  config_vertical_mixing:background_diffusivity :

  1.2e-05

  config_vertical_mixing:TSprofiles :

  False

  config_drift:wind_drift_depth :

  0.1

  config_drift:stokes_drift :

  True

  config_drift:stokes_drift_profile :

  Phillips

  config_drift:use_tabularised_stokes_drift :

  False

  config_drift:tabularised_stokes_drift_fetch :

  25000

  config_general:seafloor_action :

  lift_to_seafloor

  config_drift:truncate_ocean_model_below_m :

  None

  config_seed:seafloor :

  False

  config_seed:m3_per_hour :

  1

  config_seed:droplet_size_distribution :

  uniform

  config_seed:droplet_diameter_mu :

  0.001

  config_seed:droplet_diameter_sigma :

  0.0005

  config_seed:droplet_diameter_min_subsea :

  0.0005

  config_seed:droplet_diameter_max_subsea :

  0.005

  config_processes:dispersion :

  True

  config_processes:evaporation :

  True

  config_processes:emulsification :

  True

  config_processes:biodegradation :

  False

  config_biodegradation:method :

  Adcroft

  config_processes:update_oilfilm_thickness :

  False

  config_wave_entrainment:droplet_size_distribution :

  Johansen et al. (2015)

  config_wave_entrainment:entrainment_rate :

  Li et al. (2017)

  config_seed:oil_type :

  GENERIC BUNKER C

  opendrift_version :

  1.14.11

  seed_lon :

  4.4

  seed_lat :

  60.1

  seed_radius :

  1000.0

  seed_time :

  2015-11-16 00:00:00

  seed_number :

  1000.0

  seed_z :

  0.0

  seed_m3_per_hour :

  1.0

  seed_oiltype :

  GENERIC BUNKER C

  seed_geojson :

  {"features": [], "type": "FeatureCollection"}

  simulation_time :

  2026-10-26 17:01:42.920821

  reader_x_sea_water_velocity :

  ['/root/project/tests/test_data/16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc']

  reader_y_sea_water_velocity :

  ['/root/project/tests/test_data/16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc']

  reader_x_wind :

  ['/root/project/tests/test_data/16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc']

  reader_y_wind :

  ['/root/project/tests/test_data/16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc']

  reader_sea_surface_height :

  0

  reader_sea_surface_wave_significant_height :

  0

  reader_sea_surface_wave_stokes_drift_x_velocity :

  0

  reader_sea_surface_wave_stokes_drift_y_velocity :

  0

  reader_sea_surface_wave_period_at_variance_spectral_density_maximum :

  0

  reader_sea_surface_wave_mean_period_from_variance_spectral_density_second_frequency_moment :

  0

  reader_sea_ice_area_fraction :

  0

  reader_sea_ice_x_velocity :

  0

  reader_sea_ice_y_velocity :

  0

  reader_sea_water_temperature :

  10

  reader_sea_water_salinity :

  34

  reader_sea_floor_depth_below_sea_level :

  10000

  reader_horizontal_diffusivity :

  0

  reader_ocean_vertical_diffusivity :

  0.02

  reader_land_binary_mask :

  ['global_landmask']

  reader_ocean_mixed_layer_thickness :

  50

  time_coverage_end :

  2015-11-18 18:00:00

  time_coverage_duration :

  P2DT18H0M0S

  time_coverage_resolution :

  P0DT1H0M0S

  performance :

  -------------------- Reader performance: -------------------- /root/project/tests/test_data/16Nov2015_NorKyst_z_surface/norkyst800_subset_16Nov2015.nc 0:00:00.4 total 0:00:00.0 preparing 0:00:00.3 reading 0:00:00.0 interpolation 0:00:00.0 interpolation_time 0:00:00.1 rotating vectors 0:00:00.0 masking -------------------- /root/project/tests/test_data/16Nov2015_NorKyst_z_surface/arome_subset_16Nov2015.nc 0:00:00.3 total 0:00:00.0 preparing 0:00:00.2 reading 0:00:00.0 interpolation 0:00:00.0 interpolation_time 0:00:00.1 rotating vectors 0:00:00.0 masking -------------------- global_landmask 0:00:00.0 total 0:00:00.0 preparing 0:00:00.0 reading 0:00:00.0 masking -------------------- Performance: 18.1 total time 8.4 configuration 0.0 preparing main loop 0.0 moving elements to ocean 9.6 main loop 4.4 updating elements 0.5 oil weathering 0.0 updating viscosities 0.0 updating densities 0.4 evaporation 0.0 emulsification 0.0 dispersion 3.8 vertical mixing 0.0 cleaning up --------------------

  geospatial_bounds_crs :

  EPSG:4326

  geospatial_bounds_vertical_crs :

  EPSG:5831

  geospatial_lat_min :

  60.07312

  geospatial_lat_max :

  61.547577

  geospatial_lat_units :

  degrees_north

  geospatial_lat_resolution :

  point

  geospatial_lon_min :

  4.059588

  geospatial_lon_max :

  5.0068555

  geospatial_lon_units :

  degrees_east

  geospatial_lon_resolution :

  point

  runtime :

  0:00:18.172996

  geospatial_vertical_min :

  -49.660835

  geospatial_vertical_max :

  0.0

  geospatial_vertical_positive :

  up

Demonstrating analysis and visualisation of the output dataset, independently of OpenDrift code

if not os.path.exists('openoil.nc'):
    raise ValueError('Please run create_test_dataset.py first')

Importing a trajectory dataset from a simulation with OpenDrift decode_coords is needed so that lon and lat are not interpreted as coordinate variables

d = xr.open_dataset('openoil.nc', decode_coords=False)
# Requirement that status>=0 is needed since non-valid points are not masked in OpenDrift output
d = d.where(d.status>=0)  # only active particles

Displaying a basic plot of trajectories

d.traj.plot(land='mask')
ax = plt.gca()
ax.set_title('Adding custom title')
plt.show()

Demonstrating how the Xarray Dataset can be modified, allowing for more flexibility than can be provided through the plotting method of OpenDrift

Extracting only the first 100 elements, and every 4th output time steps:

dsub = d.isel(trajectory=range(0, 100), time=range(0, len(d.time), 4))
dsub.traj.plot(land='h')
plt.show()

With several plots on the same figure

d.traj.plot(color='red', alpha=0.01, land='mask')  # Plotting individual trajectories in red
dmean = d.mean('trajectory', skipna=True) # Overlaying a "mean" trajectory in black
dmean.traj.plot(color='k', linewidth=5)
# Showing the a sub-period of the mean trajectory in yellow
dmean.sel(time=slice('2015-11-17', '2015-11-17 12')).traj.plot(color='yellow', linewidth=5)
plt.tight_layout()
plt.show()

Cleaning up

os.remove('openoil.nc')