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)

15:38:54 INFO    opendrift:569: OpenDriftSimulation initialised (version 1.14.11 / v1.14.12-32-g22db1c0)
15:38:54 INFO    opendrift.readers:67: Opening file with xr.open_dataset
15:38:58 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'X', 'y': 'Y', 'z': 'depth', 'time': 'time'}
15:38:58 INFO    opendrift.readers.basereader:175: Variable x_sea_water_velocity will be rotated from eastward_sea_water_velocity
15:38:58 INFO    opendrift.readers.basereader:175: Variable y_sea_water_velocity will be rotated from northward_sea_water_velocity
15:38:58 INFO    opendrift.readers.basereader:175: Variable x_wind will be rotated from eastward_wind
15:38:58 INFO    opendrift.readers.basereader:175: Variable y_wind will be rotated from northward_wind
15:38:58 INFO    opendrift.readers:67: Opening file with xr.open_dataset
15:39:00 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())

15:39:00 INFO    opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
15:39:06 INFO    opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
15:39:06 INFO    opendrift.models.basemodel.environment:230:    horizontal_diffusivity: 0.000000
15:39:06 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_significant_height: 0.000000
15:39:06 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_x_velocity: 0.000000
15:39:06 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_y_velocity: 0.000000
15:39:06 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)

