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)

16:06:24 INFO    opendrift:569: OpenDriftSimulation initialised (version 1.14.10 / v1.14.10-34-gf7a892a)
16:06:24 INFO    opendrift.readers:67: Opening file with xr.open_dataset
16:06:25 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'X', 'y': 'Y', 'z': 'depth', 'time': 'time'}
16:06:25 INFO    opendrift.readers.basereader:175: Variable x_sea_water_velocity will be rotated from eastward_sea_water_velocity
16:06:25 INFO    opendrift.readers.basereader:175: Variable y_sea_water_velocity will be rotated from northward_sea_water_velocity
16:06:25 INFO    opendrift.readers.basereader:175: Variable x_wind will be rotated from eastward_wind
16:06:25 INFO    opendrift.readers.basereader:175: Variable y_wind will be rotated from northward_wind
16:06:25 INFO    opendrift.readers:67: Opening file with xr.open_dataset
16:06:29 INFO    opendrift.readers.reader_netCDF_CF_generic:340: Detected dimensions: {'x': 'x', 'y': 'y', 'z': 'depth', '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())

16:06:29 INFO    opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
16:06:35 INFO    opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
16:06:35 INFO    opendrift.models.basemodel.environment:230:    horizontal_diffusivity: 0.000000
16:06:35 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_significant_height: 0.000000
16:06:35 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_x_velocity: 0.000000
16:06:35 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_y_velocity: 0.000000
16:06:35 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)

