Reader boundary

Seeding elements around the border of a ocean model domain (NorKyst800) to demonstrate autmatic transition back and forth with another model covering a larger domain (Topaz).

from datetime import datetime
import numpy as np
from opendrift.readers import reader_netCDF_CF_generic
from opendrift.models.oceandrift import OceanDrift

o = OceanDrift(loglevel=20)  # Set loglevel to 0 for debug information

# Norkyst
reader_norkyst = reader_netCDF_CF_generic.Reader('https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be')

# Topaz
reader_topaz = reader_netCDF_CF_generic.Reader('https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml')

o.add_reader([reader_norkyst, reader_topaz])
o.set_config('environment:fallback:land_binary_mask', 0)
o.set_config('drift:vertical_mixing', False)

13:56:45 INFO    opendrift:569: OpenDriftSimulation initialised (version 1.14.11 / v1.14.12-9-g6f1a4a0)
13:56:45 INFO    opendrift.readers:67: Opening file with xr.open_dataset
13:56:47 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'X', 'y': 'Y', 'z': 'depth', 'time': 'time'}
13:56:47 INFO    opendrift.readers.basereader:175: Variable x_sea_water_velocity will be rotated from eastward_sea_water_velocity
13:56:47 INFO    opendrift.readers.basereader:175: Variable y_sea_water_velocity will be rotated from northward_sea_water_velocity
13:56:47 INFO    opendrift.readers.basereader:175: Variable x_wind will be rotated from eastward_wind
13:56:47 INFO    opendrift.readers.basereader:175: Variable y_wind will be rotated from northward_wind
13:56:47 INFO    opendrift.readers:67: Opening file with xr.open_dataset
13:56:51 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'x', 'y': 'y', 'time': 'time'}

Seeding some particles

lons = np.linspace(5, 8, 50)
lats = np.linspace(69.8, 70.8, 50)
lons, lats = np.meshgrid(lons, lats)

Seed oil elements at defined position and time

o.seed_elements(lons, lats, radius=0, number=2500,
                time=datetime.now())

13:56:51 INFO    opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
13:56:57 INFO    opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
13:56:57 INFO    opendrift.models.basemodel.environment:230:    horizontal_diffusivity: 0.000000
13:56:57 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_significant_height: 0.000000
13:56:57 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_x_velocity: 0.000000
13:56:57 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_y_velocity: 0.000000
13:56:57 INFO    opendrift.models.basemodel.environment:230:    ocean_mixed_layer_thickness: 50.000000

Running model

o.run(steps=16*4, time_step=900, time_step_output=1800)