15:39:06 INFO    opendrift:1910: Skipping environment variable ocean_vertical_diffusivity because of condition ['drift:vertical_mixing', 'is', False]
15:39:06 INFO    opendrift:1910: Skipping environment variable ocean_mixed_layer_thickness because of condition ['drift:vertical_mixing', 'is', False]
15:39:06 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']))
15:39:06 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']))
15:39:06 INFO    opendrift:1929: Storing previous values of environment variable sea_surface_height because of condition ['drift:vertical_advection', 'is', True]
15:39:06 INFO    opendrift:958: Using existing reader for land_binary_mask to move elements to ocean
15:39:06 INFO    opendrift:989: All points are in ocean
15:39:06 INFO    opendrift:2237: 2026-10-05 15:39:00.671576 - step 1 of 64 - 2500 active elements (0 deactivated)
15:39:12 INFO    opendrift:2237: 2026-10-05 15:54:00.671576 - step 2 of 64 - 2500 active elements (0 deactivated)
15:39:12 INFO    opendrift:2237: 2026-10-05 16:09:00.671576 - step 3 of 64 - 2500 active elements (0 deactivated)
15:39:14 INFO    opendrift:2237: 2026-10-05 16:24:00.671576 - step 4 of 64 - 2500 active elements (0 deactivated)
15:39:15 INFO    opendrift:2237: 2026-10-05 16:39:00.671576 - step 5 of 64 - 2500 active elements (0 deactivated)
15:39:15 INFO    opendrift:2237: 2026-10-05 16:54:00.671576 - step 6 of 64 - 2500 active elements (0 deactivated)
15:39:16 INFO    opendrift:2237: 2026-10-05 17:09:00.671576 - step 7 of 64 - 2500 active elements (0 deactivated)
15:39:18 INFO    opendrift:2237: 2026-10-05 17:24:00.671576 - step 8 of 64 - 2500 active elements (0 deactivated)
15:39:19 INFO    opendrift:2237: 2026-10-05 17:39:00.671576 - step 9 of 64 - 2500 active elements (0 deactivated)
15:39:19 INFO    opendrift:2237: 2026-10-05 17:54:00.671576 - step 10 of 64 - 2500 active elements (0 deactivated)
15:39:20 INFO    opendrift:2237: 2026-10-05 18:09:00.671576 - step 11 of 64 - 2500 active elements (0 deactivated)
15:39:23 INFO    opendrift:2237: 2026-10-05 18:24:00.671576 - step 12 of 64 - 2500 active elements (0 deactivated)
15:39:24 INFO    opendrift:2237: 2026-10-05 18:39:00.671576 - step 13 of 64 - 2500 active elements (0 deactivated)
15:39:25 INFO    opendrift:2237: 2026-10-05 18:54:00.671576 - step 14 of 64 - 2500 active elements (0 deactivated)
15:39:25 INFO    opendrift:2237: 2026-10-05 19:09:00.671576 - step 15 of 64 - 2500 active elements (0 deactivated)
15:39:28 INFO    opendrift:2237: 2026-10-05 19:24:00.671576 - step 16 of 64 - 2500 active elements (0 deactivated)
15:39:28 INFO    opendrift:2237: 2026-10-05 19:39:00.671576 - step 17 of 64 - 2500 active elements (0 deactivated)
15:39:29 INFO    opendrift:2237: 2026-10-05 19:54:00.671576 - step 18 of 64 - 2500 active elements (0 deactivated)
15:39:30 INFO    opendrift:2237: 2026-10-05 20:09:00.671576 - step 19 of 64 - 2500 active elements (0 deactivated)
15:39:33 INFO    opendrift:2237: 2026-10-05 20:24:00.671576 - step 20 of 64 - 2500 active elements (0 deactivated)
15:39:34 INFO    opendrift:2237: 2026-10-05 20:39:00.671576 - step 21 of 64 - 2500 active elements (0 deactivated)
15:39:35 INFO    opendrift:2237: 2026-10-05 20:54:00.671576 - step 22 of 64 - 2500 active elements (0 deactivated)
15:39:35 INFO    opendrift:2237: 2026-10-05 21:09:00.671576 - step 23 of 64 - 2500 active elements (0 deactivated)
15:39:38 INFO    opendrift:2237: 2026-10-05 21:24:00.671576 - step 24 of 64 - 2500 active elements (0 deactivated)
15:39:39 INFO    opendrift:2237: 2026-10-05 21:39:00.671576 - step 25 of 64 - 2500 active elements (0 deactivated)
15:39:39 INFO    opendrift:2237: 2026-10-05 21:54:00.671576 - step 26 of 64 - 2500 active elements (0 deactivated)
15:39:40 INFO    opendrift:2237: 2026-10-05 22:09:00.671576 - step 27 of 64 - 2500 active elements (0 deactivated)
15:39:42 INFO    opendrift:2237: 2026-10-05 22:24:00.671576 - step 28 of 64 - 2500 active elements (0 deactivated)
15:39:43 INFO    opendrift:2237: 2026-10-05 22:39:00.671576 - step 29 of 64 - 2500 active elements (0 deactivated)
