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)

09:44:51 INFO    opendrift:576: OpenDriftSimulation initialised (version 1.14.7 / v1.14.7-21-gb739e9e)
09:44:51 INFO    opendrift.readers:63: Opening file with xr.open_dataset
09:44:52 INFO    opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'x': 'X', 'y': 'Y', 'z': 'depth', 'time': 'time'}
09:44:52 INFO    opendrift.readers.basereader:176: Variable x_sea_water_velocity will be rotated from eastward_sea_water_velocity
09:44:52 INFO    opendrift.readers.basereader:176: Variable y_sea_water_velocity will be rotated from northward_sea_water_velocity
09:44:52 INFO    opendrift.readers.basereader:176: Variable x_wind will be rotated from eastward_wind
09:44:52 INFO    opendrift.readers.basereader:176: Variable y_wind will be rotated from northward_wind
09:44:52 INFO    opendrift.readers:63: Opening file with xr.open_dataset
09:44:56 INFO    opendrift.readers.reader_netCDF_CF_generic:332: 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())

09:44:56 INFO    opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
09:45:00 INFO    opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
09:45:00 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_significant_height: 0.000000
09:45:00 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_x_velocity: 0.000000
09:45:00 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_y_velocity: 0.000000
09:45:00 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)

09:45:00 INFO    opendrift:1803: Skipping environment variable ocean_vertical_diffusivity because of condition ['drift:vertical_mixing', 'is', False]
09:45:00 INFO    opendrift:1803: Skipping environment variable ocean_mixed_layer_thickness because of condition ['drift:vertical_mixing', 'is', False]
09:45:00 INFO    opendrift:1814: Storing previous values of element property lon because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
09:45:00 INFO    opendrift:1814: Storing previous values of element property lat because of condition (('general:coastline_action', 'in', ['stranding', 'previous']), 'or', ('general:seafloor_action', 'in', ['previous']))
09:45:00 INFO    opendrift:1822: Storing previous values of environment variable sea_surface_height because of condition ['drift:vertical_advection', 'is', True]
09:45:00 INFO    opendrift:952: Using existing reader for land_binary_mask to move elements to ocean
09:45:00 INFO    opendrift:982: All points are in ocean
09:45:00 INFO    opendrift:2111: 2026-01-09 09:44:56.913433 - step 1 of 64 - 2500 active elements (0 deactivated)
09:45:07 INFO    opendrift:2111: 2026-01-09 09:59:56.913433 - step 2 of 64 - 2500 active elements (0 deactivated)
09:45:08 INFO    opendrift:2111: 2026-01-09 10:14:56.913433 - step 3 of 64 - 2500 active elements (0 deactivated)
09:45:10 INFO    opendrift:2111: 2026-01-09 10:29:56.913433 - step 4 of 64 - 2500 active elements (0 deactivated)
09:45:10 INFO    opendrift:2111: 2026-01-09 10:44:56.913433 - step 5 of 64 - 2500 active elements (0 deactivated)
09:45:11 INFO    opendrift:2111: 2026-01-09 10:59:56.913433 - step 6 of 64 - 2500 active elements (0 deactivated)
09:45:12 INFO    opendrift:2111: 2026-01-09 11:14:56.913433 - step 7 of 64 - 2500 active elements (0 deactivated)
09:45:14 INFO    opendrift:2111: 2026-01-09 11:29:56.913433 - step 8 of 64 - 2500 active elements (0 deactivated)
09:45:15 INFO    opendrift:2111: 2026-01-09 11:44:56.913433 - step 9 of 64 - 2500 active elements (0 deactivated)
09:45:15 INFO    opendrift:2111: 2026-01-09 11:59:56.913433 - step 10 of 64 - 2500 active elements (0 deactivated)
09:45:16 INFO    opendrift:2111: 2026-01-09 12:14:56.913433 - step 11 of 64 - 2500 active elements (0 deactivated)
09:45:18 INFO    opendrift:2111: 2026-01-09 12:29:56.913433 - step 12 of 64 - 2500 active elements (0 deactivated)
09:45:19 INFO    opendrift:2111: 2026-01-09 12:44:56.913433 - step 13 of 64 - 2500 active elements (0 deactivated)
09:45:20 INFO    opendrift:2111: 2026-01-09 12:59:56.913433 - step 14 of 64 - 2500 active elements (0 deactivated)
09:45:20 INFO    opendrift:2111: 2026-01-09 13:14:56.913433 - step 15 of 64 - 2500 active elements (0 deactivated)
09:45:23 INFO    opendrift:2111: 2026-01-09 13:29:56.913433 - step 16 of 64 - 2500 active elements (0 deactivated)
09:45:23 INFO    opendrift:2111: 2026-01-09 13:44:56.913433 - step 17 of 64 - 2500 active elements (0 deactivated)
09:45:24 INFO    opendrift:2111: 2026-01-09 13:59:56.913433 - step 18 of 64 - 2500 active elements (0 deactivated)
09:45:25 INFO    opendrift:2111: 2026-01-09 14:14:56.913433 - step 19 of 64 - 2500 active elements (0 deactivated)
09:45:27 INFO    opendrift:2111: 2026-01-09 14:29:56.913433 - step 20 of 64 - 2500 active elements (0 deactivated)
09:45:28 INFO    opendrift:2111: 2026-01-09 14:44:56.913433 - step 21 of 64 - 2500 active elements (0 deactivated)
09:45:28 INFO    opendrift:2111: 2026-01-09 14:59:56.913433 - step 22 of 64 - 2500 active elements (0 deactivated)
09:45:29 INFO    opendrift:2111: 2026-01-09 15:14:56.913433 - step 23 of 64 - 2500 active elements (0 deactivated)