13:56:57 INFO    opendrift:1910: Skipping environment variable ocean_vertical_diffusivity because of condition ['drift:vertical_mixing', 'is', False]
13:56:57 INFO    opendrift:1910: Skipping environment variable ocean_mixed_layer_thickness because of condition ['drift:vertical_mixing', 'is', False]
13:56:57 INFO    opendrift:1921: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
13:56:57 INFO    opendrift:1921: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
13:56:57 INFO    opendrift:1929: Storing previous values of environment variable sea_surface_height because of condition ['drift:vertical_advection', 'is', True]
13:56:57 INFO    opendrift:958: Using existing reader for land_binary_mask to move elements to ocean
13:56:57 INFO    opendrift:989: All points are in ocean
13:56:57 INFO    opendrift:2237: 2026-09-10 13:56:51.532773 - step 1 of 64 - 2500 active elements (0 deactivated)
13:57:02 INFO    opendrift:2237: 2026-09-10 14:11:51.532773 - step 2 of 64 - 2500 active elements (0 deactivated)
13:57:03 INFO    opendrift:2237: 2026-09-10 14:26:51.532773 - step 3 of 64 - 2500 active elements (0 deactivated)
13:57:04 INFO    opendrift:2237: 2026-09-10 14:41:51.532773 - step 4 of 64 - 2500 active elements (0 deactivated)
13:57:04 INFO    opendrift:2237: 2026-09-10 14:56:51.532773 - step 5 of 64 - 2500 active elements (0 deactivated)
13:57:05 INFO    opendrift:2237: 2026-09-10 15:11:51.532773 - step 6 of 64 - 2500 active elements (0 deactivated)
13:57:07 INFO    opendrift:2237: 2026-09-10 15:26:51.532773 - step 7 of 64 - 2500 active elements (0 deactivated)
13:57:08 INFO    opendrift:2237: 2026-09-10 15:41:51.532773 - step 8 of 64 - 2500 active elements (0 deactivated)
13:57:08 INFO    opendrift:2237: 2026-09-10 15:56:51.532773 - step 9 of 64 - 2500 active elements (0 deactivated)
13:57:09 INFO    opendrift:2237: 2026-09-10 16:11:51.532773 - step 10 of 64 - 2500 active elements (0 deactivated)
13:57:11 INFO    opendrift:2237: 2026-09-10 16:26:51.532773 - step 11 of 64 - 2500 active elements (0 deactivated)
13:57:11 INFO    opendrift:2237: 2026-09-10 16:41:51.532773 - step 12 of 64 - 2500 active elements (0 deactivated)
13:57:12 INFO    opendrift:2237: 2026-09-10 16:56:51.532773 - step 13 of 64 - 2500 active elements (0 deactivated)
13:57:12 INFO    opendrift:2237: 2026-09-10 17:11:51.532773 - step 14 of 64 - 2500 active elements (0 deactivated)
13:57:15 INFO    opendrift:2237: 2026-09-10 17:26:51.532773 - step 15 of 64 - 2500 active elements (0 deactivated)
13:57:16 INFO    opendrift:2237: 2026-09-10 17:41:51.532773 - step 16 of 64 - 2500 active elements (0 deactivated)
13:57:16 INFO    opendrift:2237: 2026-09-10 17:56:51.532773 - step 17 of 64 - 2500 active elements (0 deactivated)
13:57:17 INFO    opendrift:2237: 2026-09-10 18:11:51.532773 - step 18 of 64 - 2500 active elements (0 deactivated)
13:57:19 INFO    opendrift:2237: 2026-09-10 18:26:51.532773 - step 19 of 64 - 2500 active elements (0 deactivated)
13:57:20 INFO    opendrift:2237: 2026-09-10 18:41:51.532773 - step 20 of 64 - 2500 active elements (0 deactivated)
13:57:20 INFO    opendrift:2237: 2026-09-10 18:56:51.532773 - step 21 of 64 - 2500 active elements (0 deactivated)
13:57:21 INFO    opendrift:2237: 2026-09-10 19:11:51.532773 - step 22 of 64 - 2500 active elements (0 deactivated)
13:57:23 INFO    opendrift:2237: 2026-09-10 19:26:51.532773 - step 23 of 64 - 2500 active elements (0 deactivated)
13:57:24 INFO    opendrift:2237: 2026-09-10 19:41:51.532773 - step 24 of 64 - 2500 active elements (0 deactivated)
13:57:24 INFO    opendrift:2237: 2026-09-10 19:56:51.532773 - step 25 of 64 - 2500 active elements (0 deactivated)
13:57:25 INFO    opendrift:2237: 2026-09-10 20:11:51.532773 - step 26 of 64 - 2500 active elements (0 deactivated)
13:57:28 INFO    opendrift:2237: 2026-09-10 20:26:51.532773 - step 27 of 64 - 2500 active elements (0 deactivated)
13:57:28 INFO    opendrift:2237: 2026-09-10 20:41:51.532773 - step 28 of 64 - 2500 active elements (0 deactivated)
13:57:29 INFO    opendrift:2237: 2026-09-10 20:56:51.532773 - step 29 of 64 - 2500 active elements (0 deactivated)
13:57:29 INFO    opendrift:2237: 2026-09-10 21:11:51.532773 - step 30 of 64 - 2500 active elements (0 deactivated)
13:57:32 INFO    opendrift:2237: 2026-09-10 21:26:51.532773 - step 31 of 64 - 2500 active elements (0 deactivated)
13:57:32 INFO    opendrift:2237: 2026-09-10 21:41:51.532773 - step 32 of 64 - 2500 active elements (0 deactivated)
13:57:33 INFO    opendrift:2237: 2026-09-10 21:56:51.532773 - step 33 of 64 - 2500 active elements (0 deactivated)
13:57:34 INFO    opendrift:2237: 2026-09-10 22:11:51.532773 - step 34 of 64 - 2500 active elements (0 deactivated)
13:57:36 INFO    opendrift:2237: 2026-09-10 22:26:51.532773 - step 35 of 64 - 2500 active elements (0 deactivated)
13:57:37 INFO    opendrift:2237: 2026-09-10 22:41:51.532773 - step 36 of 64 - 2500 active elements (0 deactivated)
13:57:37 INFO    opendrift:2237: 2026-09-10 22:56:51.532773 - step 37 of 64 - 2500 active elements (0 deactivated)
13:57:38 INFO    opendrift:2237: 2026-09-10 23:11:51.532773 - step 38 of 64 - 2500 active elements (0 deactivated)
13:57:40 INFO    opendrift:2237: 2026-09-10 23:26:51.532773 - step 39 of 64 - 2500 active elements (0 deactivated)
13:57:41 INFO    opendrift:2237: 2026-09-10 23:41:51.532773 - step 40 of 64 - 2500 active elements (0 deactivated)
13:57:42 INFO    opendrift:2237: 2026-09-10 23:56:51.532773 - step 41 of 64 - 2500 active elements (0 deactivated)
13:57:43 INFO    opendrift:2237: 2026-09-11 00:11:51.532773 - step 42 of 64 - 2500 active elements (0 deactivated)
13:57:45 INFO    opendrift:2237: 2026-09-11 00:26:51.532773 - step 43 of 64 - 2500 active elements (0 deactivated)
13:57:46 INFO    opendrift:2237: 2026-09-11 00:41:51.532773 - step 44 of 64 - 2500 active elements (0 deactivated)
13:57:46 INFO    opendrift:2237: 2026-09-11 00:56:51.532773 - step 45 of 64 - 2500 active elements (0 deactivated)
13:57:47 INFO    opendrift:2237: 2026-09-11 01:11:51.532773 - step 46 of 64 - 2500 active elements (0 deactivated)
13:57:50 INFO    opendrift:2237: 2026-09-11 01:26:51.532773 - step 47 of 64 - 2500 active elements (0 deactivated)
13:57:51 INFO    opendrift:2237: 2026-09-11 01:41:51.532773 - step 48 of 64 - 2500 active elements (0 deactivated)
13:57:51 INFO    opendrift:2237: 2026-09-11 01:56:51.532773 - step 49 of 64 - 2500 active elements (0 deactivated)
13:57:52 INFO    opendrift:2237: 2026-09-11 02:11:51.532773 - step 50 of 64 - 2500 active elements (0 deactivated)
13:57:54 INFO    opendrift:2237: 2026-09-11 02:26:51.532773 - step 51 of 64 - 2500 active elements (0 deactivated)
13:57:54 INFO    opendrift:2237: 2026-09-11 02:41:51.532773 - step 52 of 64 - 2500 active elements (0 deactivated)
13:57:55 INFO    opendrift:2237: 2026-09-11 02:56:51.532773 - step 53 of 64 - 2500 active elements (0 deactivated)
13:57:56 INFO    opendrift:2237: 2026-09-11 03:11:51.532773 - step 54 of 64 - 2500 active elements (0 deactivated)
13:57:58 INFO    opendrift:2237: 2026-09-11 03:26:51.532773 - step 55 of 64 - 2500 active elements (0 deactivated)
13:57:58 INFO    opendrift:2237: 2026-09-11 03:41:51.532773 - step 56 of 64 - 2500 active elements (0 deactivated)
13:57:59 INFO    opendrift:2237: 2026-09-11 03:56:51.532773 - step 57 of 64 - 2500 active elements (0 deactivated)
13:57:59 INFO    opendrift:2237: 2026-09-11 04:11:51.532773 - step 58 of 64 - 2500 active elements (0 deactivated)
13:58:01 INFO    opendrift:2237: 2026-09-11 04:26:51.532773 - step 59 of 64 - 2500 active elements (0 deactivated)
13:58:02 INFO    opendrift:2237: 2026-09-11 04:41:51.532773 - step 60 of 64 - 2500 active elements (0 deactivated)
13:58:02 INFO    opendrift:2237: 2026-09-11 04:56:51.532773 - step 61 of 64 - 2500 active elements (0 deactivated)
13:58:03 INFO    opendrift:2237: 2026-09-11 05:11:51.532773 - step 62 of 64 - 2500 active elements (0 deactivated)
13:58:07 INFO    opendrift:2237: 2026-09-11 05:26:51.532773 - step 63 of 64 - 2500 active elements (0 deactivated)
13:58:07 INFO    opendrift:2237: 2026-09-11 05:41:51.532773 - step 64 of 64 - 2500 active elements (0 deactivated)