15:39:43 INFO    opendrift:2237: 2026-10-05 22:54:00.671576 - step 30 of 64 - 2500 active elements (0 deactivated)
15:39:44 INFO    opendrift:2237: 2026-10-05 23:09:00.671576 - step 31 of 64 - 2500 active elements (0 deactivated)
15:39:46 INFO    opendrift:2237: 2026-10-05 23:24:00.671576 - step 32 of 64 - 2500 active elements (0 deactivated)
15:39:47 INFO    opendrift:2237: 2026-10-05 23:39:00.671576 - step 33 of 64 - 2500 active elements (0 deactivated)
15:39:48 INFO    opendrift:2237: 2026-10-05 23:54:00.671576 - step 34 of 64 - 2500 active elements (0 deactivated)
15:39:48 INFO    opendrift:2237: 2026-10-06 00:09:00.671576 - step 35 of 64 - 2500 active elements (0 deactivated)
15:39:50 INFO    opendrift:2237: 2026-10-06 00:24:00.671576 - step 36 of 64 - 2500 active elements (0 deactivated)
15:39:51 INFO    opendrift:2237: 2026-10-06 00:39:00.671576 - step 37 of 64 - 2500 active elements (0 deactivated)
15:39:51 INFO    opendrift:2237: 2026-10-06 00:54:00.671576 - step 38 of 64 - 2500 active elements (0 deactivated)
15:39:52 INFO    opendrift:2237: 2026-10-06 01:09:00.671576 - step 39 of 64 - 2500 active elements (0 deactivated)
15:39:56 INFO    opendrift:2237: 2026-10-06 01:24:00.671576 - step 40 of 64 - 2500 active elements (0 deactivated)
15:39:57 INFO    opendrift:2237: 2026-10-06 01:39:00.671576 - step 41 of 64 - 2500 active elements (0 deactivated)
15:39:57 INFO    opendrift:2237: 2026-10-06 01:54:00.671576 - step 42 of 64 - 2500 active elements (0 deactivated)
15:39:58 INFO    opendrift:2237: 2026-10-06 02:09:00.671576 - step 43 of 64 - 2500 active elements (0 deactivated)
15:40:02 INFO    opendrift:2237: 2026-10-06 02:24:00.671576 - step 44 of 64 - 2500 active elements (0 deactivated)
15:40:02 INFO    opendrift:2237: 2026-10-06 02:39:00.671576 - step 45 of 64 - 2500 active elements (0 deactivated)
15:40:03 INFO    opendrift:2237: 2026-10-06 02:54:00.671576 - step 46 of 64 - 2500 active elements (0 deactivated)
15:40:03 INFO    opendrift:2237: 2026-10-06 03:09:00.671576 - step 47 of 64 - 2500 active elements (0 deactivated)
15:40:10 INFO    opendrift:2237: 2026-10-06 03:24:00.671576 - step 48 of 64 - 2500 active elements (0 deactivated)
15:40:11 INFO    opendrift:2237: 2026-10-06 03:39:00.671576 - step 49 of 64 - 2500 active elements (0 deactivated)
15:40:12 INFO    opendrift:2237: 2026-10-06 03:54:00.671576 - step 50 of 64 - 2500 active elements (0 deactivated)
15:40:12 INFO    opendrift:2237: 2026-10-06 04:09:00.671576 - step 51 of 64 - 2500 active elements (0 deactivated)
15:40:15 INFO    opendrift:2237: 2026-10-06 04:24:00.671576 - step 52 of 64 - 2500 active elements (0 deactivated)
15:40:16 INFO    opendrift:2237: 2026-10-06 04:39:00.671576 - step 53 of 64 - 2500 active elements (0 deactivated)
15:40:17 INFO    opendrift:2237: 2026-10-06 04:54:00.671576 - step 54 of 64 - 2500 active elements (0 deactivated)
15:40:18 INFO    opendrift:2237: 2026-10-06 05:09:00.671576 - step 55 of 64 - 2500 active elements (0 deactivated)
15:40:21 INFO    opendrift:2237: 2026-10-06 05:24:00.671576 - step 56 of 64 - 2500 active elements (0 deactivated)
15:40:21 INFO    opendrift:2237: 2026-10-06 05:39:00.671576 - step 57 of 64 - 2500 active elements (0 deactivated)
15:40:22 INFO    opendrift:2237: 2026-10-06 05:54:00.671576 - step 58 of 64 - 2500 active elements (0 deactivated)
15:40:22 INFO    opendrift:2237: 2026-10-06 06:09:00.671576 - step 59 of 64 - 2500 active elements (0 deactivated)
15:40:25 INFO    opendrift:2237: 2026-10-06 06:24:00.671576 - step 60 of 64 - 2500 active elements (0 deactivated)
15:40:26 INFO    opendrift:2237: 2026-10-06 06:39:00.671576 - step 61 of 64 - 2500 active elements (0 deactivated)
15:40:27 INFO    opendrift:2237: 2026-10-06 06:54:00.671576 - step 62 of 64 - 2500 active elements (0 deactivated)
15:40:27 INFO    opendrift:2237: 2026-10-06 07:09:00.671576 - step 63 of 64 - 2500 active elements (0 deactivated)
15:40:30 INFO    opendrift:2237: 2026-10-06 07:24:00.671576 - 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]
    2026-10-05T15:39:00.671576 ... 2...