16:06:35 INFO    opendrift:1903: Skipping environment variable ocean_vertical_diffusivity because of condition ['drift:vertical_mixing', 'is', False]
16:06:35 INFO    opendrift:1903: Skipping environment variable ocean_mixed_layer_thickness because of condition ['drift:vertical_mixing', 'is', False]
16:06:35 INFO    opendrift:1914: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
16:06:35 INFO    opendrift:1914: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
16:06:35 INFO    opendrift:1922: Storing previous values of environment variable sea_surface_height because of condition ['drift:vertical_advection', 'is', True]
16:06:35 INFO    opendrift:955: Using existing reader for land_binary_mask to move elements to ocean
16:06:35 INFO    opendrift:986: All points are in ocean
16:06:35 INFO    opendrift:2213: 2026-08-21 16:06:29.353264 - step 1 of 64 - 2500 active elements (0 deactivated)
16:06:38 INFO    opendrift:2213: 2026-08-21 16:21:29.353264 - step 2 of 64 - 2500 active elements (0 deactivated)
16:06:39 INFO    opendrift:2213: 2026-08-21 16:36:29.353264 - step 3 of 64 - 2500 active elements (0 deactivated)
16:06:40 INFO    opendrift:2213: 2026-08-21 16:51:29.353264 - step 4 of 64 - 2500 active elements (0 deactivated)
16:06:40 INFO    opendrift:2213: 2026-08-21 17:06:29.353264 - step 5 of 64 - 2500 active elements (0 deactivated)
16:06:42 INFO    opendrift:2213: 2026-08-21 17:21:29.353264 - step 6 of 64 - 2500 active elements (0 deactivated)
16:06:43 INFO    opendrift:2213: 2026-08-21 17:36:29.353264 - step 7 of 64 - 2500 active elements (0 deactivated)
16:06:43 INFO    opendrift:2213: 2026-08-21 17:51:29.353264 - step 8 of 64 - 2500 active elements (0 deactivated)
16:06:44 INFO    opendrift:2213: 2026-08-21 18:06:29.353264 - step 9 of 64 - 2500 active elements (0 deactivated)
16:06:46 INFO    opendrift:2213: 2026-08-21 18:21:29.353264 - step 10 of 64 - 2500 active elements (0 deactivated)
16:06:46 INFO    opendrift:2213: 2026-08-21 18:36:29.353264 - step 11 of 64 - 2500 active elements (0 deactivated)
16:06:47 INFO    opendrift:2213: 2026-08-21 18:51:29.353264 - step 12 of 64 - 2500 active elements (0 deactivated)
16:06:48 INFO    opendrift:2213: 2026-08-21 19:06:29.353264 - step 13 of 64 - 2500 active elements (0 deactivated)
16:06:50 INFO    opendrift:2213: 2026-08-21 19:21:29.353264 - step 14 of 64 - 2500 active elements (0 deactivated)
16:06:50 INFO    opendrift:2213: 2026-08-21 19:36:29.353264 - step 15 of 64 - 2500 active elements (0 deactivated)
16:06:51 INFO    opendrift:2213: 2026-08-21 19:51:29.353264 - step 16 of 64 - 2500 active elements (0 deactivated)
16:06:51 INFO    opendrift:2213: 2026-08-21 20:06:29.353264 - step 17 of 64 - 2500 active elements (0 deactivated)
16:06:53 INFO    opendrift:2213: 2026-08-21 20:21:29.353264 - step 18 of 64 - 2500 active elements (0 deactivated)
16:06:54 INFO    opendrift:2213: 2026-08-21 20:36:29.353264 - step 19 of 64 - 2500 active elements (0 deactivated)
16:06:54 INFO    opendrift:2213: 2026-08-21 20:51:29.353264 - step 20 of 64 - 2500 active elements (0 deactivated)
16:06:55 INFO    opendrift:2213: 2026-08-21 21:06:29.353264 - step 21 of 64 - 2500 active elements (0 deactivated)
16:06:57 INFO    opendrift:2213: 2026-08-21 21:21:29.353264 - step 22 of 64 - 2500 active elements (0 deactivated)
16:06:57 INFO    opendrift:2213: 2026-08-21 21:36:29.353264 - step 23 of 64 - 2500 active elements (0 deactivated)
16:06:58 INFO    opendrift:2213: 2026-08-21 21:51:29.353264 - step 24 of 64 - 2500 active elements (0 deactivated)
16:06:59 INFO    opendrift:2213: 2026-08-21 22:06:29.353264 - step 25 of 64 - 2500 active elements (0 deactivated)
16:07:01 INFO    opendrift:2213: 2026-08-21 22:21:29.353264 - step 26 of 64 - 2500 active elements (0 deactivated)
16:07:01 INFO    opendrift:2213: 2026-08-21 22:36:29.353264 - step 27 of 64 - 2500 active elements (0 deactivated)
16:07:02 INFO    opendrift:2213: 2026-08-21 22:51:29.353264 - step 28 of 64 - 2500 active elements (0 deactivated)
16:07:02 INFO    opendrift:2213: 2026-08-21 23:06:29.353264 - step 29 of 64 - 2500 active elements (0 deactivated)