<xarray.Dataset> Size: 7MB
Dimensions:                                   (trajectory: 2500, time: 33)
Coordinates:
  * trajectory                                (trajectory) int64 20kB 0 ... 2499
  * time                                      (time) datetime64[ns] 264B 2026...
Data variables: (12/22)
    status                                    (trajectory, time) float32 330kB ...
    moving                                    (trajectory, time) float32 330kB ...
    age_seconds                               (trajectory, time) float32 330kB ...
    origin_marker                             (trajectory, time) float32 330kB ...
    lon                                       (trajectory, time) float32 330kB ...
    lat                                       (trajectory, time) float32 330kB ...
    ...                                        ...
    horizontal_diffusivity                    (trajectory, time) float32 330kB ...
    sea_surface_wave_significant_height       (trajectory, time) float32 330kB ...
    sea_surface_wave_stokes_drift_x_velocity  (trajectory, time) float32 330kB ...
    sea_surface_wave_stokes_drift_y_velocity  (trajectory, time) float32 330kB ...
    sea_floor_depth_below_sea_level           (trajectory, time) float32 330kB ...
    land_binary_mask                          (trajectory, time) float32 330kB ...
Attributes: (12/121)
    Conventions:                                                           CF...
    standard_name_vocabulary:                                              CF...
    featureType:                                                           tr...
    title:                                                                 Op...
    summary:                                                               Ou...
    keywords:                                                              tr...
    ...                                                                    ...
    geospatial_lon_units:                                                  de...
    geospatial_lon_resolution:                                             point
    runtime:                                                               0:...
    geospatial_vertical_min:                                               0.0
    geospatial_vertical_max:                                               0.0
    geospatial_vertical_positive:                                          up