    standard_name :

    time

    long_name :

    time

    dtype :

    <class 'numpy.float64'>

    array(['2026-10-05T15:39:00.671576000', '2026-10-05T16:09:00.671576000',
           '2026-10-05T16:39:00.671576000', '2026-10-05T17:09:00.671576000',
           '2026-10-05T17:39:00.671576000', '2026-10-05T18:09:00.671576000',
           '2026-10-05T18:39:00.671576000', '2026-10-05T19:09:00.671576000',
           '2026-10-05T19:39:00.671576000', '2026-10-05T20:09:00.671576000',
           '2026-10-05T20:39:00.671576000', '2026-10-05T21:09:00.671576000',
           '2026-10-05T21:39:00.671576000', '2026-10-05T22:09:00.671576000',
           '2026-10-05T22:39:00.671576000', '2026-10-05T23:09:00.671576000',
           '2026-10-05T23:39:00.671576000', '2026-10-06T00:09:00.671576000',
           '2026-10-06T00:39:00.671576000', '2026-10-06T01:09:00.671576000',
           '2026-10-06T01:39:00.671576000', '2026-10-06T02:09:00.671576000',
           '2026-10-06T02:39:00.671576000', '2026-10-06T03:09:00.671576000',
           '2026-10-06T03:39:00.671576000', '2026-10-06T04:09:00.671576000',
           '2026-10-06T04:39:00.671576000', '2026-10-06T05:09:00.671576000',
           '2026-10-06T05:39:00.671576000', '2026-10-06T06:09:00.671576000',
           '2026-10-06T06:39:00.671576000', '2026-10-06T07:09:00.671576000',
           '2026-10-06T07:39:00.671576000'], 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 5.007 ... 7.968 7.967

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_east

    standard_name :

    longitude

    long_name :

    longitude

    axis :

    X

    minval :

    4.757817

    maxval :

    8.037188

    array([[5.       , 5.003309 , 5.0074735, ..., 5.003958 , 5.0076284,
            5.0117307],
           [5.0612245, 5.0641875, 5.0680323, ..., 5.0584726, 5.061844 ,
            5.065654 ],
           [5.122449 , 5.1251507, 5.1287446, ..., 5.1138315, 5.1169086,
            5.1204333],
           ...,
           [7.877551 , 7.876033 , 7.8740644, ..., 7.838181 , 7.837381 ,
            7.836099 ],
           [7.9387755, 7.9377675, 7.9363046, ..., 7.9055433, 7.9046984,
            7.9035482],
           [8.       , 7.9990277, 7.997516 , ..., 7.968812 , 7.9680605,
            7.967099 ]], shape=(2500, 33), dtype=float32)

  • lat
    (trajectory, time)
    float32
    69.8 69.8 69.8 ... 70.67 70.67

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_north

    standard_name :

    latitude

    long_name :

    latitude

    axis :

    Y

    minval :

    69.635574

    maxval :

    70.80092

    array([[69.8     , 69.80156 , 69.80298 , ..., 69.77325 , 69.77307 ,
            69.772644],
           [69.8     , 69.801506, 69.80287 , ..., 69.771484, 69.77126 ,
            69.770805],
           [69.8     , 69.801445, 69.80276 , ..., 69.76992 , 69.76967 ,
            69.76919 ],
           ...,
           [70.8     , 70.79819 , 70.79598 , ..., 70.674286, 70.66832 ,
            70.66288 ],
           [70.8     , 70.79821 , 70.79604 , ..., 70.675896, 70.66988 ,
            70.66438 ],
           [70.8     , 70.79818 , 70.796005, ..., 70.67804 , 70.67199 ,
            70.66643 ]], 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
    0.06595 0.08499 ... -0.1057 -0.1076

    minval :

    -0.30241454

    maxval :

    0.20550762

    array([[ 0.06595445,  0.08498608,  0.1008083 , ...,  0.07573815,
             0.08632611,  0.08962002],
           [ 0.05842498,  0.07798859,  0.09435233, ...,  0.06929801,
             0.08002356,  0.08341659],
           [ 0.05277952,  0.07255672,  0.08915951, ...,  0.06296746,
             0.07384325,  0.07736286],
           ...,
           [ 0.05899732,  0.05282643,  0.04025779, ..., -0.09829757,
            -0.1099298 , -0.11039493],
           [ 0.07288429,  0.06560316,  0.0504718 , ..., -0.09878029,
            -0.10888913, -0.10962389],
           [ 0.08559704,  0.07468384,  0.05584947, ..., -0.09690127,
            -0.10569778, -0.10764103]], shape=(2500, 33), dtype=float32)