09:45:32 INFO    opendrift:2111: 2026-01-09 15:29:56.913433 - step 24 of 64 - 2500 active elements (0 deactivated)
09:45:32 INFO    opendrift:2111: 2026-01-09 15:44:56.913433 - step 25 of 64 - 2500 active elements (0 deactivated)
09:45:33 INFO    opendrift:2111: 2026-01-09 15:59:56.913433 - step 26 of 64 - 2500 active elements (0 deactivated)
09:45:34 INFO    opendrift:2111: 2026-01-09 16:14:56.913433 - step 27 of 64 - 2500 active elements (0 deactivated)
09:45:36 INFO    opendrift:2111: 2026-01-09 16:29:56.913433 - step 28 of 64 - 2500 active elements (0 deactivated)
09:45:37 INFO    opendrift:2111: 2026-01-09 16:44:56.913433 - step 29 of 64 - 2500 active elements (0 deactivated)
09:45:37 INFO    opendrift:2111: 2026-01-09 16:59:56.913433 - step 30 of 64 - 2500 active elements (0 deactivated)
09:45:38 INFO    opendrift:2111: 2026-01-09 17:14:56.913433 - step 31 of 64 - 2500 active elements (0 deactivated)
09:45:40 INFO    opendrift:2111: 2026-01-09 17:29:56.913433 - step 32 of 64 - 2500 active elements (0 deactivated)
09:45:41 INFO    opendrift:2111: 2026-01-09 17:44:56.913433 - step 33 of 64 - 2500 active elements (0 deactivated)
09:45:42 INFO    opendrift:2111: 2026-01-09 17:59:56.913433 - step 34 of 64 - 2500 active elements (0 deactivated)
09:45:42 INFO    opendrift:2111: 2026-01-09 18:14:56.913433 - step 35 of 64 - 2500 active elements (0 deactivated)
09:45:45 INFO    opendrift:2111: 2026-01-09 18:29:56.913433 - step 36 of 64 - 2500 active elements (0 deactivated)
09:45:45 INFO    opendrift:2111: 2026-01-09 18:44:56.913433 - step 37 of 64 - 2500 active elements (0 deactivated)
09:45:46 INFO    opendrift:2111: 2026-01-09 18:59:56.913433 - step 38 of 64 - 2500 active elements (0 deactivated)
09:45:47 INFO    opendrift:2111: 2026-01-09 19:14:56.913433 - step 39 of 64 - 2500 active elements (0 deactivated)
09:45:49 INFO    opendrift:2111: 2026-01-09 19:29:56.913433 - step 40 of 64 - 2500 active elements (0 deactivated)
09:45:50 INFO    opendrift:2111: 2026-01-09 19:44:56.913433 - step 41 of 64 - 2500 active elements (0 deactivated)
09:45:51 INFO    opendrift:2111: 2026-01-09 19:59:56.913433 - step 42 of 64 - 2500 active elements (0 deactivated)
09:45:51 INFO    opendrift:2111: 2026-01-09 20:14:56.913433 - step 43 of 64 - 2500 active elements (0 deactivated)
09:45:55 INFO    opendrift:2111: 2026-01-09 20:29:56.913433 - step 44 of 64 - 2500 active elements (0 deactivated)
09:45:55 INFO    opendrift:2111: 2026-01-09 20:44:56.913433 - step 45 of 64 - 2500 active elements (0 deactivated)
09:45:56 INFO    opendrift:2111: 2026-01-09 20:59:56.913433 - step 46 of 64 - 2500 active elements (0 deactivated)
09:45:57 INFO    opendrift:2111: 2026-01-09 21:14:56.913433 - step 47 of 64 - 2500 active elements (0 deactivated)
09:46:00 INFO    opendrift:2111: 2026-01-09 21:29:56.913433 - step 48 of 64 - 2500 active elements (0 deactivated)
09:46:01 INFO    opendrift:2111: 2026-01-09 21:44:56.913433 - step 49 of 64 - 2500 active elements (0 deactivated)
09:46:02 INFO    opendrift:2111: 2026-01-09 21:59:56.913433 - step 50 of 64 - 2500 active elements (0 deactivated)
09:46:03 INFO    opendrift:2111: 2026-01-09 22:14:56.913433 - step 51 of 64 - 2500 active elements (0 deactivated)
09:46:05 INFO    opendrift:2111: 2026-01-09 22:29:56.913433 - step 52 of 64 - 2500 active elements (0 deactivated)
09:46:06 INFO    opendrift:2111: 2026-01-09 22:44:56.913433 - step 53 of 64 - 2500 active elements (0 deactivated)
09:46:07 INFO    opendrift:2111: 2026-01-09 22:59:56.913433 - step 54 of 64 - 2500 active elements (0 deactivated)
09:46:07 INFO    opendrift:2111: 2026-01-09 23:14:56.913433 - step 55 of 64 - 2500 active elements (0 deactivated)
09:46:10 INFO    opendrift:2111: 2026-01-09 23:29:56.913433 - step 56 of 64 - 2500 active elements (0 deactivated)
09:46:11 INFO    opendrift:2111: 2026-01-09 23:44:56.913433 - step 57 of 64 - 2500 active elements (0 deactivated)
09:46:12 INFO    opendrift:2111: 2026-01-09 23:59:56.913433 - step 58 of 64 - 2500 active elements (0 deactivated)
09:46:13 INFO    opendrift:2111: 2026-01-10 00:14:56.913433 - step 59 of 64 - 2500 active elements (0 deactivated)
09:46:15 INFO    opendrift:2111: 2026-01-10 00:29:56.913433 - step 60 of 64 - 2500 active elements (0 deactivated)
09:46:16 INFO    opendrift:2111: 2026-01-10 00:44:56.913433 - step 61 of 64 - 2500 active elements (0 deactivated)
09:46:16 INFO    opendrift:2111: 2026-01-10 00:59:56.913433 - step 62 of 64 - 2500 active elements (0 deactivated)
09:46:17 INFO    opendrift:2111: 2026-01-10 01:14:56.913433 - step 63 of 64 - 2500 active elements (0 deactivated)
09:46:20 INFO    opendrift:2111: 2026-01-10 01:29:56.913433 - 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: (12/21)
    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 ...
    ...                                        ...
    upward_sea_water_velocity                 (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: (12/119)
    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]
    2026-01-09T09:44:56.913433 ... 2...