xarray.Dataset

• Dimensions:
  • trajectory: 2500
  • time: 33
• Coordinates: (2)
  • trajectory
    (trajectory)
    int64
    0 1 2 3 4 ... 2496 2497 2498 2499

    cf_role :

    trajectory_id

    dtype :

    <class 'numpy.int32'>

    array([   0,    1,    2, ..., 2497, 2498, 2499], shape=(2500,))

  • time
    (time)
    datetime64[ns]
    2026-09-10T13:56:51.532773 ... 2...

    standard_name :

    time

    long_name :

    time

    dtype :

    <class 'numpy.float64'>

    array(['2026-09-10T13:56:51.532773000', '2026-09-10T14:26:51.532773000',
           '2026-09-10T14:56:51.532773000', '2026-09-10T15:26:51.532773000',
           '2026-09-10T15:56:51.532773000', '2026-09-10T16:26:51.532773000',
           '2026-09-10T16:56:51.532773000', '2026-09-10T17:26:51.532773000',
           '2026-09-10T17:56:51.532773000', '2026-09-10T18:26:51.532773000',
           '2026-09-10T18:56:51.532773000', '2026-09-10T19:26:51.532773000',
           '2026-09-10T19:56:51.532773000', '2026-09-10T20:26:51.532773000',
           '2026-09-10T20:56:51.532773000', '2026-09-10T21:26:51.532773000',
           '2026-09-10T21:56:51.532773000', '2026-09-10T22:26:51.532773000',
           '2026-09-10T22:56:51.532773000', '2026-09-10T23:26:51.532773000',
           '2026-09-10T23:56:51.532773000', '2026-09-11T00:26:51.532773000',
           '2026-09-11T00:56:51.532773000', '2026-09-11T01:26:51.532773000',
           '2026-09-11T01:56:51.532773000', '2026-09-11T02:26:51.532773000',
           '2026-09-11T02:56:51.532773000', '2026-09-11T03:26:51.532773000',
           '2026-09-11T03:56:51.532773000', '2026-09-11T04:26:51.532773000',
           '2026-09-11T04:56:51.532773000', '2026-09-11T05:26:51.532773000',
           '2026-09-11T05:56:51.532773000'], dtype='datetime64[ns]')

• Data variables: (22)
  • status
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    dtype :

    <class 'numpy.int32'>

    valid_range :

    [0 0]

    flag_values :

    [0]

    flag_meanings :

    active

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • moving
    (trajectory, time)
    float32
    1.0 1.0 1.0 1.0 ... 1.0 1.0 1.0 1.0

    dtype :

    <class 'numpy.int32'>

    minval :

    1

    maxval :

    1

    array([[1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.],
           ...,
           [1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.]], shape=(2500, 33), dtype=float32)

  • age_seconds
    (trajectory, time)
    float32
    0.0 1.8e+03 ... 5.58e+04 5.76e+04

    dtype :

    <class 'numpy.float32'>

    units :

    s

    minval :

    0.0

    maxval :

    57600.0

    array([[    0.,  1800.,  3600., ..., 54000., 55800., 57600.],
           [    0.,  1800.,  3600., ..., 54000., 55800., 57600.],
           [    0.,  1800.,  3600., ..., 54000., 55800., 57600.],
           ...,
           [    0.,  1800.,  3600., ..., 54000., 55800., 57600.],
           [    0.,  1800.,  3600., ..., 54000., 55800., 57600.],
           [    0.,  1800.,  3600., ..., 54000., 55800., 57600.]],
          shape=(2500, 33), dtype=float32)

  • origin_marker
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    dtype :

    <class 'numpy.int32'>

    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

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • lon
    (trajectory, time)
    float32
    5.0 5.003 5.004 ... 8.326 8.337

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_east

    standard_name :

    longitude

    long_name :

    longitude

    axis :