  • y_sea_water_velocity
    (trajectory, time)
    float32
    0.09795 0.09086 ... -0.08846

    minval :

    -0.33565304

    maxval :

    0.21839951

    array([[ 0.09795007,  0.09086002,  0.0770838 , ..., -0.00752897,
            -0.02224427, -0.03053876],
           [ 0.09427881,  0.08765316,  0.07411847, ..., -0.01005095,
            -0.02441693, -0.0325413 ],
           [ 0.09059478,  0.08433298,  0.07103415, ..., -0.01233727,
            -0.02620053, -0.0340724 ],
           ...,
           [-0.01807026, -0.03219339, -0.04274454, ..., -0.12208057,
            -0.09554064, -0.08190645],
           [-0.01455136, -0.03080767, -0.04180436, ..., -0.12498924,
            -0.09787139, -0.08527246],
           [-0.01246793, -0.03119309, -0.04160064, ..., -0.1263431 ,
            -0.10054806, -0.08846082]], shape=(2500, 33), dtype=float32)

  • sea_surface_height
    (trajectory, time)
    float32
    -0.2167 -0.132 ... -0.1796 -0.1606

    minval :

    -1.0956273

    maxval :

    0.15934709

    array([[-0.21674812, -0.13202927, -0.05160721, ..., -0.18027729,
            -0.13525668, -0.11994843],
           [-0.21483457, -0.1299645 , -0.04936378, ..., -0.17802693,
            -0.1329129 , -0.11755994],
           [-0.21302842, -0.12798856, -0.04719634, ..., -0.17573288,
            -0.13052757, -0.11513303],
           ...,
           [-0.50977856, -0.42111483, -0.33285427, ..., -0.25188   ,
            -0.18296364, -0.16432357],
           [-0.5097087 , -0.42078945, -0.3321858 , ..., -0.24999067,
            -0.18136321, -0.16246015],
           [-0.5094676 , -0.42029902, -0.33121765, ..., -0.24788919,
            -0.17962734, -0.16063292]], shape=(2500, 33), dtype=float32)

  • x_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 4.193 4.302 4.392

    minval :

    -6.7278156

    maxval :

    5.393677

    array([[ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           [ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           [ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           ...,
           [-4.497776 , -4.4398246, -4.660674 , ...,  4.2833767,  4.25331  ,
             4.131506 ],
           [-4.6509924, -4.5739794, -4.6232777, ...,  4.232283 ,  4.278676 ,
             4.2856584],
           [-5.1145477, -5.150097 , -4.727596 , ...,  4.1930065,  4.3024235,
             4.3920116]], shape=(2500, 33), dtype=float32)

  • y_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... -12.95 -12.49 -12.5

    minval :

    -14.811021

    maxval :

    3.3198109

    array([[  0.       ,   0.       ,   0.       , ...,   0.       ,
              0.       ,   0.       ],
           [  0.       ,   0.       ,   0.       , ...,   0.       ,
              0.       ,   0.       ],
           [  0.       ,   0.       ,   0.       , ...,   0.       ,
              0.       ,   0.       ],
           ...,
           [ -4.13154  ,  -5.170348 ,  -4.869927 , ..., -12.871692 ,
            -12.421616 , -12.424667 ],
           [ -4.2003126,  -5.160157 ,  -4.607344 , ..., -12.904407 ,
            -12.44611  , -12.464502 ],
           [ -4.3319087,  -5.248872 ,  -4.4196978, ..., -12.950066 ,
            -12.486939 , -12.495181 ]], shape=(2500, 33), dtype=float32)

  • upward_sea_water_velocity
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 2.7e-05 2.2e-05

    minval :

    -0.0059111305

    maxval :

    0.0053267307

    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],
           ...,
           [4.6501864e-05, 4.8498132e-05, 4.3498134e-05, ..., 4.0494404e-05,
            2.6996267e-05, 2.1996268e-05],
           [4.6501864e-05, 4.8498132e-05, 4.3498134e-05, ..., 3.6996269e-05,
            2.6996267e-05, 2.1996268e-05],
           [4.9999999e-05, 4.9999999e-05, 4.9999999e-05, ..., 3.6996269e-05,
            2.6996267e-05, 2.1996268e-05]], 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 ... 4.558 4.291 4.315

    minval :