16:07:05 INFO    opendrift:2213: 2026-08-21 23:21:29.353264 - step 30 of 64 - 2500 active elements (0 deactivated)
16:07:05 INFO    opendrift:2213: 2026-08-21 23:36:29.353264 - step 31 of 64 - 2500 active elements (0 deactivated)
16:07:06 INFO    opendrift:2213: 2026-08-21 23:51:29.353264 - step 32 of 64 - 2500 active elements (0 deactivated)
16:07:06 INFO    opendrift:2213: 2026-08-22 00:06:29.353264 - step 33 of 64 - 2500 active elements (0 deactivated)
16:07:08 INFO    opendrift:2213: 2026-08-22 00:21:29.353264 - step 34 of 64 - 2500 active elements (0 deactivated)
16:07:09 INFO    opendrift:2213: 2026-08-22 00:36:29.353264 - step 35 of 64 - 2500 active elements (0 deactivated)
16:07:09 INFO    opendrift:2213: 2026-08-22 00:51:29.353264 - step 36 of 64 - 2500 active elements (0 deactivated)
16:07:10 INFO    opendrift:2213: 2026-08-22 01:06:29.353264 - step 37 of 64 - 2500 active elements (0 deactivated)
16:07:12 INFO    opendrift:2213: 2026-08-22 01:21:29.353264 - step 38 of 64 - 2500 active elements (0 deactivated)
16:07:13 INFO    opendrift:2213: 2026-08-22 01:36:29.353264 - step 39 of 64 - 2500 active elements (0 deactivated)
16:07:13 INFO    opendrift:2213: 2026-08-22 01:51:29.353264 - step 40 of 64 - 2500 active elements (0 deactivated)
16:07:14 INFO    opendrift:2213: 2026-08-22 02:06:29.353264 - step 41 of 64 - 2500 active elements (0 deactivated)
16:07:16 INFO    opendrift:2213: 2026-08-22 02:21:29.353264 - step 42 of 64 - 2500 active elements (0 deactivated)
16:07:16 INFO    opendrift:2213: 2026-08-22 02:36:29.353264 - step 43 of 64 - 2500 active elements (0 deactivated)
16:07:17 INFO    opendrift:2213: 2026-08-22 02:51:29.353264 - step 44 of 64 - 2500 active elements (0 deactivated)
16:07:17 INFO    opendrift:2213: 2026-08-22 03:06:29.353264 - step 45 of 64 - 2500 active elements (0 deactivated)
16:07:19 INFO    opendrift:2213: 2026-08-22 03:21:29.353264 - step 46 of 64 - 2500 active elements (0 deactivated)
16:07:20 INFO    opendrift:2213: 2026-08-22 03:36:29.353264 - step 47 of 64 - 2500 active elements (0 deactivated)
16:07:20 INFO    opendrift:2213: 2026-08-22 03:51:29.353264 - step 48 of 64 - 2500 active elements (0 deactivated)
16:07:21 INFO    opendrift:2213: 2026-08-22 04:06:29.353264 - step 49 of 64 - 2500 active elements (0 deactivated)
16:07:24 INFO    opendrift:2213: 2026-08-22 04:21:29.353264 - step 50 of 64 - 2500 active elements (0 deactivated)
16:07:24 INFO    opendrift:2213: 2026-08-22 04:36:29.353264 - step 51 of 64 - 2500 active elements (0 deactivated)
16:07:25 INFO    opendrift:2213: 2026-08-22 04:51:29.353264 - step 52 of 64 - 2500 active elements (0 deactivated)
16:07:25 INFO    opendrift:2213: 2026-08-22 05:06:29.353264 - step 53 of 64 - 2500 active elements (0 deactivated)
16:07:27 INFO    opendrift:2213: 2026-08-22 05:21:29.353264 - step 54 of 64 - 2500 active elements (0 deactivated)
16:07:28 INFO    opendrift:2213: 2026-08-22 05:36:29.353264 - step 55 of 64 - 2500 active elements (0 deactivated)
16:07:28 INFO    opendrift:2213: 2026-08-22 05:51:29.353264 - step 56 of 64 - 2500 active elements (0 deactivated)
16:07:29 INFO    opendrift:2213: 2026-08-22 06:06:29.353264 - step 57 of 64 - 2500 active elements (0 deactivated)
16:07:31 INFO    opendrift:2213: 2026-08-22 06:21:29.353264 - step 58 of 64 - 2500 active elements (0 deactivated)
16:07:31 INFO    opendrift:2213: 2026-08-22 06:36:29.353264 - step 59 of 64 - 2500 active elements (0 deactivated)
16:07:32 INFO    opendrift:2213: 2026-08-22 06:51:29.353264 - step 60 of 64 - 2500 active elements (0 deactivated)
16:07:32 INFO    opendrift:2213: 2026-08-22 07:06:29.353264 - step 61 of 64 - 2500 active elements (0 deactivated)
16:07:34 INFO    opendrift:2213: 2026-08-22 07:21:29.353264 - step 62 of 64 - 2500 active elements (0 deactivated)
16:07:35 INFO    opendrift:2213: 2026-08-22 07:36:29.353264 - step 63 of 64 - 2500 active elements (0 deactivated)
16:07:36 INFO    opendrift:2213: 2026-08-22 07:51:29.353264 - 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]
    2026-08-21T16:06:29.353264 ... 2...