    X

    minval :

    4.868629

    maxval :

    8.336709

    array([[5.       , 5.0027676, 5.004341 , ..., 5.1251583, 5.1249776,
            5.1255345],
           [5.0612245, 5.064051 , 5.0656643, ..., 5.1920147, 5.192095 ,
            5.1929326],
           [5.122449 , 5.1253176, 5.12698  , ..., 5.2588515, 5.259163 ,
            5.2602496],
           ...,
           [7.877551 , 7.882674 , 7.888007 , ..., 8.20117  , 8.211476 ,
            8.222113 ],
           [7.9387755, 7.9438953, 7.9493885, ..., 8.261916 , 8.2720585,
            8.282566 ],
           [8.       , 8.005254 , 8.011082 , ..., 8.3162775, 8.3263035,
            8.336709 ]], shape=(2500, 33), dtype=float32)

  • lat
    (trajectory, time)
    float32
    69.8 69.8 69.8 ... 70.89 70.9 70.91

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_north

    standard_name :

    latitude

    long_name :

    latitude

    axis :

    Y

    minval :

    69.79927

    maxval :

    70.90791

    array([[69.8     , 69.799545, 69.79928 , ..., 69.842735, 69.84528 ,
            69.84826 ],
           [69.8     , 69.79962 , 69.79943 , ..., 69.84618 , 69.84889 ,
            69.852036],
           [69.8     , 69.79971 , 69.79963 , ..., 69.84968 , 69.852554,
            69.85585 ],
           ...,
           [70.8     , 70.80251 , 70.8054  , ..., 70.86833 , 70.87359 ,
            70.87874 ],
           [70.8     , 70.80242 , 70.80525 , ..., 70.87956 , 70.885666,
            70.89159 ],
           [70.8     , 70.802444, 70.80535 , ..., 70.89436 , 70.901276,
            70.90791 ]], shape=(2500, 33), dtype=float32)

  • z
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    dtype :

    <class 'numpy.float32'>

    units :

    m

    standard_name :

    z

    long_name :

    vertical position

    axis :

    Z

    positive :

    up

    minval :

    0.0

    maxval :

    0.0

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • wind_drift_factor
    (trajectory, time)
    float32
    0.02 0.02 0.02 ... 0.02 0.02 0.02

    dtype :

    <class 'numpy.float32'>

    units :

    1

    description :

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

    minval :

    0.02

    maxval :

    0.02

    array([[0.02, 0.02, 0.02, ..., 0.02, 0.02, 0.02],
           [0.02, 0.02, 0.02, ..., 0.02, 0.02, 0.02],
           [0.02, 0.02, 0.02, ..., 0.02, 0.02, 0.02],
           ...,
           [0.02, 0.02, 0.02, ..., 0.02, 0.02, 0.02],
           [0.02, 0.02, 0.02, ..., 0.02, 0.02, 0.02],
           [0.02, 0.02, 0.02, ..., 0.02, 0.02, 0.02]],
          shape=(2500, 33), dtype=float32)

  • current_drift_factor
    (trajectory, time)
    float32
    1.0 1.0 1.0 1.0 ... 1.0 1.0 1.0 1.0

    dtype :

    <class 'numpy.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

    array([[1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.],
           ...,
           [1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.],
           [1., 1., 1., ..., 1., 1., 1.]], shape=(2500, 33), dtype=float32)

  • terminal_velocity
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    dtype :

    <class 'numpy.float32'>

    units :

    m/s

    description :

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

    minval :

    0.0

    maxval :

    0.0

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • x_sea_water_velocity
    (trajectory, time)
    float32
    0.06615 0.03955 ... 0.2118 0.2259

    minval :

    -0.16807416

    maxval :

    0.36366403

    array([[ 6.6150695e-02,  3.9551944e-02,  1.7491886e-02, ...,
            -6.8984390e-03,  7.1074031e-03,  1.6709473e-02],
           [ 6.7580335e-02,  4.0442955e-02,  1.8300563e-02, ...,
            -1.4456116e-03,  1.3006954e-02,  2.2794357e-02],
           [ 6.8497464e-02,  4.1405804e-02,  1.9725103e-02, ...,
             3.3834295e-03,  1.8245418e-02,  2.8186614e-02],
           ...,
           [-7.3680510e-03,  2.6546999e-05,  6.0915132e-03, ...,
             1.8593577e-01,  2.1444435e-01,  2.2793970e-01],
           [-7.4964836e-03,  3.2462527e-03,  1.2852794e-02, ...,
             1.8362533e-01,  2.1332552e-01,  2.2778492e-01],
           [-4.3733325e-03,  9.8308474e-03,  2.5546910e-02, ...,
             1.8263498e-01,  2.1179312e-01,  2.2587384e-01]],
          shape=(2500, 33), dtype=float32)