    0.0

    maxval :

    5.567584

    array([[0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           [0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           [0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           ...,
           [0.91757035, 1.1425358 , 1.1177766 , ..., 4.527083  , 4.2407246 ,
            4.2174654 ],
           [0.9661492 , 1.1696932 , 1.048017  , ..., 4.5371237 , 4.261033  ,
            4.2737746 ],
           [1.1051311 , 1.3302243 , 1.0303437 , ..., 4.558023  , 4.2910886 ,
            4.315315  ]], 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 ... 2.894e+03

    minval :

    2890.0486

    maxval :

    3238.7603

    array([[3237.6445, 3237.222 , 3236.7168, ..., 3238.0527, 3237.657 ,
            3237.442 ],
           [3231.7295, 3231.4204, 3231.04  , ..., 3232.6152, 3232.3013,
            3232.1282],
           [3226.8374, 3226.5908, 3226.2778, ..., 3227.684 , 3227.4155,
            3227.2656],
           ...,
           [2909.3315, 2909.7932, 2910.3733, ..., 2912.5793, 2911.1777,
            2910.6216],
           [2900.6636, 2901.0745, 2901.5935, ..., 2903.0173, 2902.3887,
            2902.1626],
           [2890.7188, 2891.1328, 2891.6772, ..., 2894.8044, 2894.4973,
            2894.4016]], 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 2026-10-05 15:39:06.432691

  date_created :

  2026-10-05T15:39:06.432702

  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 :

  2026-10-05 15:39:00.671576

  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 :

  2026-10-05 15:39:06.440980

  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 :

  2026-10-06 07:39:00.671576

  time_coverage_duration :

  P0DT16H0M0S

  time_coverage_resolution :

  P0DT0H15M0S

  performance :

  -------------------- Reader performance: -------------------- https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be 0:00:44.2 total 0:00:00.0 preparing 0:00:43.8 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 0:00:37.7 total 0:00:00.0 preparing 0:00:37.6 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: 1:35.9 total time 11.7 configuration 0.0 preparing main loop 0.0 moving elements to ocean 1:24.2 main loop 0.2 updating elements 0.0 cleaning up --------------------

  geospatial_bounds_crs :

  EPSG:4326

  geospatial_bounds_vertical_crs :

  EPSG:5831

  geospatial_lat_min :

  69.635574

  geospatial_lat_max :

  70.80092

  geospatial_lat_units :

  degrees_north

  geospatial_lat_resolution :

  point

  geospatial_lon_min :

  4.757817

  geospatial_lon_max :

  8.037188

  geospatial_lon_units :

  degrees_east

  geospatial_lon_resolution :

  point

  runtime :

  0:01:35.995761

  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
 0:00:44.2  total
 0:00:00.0  preparing
 0:00:43.8  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
 0:00:37.7  total
 0:00:00.0  preparing
 0:00:37.6  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:
 1:35.9 total time
   11.7 configuration
    0.0 preparing main loop
      0.0 moving elements to ocean
 1:24.2 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: 2026-10-05 15:39:00.671576 UTC
        Present: 2026-10-06 07:39:00.671576 UTC
        Calculation steps: 64 * 0:15:00 - total time: 16:00:00
        Output steps: 33 * 0:30:00
===========================

15:40:30 WARNING opendrift:2613: Plotting fast. This will make your plots less accurate.
15:40:32 INFO    opendrift:4823: Saving animation to /root/project/docs/source/gallery/animations/example_reader_boundary_0.gif...
15:40:47 INFO    opendrift:3241: Time to make animation: 0:00:17.068528

o.plot(fast=True)

15:40:47 WARNING opendrift:2613: Plotting fast. This will make your plots less accurate.

(<GeoAxes: title={'center': 'OpenDrift - OceanDrift\n2026-10-05 15:39 to 2026-10-06 07:39 UTC (33 steps)'}>, <Figure size 908.898x1100 with 1 Axes>)