    standard_name :

    time

    long_name :

    time

    dtype :

    <class 'numpy.float64'>

    array(['2026-08-21T16:06:29.353264000', '2026-08-21T16:36:29.353264000',
           '2026-08-21T17:06:29.353264000', '2026-08-21T17:36:29.353264000',
           '2026-08-21T18:06:29.353264000', '2026-08-21T18:36:29.353264000',
           '2026-08-21T19:06:29.353264000', '2026-08-21T19:36:29.353264000',
           '2026-08-21T20:06:29.353264000', '2026-08-21T20:36:29.353264000',
           '2026-08-21T21:06:29.353264000', '2026-08-21T21:36:29.353264000',
           '2026-08-21T22:06:29.353264000', '2026-08-21T22:36:29.353264000',
           '2026-08-21T23:06:29.353264000', '2026-08-21T23:36:29.353264000',
           '2026-08-22T00:06:29.353264000', '2026-08-22T00:36:29.353264000',
           '2026-08-22T01:06:29.353264000', '2026-08-22T01:36:29.353264000',
           '2026-08-22T02:06:29.353264000', '2026-08-22T02:36:29.353264000',
           '2026-08-22T03:06:29.353264000', '2026-08-22T03:36:29.353264000',
           '2026-08-22T04:06:29.353264000', '2026-08-22T04:36:29.353264000',
           '2026-08-22T05:06:29.353264000', '2026-08-22T05:36:29.353264000',
           '2026-08-22T06:06:29.353264000', '2026-08-22T06:36:29.353264000',
           '2026-08-22T07:06:29.353264000', '2026-08-22T07:36:29.353264000',
           '2026-08-22T08:06:29.353264000'], 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 4.999 4.998 ... 7.936 7.932

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_east

    standard_name :

    longitude

    long_name :

    longitude

    axis :

    X

    minval :

    4.8424144

    maxval :

    8.0

    array([[5.       , 4.999003 , 4.9984226, ..., 4.921262 , 4.921169 ,
            4.9203224],
           [5.0612245, 5.0597835, 5.0586796, ..., 4.9806657, 4.9803133,
            4.97932  ],
           [5.122449 , 5.1205935, 5.118995 , ..., 5.038731 , 5.03804  ,
            5.036816 ],
           ...,
           [7.877551 , 7.87507  , 7.872215 , ..., 7.8563657, 7.8551884,
            7.85404  ],
           [7.9387755, 7.9361725, 7.933129 , ..., 7.902095 , 7.8998785,
            7.897814 ],
           [8.       , 7.99701  , 7.993439 , ..., 7.938895 , 7.935516 ,
            7.9324613]], shape=(2500, 33), dtype=float32)

  • lat
    (trajectory, time)
    float32
    69.8 69.8 69.8 ... 70.72 70.72

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_north

    standard_name :

    latitude

    long_name :

    latitude

    axis :

    Y

    minval :

    69.7008

    maxval :

    70.83152

    array([[69.8     , 69.80021 , 69.80016 , ..., 69.78788 , 69.78656 ,
            69.78508 ],
           [69.8     , 69.80001 , 69.799805, ..., 69.78544 , 69.78415 ,
            69.78272 ],
           [69.8     , 69.79996 , 69.799736, ..., 69.78647 , 69.785324,
            69.78406 ],
           ...,
           [70.8     , 70.796844, 70.793846, ..., 70.743645, 70.74215 ,
            70.741   ],
           [70.8     , 70.796646, 70.79345 , ..., 70.73613 , 70.73425 ,
            70.73271 ],
           [70.8     , 70.796165, 70.79252 , ..., 70.72203 , 70.719864,
            70.718056]], 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
    -0.02425 -0.01397 ... -0.07335

    minval :

    -0.24715348

    maxval :

    0.2060404

    array([[-0.02425183, -0.01397324, -0.00907245, ...,  0.0016237 ,
            -0.01371612, -0.02255734],
           [-0.03324491, -0.0248475 , -0.02120028, ..., -0.00445438,
            -0.01764985, -0.02492929],
           [-0.04161611, -0.03508379, -0.03276955, ..., -0.01224977,
            -0.02321639, -0.02925104],
           ...,
           [ 0.00055881, -0.01158256, -0.02344191, ..., -0.03676823,
            -0.03727065, -0.03752681],
           [-0.00036468, -0.01434045, -0.0281151 , ..., -0.05589674,
            -0.05486645, -0.05431358],
           [-0.00629502, -0.02328169, -0.03937079, ..., -0.07926074,
            -0.0753828 , -0.07334685]], shape=(2500, 33), dtype=float32)