  • y_sea_water_velocity
    (trajectory, time)
    float32
    -0.0302 -0.02051 ... 0.2624 0.2531

    minval :

    -0.15124175

    maxval :

    0.279696

    array([[-0.03019701, -0.02051139, -0.00513555, ...,  0.15055403,
             0.17833927,  0.19136544],
           [-0.02604089, -0.01528983,  0.00120786, ...,  0.16103823,
             0.18832102,  0.2011368 ],
           [-0.02060088, -0.00911291,  0.00804392, ...,  0.17166556,
             0.19823742,  0.21064721],
           ...,
           [ 0.05549066,  0.07300934,  0.09167158, ...,  0.1737158 ,
             0.16753064,  0.16262804],
           [ 0.05052058,  0.07003828,  0.09037059, ...,  0.22818403,
             0.2157187 ,  0.20800456],
           [ 0.05230513,  0.07414369,  0.09737855, ...,  0.2785491 ,
             0.26235473,  0.25311613]], shape=(2500, 33), dtype=float32)

  • sea_surface_height
    (trajectory, time)
    float32
    -0.6588 -0.8112 ... -1.455 -1.475

    minval :

    -1.5036445

    maxval :

    0.2772461

    array([[-0.6588244 , -0.8112301 , -0.9515296 , ..., -1.429336  ,
            -1.4510136 , -1.4429739 ],
           [-0.6563169 , -0.8089554 , -0.9495384 , ..., -1.4288027 ,
            -1.4507533 , -1.4428076 ],
           [-0.6536546 , -0.8065479 , -0.94744724, ..., -1.4280533 ,
            -1.450243  , -1.4423728 ],
           ...,
           [-0.39077163, -0.5580996 , -0.7270723 , ..., -1.4022883 ,
            -1.4509367 , -1.4703783 ],
           [-0.38939232, -0.5569768 , -0.7263204 , ..., -1.4053997 ,
            -1.4538009 , -1.4733971 ],
           [-0.38844085, -0.5566262 , -0.72656184, ..., -1.4067705 ,
            -1.4553938 , -1.4751139 ]], shape=(2500, 33), dtype=float32)

  • x_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... -0.1187 -0.65

    minval :

    -3.5605147

    maxval :

    6.4797387

    array([[ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           [ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           [ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           ...,
           [ 5.5657015 ,  5.389705  ,  5.226654  , ...,  1.0478038 ,
             0.03076699, -0.535825  ],
           [ 5.5208826 ,  5.353079  ,  5.1876926 , ...,  0.96969295,
            -0.07006973, -0.64530253],
           [ 5.4576626 ,  5.298619  ,  5.1356645 , ...,  0.8987147 ,
            -0.11874093, -0.6499808 ]], shape=(2500, 33), dtype=float32)

  • y_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 7.627 7.708 7.664

    minval :

    0.0

    maxval :

    11.583434

    array([[0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           ...,
           [4.7193117, 4.983887 , 5.2476716, ..., 7.6453414, 7.699964 ,
            7.7044134],
           [4.6354985, 4.951169 , 5.262757 , ..., 7.610439 , 7.731739 ,
            7.739607 ],
           [4.585474 , 4.935805 , 5.277305 , ..., 7.626843 , 7.7076297,
            7.6639733]], shape=(2500, 33), dtype=float32)

  • upward_sea_water_velocity
    (trajectory, time)
    float32
    0.0 0.0 ... -2.314e-05 -8.141e-06

    minval :

    -0.0025337017

    maxval :

    0.001148953

    array([[ 0.0000000e+00,  0.0000000e+00,  0.0000000e+00, ...,
             0.0000000e+00,  0.0000000e+00,  0.0000000e+00],
           [ 0.0000000e+00,  0.0000000e+00,  0.0000000e+00, ...,
             0.0000000e+00,  0.0000000e+00,  0.0000000e+00],
           [ 0.0000000e+00,  0.0000000e+00,  0.0000000e+00, ...,
             0.0000000e+00,  0.0000000e+00,  0.0000000e+00],
           ...,
           [-8.8952962e-05, -8.9080262e-05, -8.7794302e-05, ...,
            -5.2395484e-05, -2.5423060e-05, -1.1415027e-05],
           [-8.8715577e-05, -8.5523519e-05, -8.0523518e-05, ...,
            -5.2094078e-05, -2.3141120e-05, -8.1411199e-06],
           [-9.7752505e-05, -9.5409669e-05, -9.0523521e-05, ...,
            -5.2094078e-05, -2.3141120e-05, -8.1411199e-06]],
          shape=(2500, 33), dtype=float32)