  • y_sea_water_velocity
    (trajectory, time)
    float32
    0.01597 0.001481 ... -0.02951

    minval :

    -0.30837813

    maxval :

    0.268884

    array([[ 0.01596545,  0.00148051, -0.01606177, ..., -0.07883091,
            -0.08999185, -0.09361902],
           [ 0.00321964, -0.0089489 , -0.02365174, ..., -0.0774607 ,
            -0.08716789, -0.08982205],
           [-0.00057825, -0.01082086, -0.0230049 , ..., -0.06868894,
            -0.0770081 , -0.07921366],
           ...,
           [-0.06527433, -0.06094731, -0.05469168, ..., -0.01844452,
            -0.00137434,  0.00724102],
           [-0.07737815, -0.07264151, -0.06585983, ..., -0.04116945,
            -0.02382252, -0.01516668],
           [-0.10670558, -0.10072928, -0.09335414, ..., -0.05764398,
            -0.03893026, -0.0295138 ]], shape=(2500, 33), dtype=float32)

  • sea_surface_height
    (trajectory, time)
    float32
    -0.4205 -0.3777 ... -0.387 -0.3966

    minval :

    -0.88477594

    maxval :

    -0.25850368

    array([[-0.42054227, -0.3777076 , -0.3503244 , ..., -0.5016713 ,
            -0.5269969 , -0.54364514],
           [-0.42056787, -0.377685  , -0.35024822, ..., -0.50152797,
            -0.52684295, -0.5435003 ],
           [-0.4206149 , -0.3776729 , -0.35016605, ..., -0.50142497,
            -0.52670985, -0.54336405],
           ...,
           [-0.42970696, -0.38729882, -0.35056573, ..., -0.3681223 ,
            -0.38714457, -0.3966446 ],
           [-0.42899948, -0.38681838, -0.34992748, ..., -0.36800689,
            -0.38677174, -0.39618734],
           [-0.42928448, -0.38630697, -0.34943092, ..., -0.36810476,
            -0.3870368 , -0.3965719 ]], shape=(2500, 33), dtype=float32)

  • x_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 0.5556 0.6239

    minval :

    -3.146311

    maxval :

    1.2381936

    array([[ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           [ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           [ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           ...,
           [-2.4629755 , -2.2387514 , -2.0561416 , ...,  0.6267877 ,
             0.6815454 ,  0.7089171 ],
           [-2.5211158 , -2.2770104 , -2.0817516 , ...,  0.48905772,
             0.59101343,  0.64249307],
           [-2.5861053 , -2.3368084 , -2.1374865 , ...,  0.42173475,
             0.5555617 ,  0.6238719 ]], shape=(2500, 33), dtype=float32)

  • y_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... -4.1 -3.936 -3.856

    minval :

    -7.7853045

    maxval :

    0.0

    array([[ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           [ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           [ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           ...,
           [-6.6424236, -6.3719954, -6.0911098, ..., -3.9788423, -3.7707613,
            -3.6676168],
           [-6.6750154, -6.391214 , -6.0998683, ..., -4.024915 , -3.8421779,
            -3.7519867],
           [-6.7094007, -6.4069495, -6.105737 , ..., -4.099527 , -3.935748 ,
            -3.8563821]], shape=(2500, 33), dtype=float32)

  • upward_sea_water_velocity
    (trajectory, time)
    float32
    0.0 0.0 ... -1.216e-05 -1.716e-05

    minval :

    -0.00363257

    maxval :

    0.0012971408

    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],
           ...,
           [ 2.8918463e-05,  2.3918463e-05,  1.7836926e-05, ...,
            -9.8609635e-06, -1.5731694e-05, -1.8477838e-05],
           [ 2.8918463e-05,  2.3918463e-05,  1.7836926e-05, ...,
            -1.0011416e-05, -1.5489590e-05, -1.8353376e-05],
           [ 2.8918463e-05,  2.3918463e-05,  1.7836926e-05, ...,
            -2.1630735e-06, -1.2163074e-05, -1.7163073e-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 ... 0.3886 0.3754

    minval :

    0.0

    maxval :