  • horizontal_diffusivity
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    minval :

    0.0

    maxval :

    0.0

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • sea_surface_wave_significant_height
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 1.451 1.462 1.455

    minval :

    0.0

    maxval :

    3.4254024

    array([[0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           ...,
           [1.309924 , 1.3256462, 1.3494569, ..., 1.4649087, 1.4585437,
            1.4672694],
           [1.2784126, 1.3079703, 1.3433756, ..., 1.4479333, 1.4707035,
            1.483821 ],
           [1.249991 , 1.2899632, 1.3339348, ..., 1.4508201, 1.4617727,
            1.4553105]], shape=(2500, 33), dtype=float32)

  • sea_surface_wave_stokes_drift_x_velocity
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    minval :

    0.0

    maxval :

    0.0

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • sea_surface_wave_stokes_drift_y_velocity
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    minval :

    0.0

    maxval :

    0.0

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

  • sea_floor_depth_below_sea_level
    (trajectory, time)
    float32
    3.238e+03 3.237e+03 ... 2.823e+03

    minval :

    2822.5818

    maxval :

    3237.6443

    array([[3237.6443, 3237.3804, 3237.232 , ..., 3223.8608, 3223.5862,
            3223.3958],
           [3231.7295, 3231.5078, 3231.3809, ..., 3219.8875, 3219.6714,
            3219.5354],
           [3226.8372, 3226.6257, 3226.5015, ..., 3216.6826, 3216.5205,
            3216.4214],
           ...,
           [2909.3315, 2908.2957, 2907.1738, ..., 2845.481 , 2842.7537,
            2841.3901],
           [2900.6636, 2899.5225, 2898.2595, ..., 2835.3926, 2832.7454,
            2831.4448],
           [2890.7188, 2889.507 , 2888.111 , ..., 2826.3552, 2823.8147,
            2822.5818]], shape=(2500, 33), dtype=float32)

  • land_binary_mask
    (trajectory, time)
    float32
    0.0 0.0 0.0 0.0 ... 0.0 0.0 0.0 0.0

    minval :

    0.0

    maxval :

    0.0

    array([[0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           ...,
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.],
           [0., 0., 0., ..., 0., 0., 0.]], shape=(2500, 33), dtype=float32)

• Attributes: (121)

  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 2026-09-10 13:56:57.412424

  date_created :

  2026-09-10T13:56:57.412433

  source :

  Output from simulation with OpenDrift

  model_url :

  https://github.com/OpenDrift/opendrift

  opendrift_class :

  OceanDrift

  opendrift_module :

  opendrift.models.oceandrift

  readers :

  odict_keys(['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be', 'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml', 'global_landmask'])

  time_coverage_start :

  2026-09-10 13:56:51.532773

  time_step_calculation :

  0:15:00

  time_step_output :

  0:30:00

  config_environment:constant:x_sea_water_velocity :

  None

  config_environment:fallback:x_sea_water_velocity :

  0

  config_environment:constant:y_sea_water_velocity :

  None

  config_environment:fallback:y_sea_water_velocity :

  0

  config_environment:constant:sea_surface_height :

  None

  config_environment:fallback:sea_surface_height :

  0

  config_environment:constant:x_wind :

  None

  config_environment:fallback:x_wind :

  0

  config_environment:constant:y_wind :

  None

  config_environment:fallback:y_wind :

  0

  config_environment:constant:upward_sea_water_velocity :

  None

  config_environment:fallback:upward_sea_water_velocity :

  0

  config_environment:constant:ocean_vertical_diffusivity :

  None

  config_environment:fallback:ocean_vertical_diffusivity :

  0

  config_environment:constant:horizontal_diffusivity :

  None

  config_environment:fallback:horizontal_diffusivity :

  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:ocean_mixed_layer_thickness :

  None

  config_environment:fallback:ocean_mixed_layer_thickness :

  50

  config_environment:constant:sea_floor_depth_below_sea_level :

  None

  config_environment:fallback:sea_floor_depth_below_sea_level :

  10000

  config_environment:constant:land_binary_mask :

  None

  config_environment:fallback:land_binary_mask :

  0.0

  config_general:use_auto_landmask :

  True

  config_drift:current_uncertainty :

  0

  config_drift:current_uncertainty_uniform :

  0

  config_drift:max_speed :

  2.0

  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

  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 :

  0.02

  config_seed:current_drift_factor :

  1

  config_seed:terminal_velocity :

  0.0

  config_drift:vertical_advection :

  True

  config_drift:vertical_advection_at_surface :

  False

  config_drift:water_column_stretching :

  False

  config_drift:vertical_advection_correction :

  False

  config_drift:vertical_mixing :

  False

  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

  opendrift_version :

  1.14.11

  seed_geojson :

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

  simulation_time :

  2026-09-10 13:56:57.419257

  reader_x_sea_water_velocity :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be', 'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml']

  reader_y_sea_water_velocity :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be', 'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml']

  reader_sea_surface_height :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be', 'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml']

  reader_x_wind :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be']

  reader_y_wind :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be']

  reader_upward_sea_water_velocity :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be']

  reader_horizontal_diffusivity :

  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_floor_depth_below_sea_level :

  ['https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be', 'https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml']

  reader_land_binary_mask :

  ['global_landmask']

  time_coverage_end :

  2026-09-11 05:56:51.532773

  time_coverage_duration :

  P0DT16H0M0S

  time_coverage_resolution :

  P0DT0H15M0S

  performance :

  -------------------- Reader performance: -------------------- https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be 0:00:34.2 total 0:00:00.0 preparing 0:00:33.7 reading 0:00:00.3 interpolation 0:00:00.0 interpolation_time 0:00:00.3 rotating vectors 0:00:00.0 masking -------------------- https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml 0:00:34.5 total 0:00:00.0 preparing 0:00:34.4 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: 1:22.5 total time 11.6 configuration 0.0 preparing main loop 0.0 moving elements to ocean 1:10.8 main loop 0.2 updating elements 0.0 cleaning up --------------------

  geospatial_bounds_crs :

  EPSG:4326

  geospatial_bounds_vertical_crs :

  EPSG:5831

  geospatial_lat_min :

  69.79927

  geospatial_lat_max :

  70.90791

  geospatial_lat_units :

  degrees_north

  geospatial_lat_resolution :

  point

  geospatial_lon_min :

  4.868629

  geospatial_lon_max :

  8.336709

  geospatial_lon_units :

  degrees_east

  geospatial_lon_resolution :

  point

  runtime :

  0:01:22.516672

  geospatial_vertical_min :

  0.0

  geospatial_vertical_max :

  0.0

  geospatial_vertical_positive :

  up

Print and plot results

print(o)
o.animation(fast=True)

===========================
--------------------
Reader performance:
--------------------
https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be
 0:00:34.2  total
 0:00:00.0  preparing
 0:00:33.7  reading
 0:00:00.3  interpolation
 0:00:00.0  interpolation_time
 0:00:00.3  rotating vectors
 0:00:00.0  masking
--------------------
https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
 0:00:34.5  total
 0:00:00.0  preparing
 0:00:34.4  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:
 1:22.5 total time
   11.6 configuration
    0.0 preparing main loop
      0.0 moving elements to ocean
 1:10.8 main loop
      0.2 updating elements
    0.0 cleaning up
--------------------
===========================
Model:  OceanDrift     (OpenDrift version 1.14.11)
        2500 active Lagrangian3DArray particles  (0 deactivated, 0 scheduled)
-------------------
Environment variables:
  -----
  sea_floor_depth_below_sea_level
  sea_surface_height
  x_sea_water_velocity
  y_sea_water_velocity
     1) https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be
     2) https://thredds.met.no/thredds/dodsC/cmems/topaz6/dataset-topaz6-arc-15min-3km-be.ncml
  -----
  upward_sea_water_velocity
  x_wind
  y_wind
     1) https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be
  -----
  land_binary_mask
     1) global_landmask
  -----
Readers not added for the following variables:
  horizontal_diffusivity
  sea_surface_wave_significant_height
  sea_surface_wave_stokes_drift_x_velocity
  sea_surface_wave_stokes_drift_y_velocity

Discarded readers:

Time:
        Start: 2026-09-10 13:56:51.532773 UTC
        Present: 2026-09-11 05:56:51.532773 UTC
        Calculation steps: 64 * 0:15:00 - total time: 16:00:00
        Output steps: 33 * 0:30:00
===========================

13:58:08 WARNING opendrift:2613: Plotting fast. This will make your plots less accurate.
13:58:09 INFO    opendrift:4823: Saving animation to /root/project/docs/source/gallery/animations/example_reader_boundary_0.gif...
13:58:25 INFO    opendrift:3241: Time to make animation: 0:00:17.047317

o.plot(fast=True)

13:58:25 WARNING opendrift:2613: Plotting fast. This will make your plots less accurate.

(<GeoAxes: title={'center': 'OpenDrift - OceanDrift\n2026-09-10 13:56 to 2026-09-11 05:56 UTC (33 steps)'}>, <Figure size 954.925x1100 with 1 Axes>)