    1.6214086

    array([[0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           [0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           [0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           ...,
           [1.2346258 , 1.1221126 , 1.0167016 , ..., 0.39911157, 0.36120534,
            0.34326783],
           [1.2524315 , 1.1323968 , 1.0219352 , ..., 0.4044023 , 0.37174603,
            0.356459  ],
           [1.2719183 , 1.1441381 , 1.0294822 , ..., 0.4178059 , 0.38864955,
            0.37541813]], 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 3.238e+03 ... 2.905e+03

    minval :

    2890.3042

    maxval :

    3247.2253

    array([[3237.6443, 3237.7378, 3237.8003, ..., 3246.9001, 3246.9897,
            3247.068 ],
           [3231.7302, 3231.8508, 3231.952 , ..., 3240.2446, 3240.3276,
            3240.396 ],
           [3226.8372, 3226.9814, 3227.1104, ..., 3234.3474, 3234.447 ,
            3234.5159],
           ...,
           [2909.3318, 2910.1157, 2910.93  , ..., 2920.7495, 2921.1248,
            2921.2952],
           [2900.6626, 2901.5327, 2902.4358, ..., 2912.2507, 2912.6057,
            2912.7754],
           [2890.7188, 2891.7422, 2892.7998, ..., 2904.686 , 2905.016 ,
            2905.1758]], 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 2026-08-21 16:06:35.209003

  date_created :

  2026-08-21T16:06:35.209013

  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 :

  2026-08-21 16:06:29.353264

  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 :

  1.14.10

  seed_geojson :

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

  simulation_time :

  2026-08-21 16:06:35.215810

  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 :

  2026-08-22 08:06:29.353264

  time_coverage_duration :

  P0DT16H0M0S

  time_coverage_resolution :

  P0DT0H15M0S

  performance :

  -------------------- Reader performance: -------------------- https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be 0:00:26.2 total 0:00:00.0 preparing 0:00:25.8 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 0:00:33.4 total 0:00:00.0 preparing 0:00:33.2 reading 0:00:00.1 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: 1:12.3 total time 10.9 configuration 0.0 preparing main loop 0.0 moving elements to ocean 1:01.3 main loop 0.2 updating elements 0.0 cleaning up --------------------

  geospatial_bounds_crs :

  EPSG:4326

  geospatial_bounds_vertical_crs :

  EPSG:5831

  geospatial_lat_min :

  69.7008

  geospatial_lat_max :

  70.83152

  geospatial_lat_units :

  degrees_north

  geospatial_lat_resolution :

  point

  geospatial_lon_min :

  4.8424144

  geospatial_lon_max :

  8.0

  geospatial_lon_units :

  degrees_east

  geospatial_lon_resolution :

  point

  runtime :

  0:01:12.343008

  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
 0:00:26.2  total
 0:00:00.0  preparing
 0:00:25.8  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
 0:00:33.4  total
 0:00:00.0  preparing
 0:00:33.2  reading
 0:00:00.1  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:
 1:12.3 total time
   10.9 configuration
    0.0 preparing main loop
      0.0 moving elements to ocean
 1:01.3 main loop
      0.2 updating elements
    0.0 cleaning up
--------------------
===========================
Model:  OceanDrift     (OpenDrift version 1.14.10)
        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: 2026-08-21 16:06:29.353264 UTC
        Present: 2026-08-22 08:06:29.353264 UTC
        Calculation steps: 64 * 0:15:00 - total time: 16:00:00
        Output steps: 33 * 0:30:00
===========================

16:07:36 WARNING opendrift:2589: Plotting fast. This will make your plots less accurate.
16:07:38 INFO    opendrift:4799: Saving animation to /root/project/docs/source/gallery/animations/example_reader_boundary_0.gif...
16:07:52 INFO    opendrift:3217: Time to make animation: 0:00:15.403848

o.plot(fast=True)

16:07:52 WARNING opendrift:2589: Plotting fast. This will make your plots less accurate.

(<GeoAxes: title={'center': 'OpenDrift - OceanDrift\n2026-08-21 16:06 to 2026-08-22 08:06 UTC (33 steps)'}>, <Figure size 903.005x1100 with 1 Axes>)