    standard_name :

    time

    long_name :

    time

    dtype :

    <class 'numpy.float64'>

    array(['2026-01-09T09:44:56.913433000', '2026-01-09T10:14:56.913433000',
           '2026-01-09T10:44:56.913433000', '2026-01-09T11:14:56.913433000',
           '2026-01-09T11:44:56.913433000', '2026-01-09T12:14:56.913433000',
           '2026-01-09T12:44:56.913433000', '2026-01-09T13:14:56.913433000',
           '2026-01-09T13:44:56.913433000', '2026-01-09T14:14:56.913433000',
           '2026-01-09T14:44:56.913433000', '2026-01-09T15:14:56.913433000',
           '2026-01-09T15:44:56.913433000', '2026-01-09T16:14:56.913433000',
           '2026-01-09T16:44:56.913433000', '2026-01-09T17:14:56.913433000',
           '2026-01-09T17:44:56.913433000', '2026-01-09T18:14:56.913433000',
           '2026-01-09T18:44:56.913433000', '2026-01-09T19:14:56.913433000',
           '2026-01-09T19:44:56.913433000', '2026-01-09T20:14:56.913433000',
           '2026-01-09T20:44:56.913433000', '2026-01-09T21:14:56.913433000',
           '2026-01-09T21:44:56.913433000', '2026-01-09T22:14:56.913433000',
           '2026-01-09T22:44:56.913433000', '2026-01-09T23:14:56.913433000',
           '2026-01-09T23:44:56.913433000', '2026-01-10T00:14:56.913433000',
           '2026-01-10T00:44:56.913433000', '2026-01-10T01:14:56.913433000',
           '2026-01-10T01:44:56.913433000'], dtype='datetime64[ns]')

• Data variables: (21)
  • 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 4.996 4.993 ... 7.651 7.634

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_east

    standard_name :

    longitude

    long_name :

    longitude

    axis :

    X

    minval :

    4.7617416

    maxval :

    8.021644

    array([[5.       , 4.996184 , 4.992554 , ..., 4.939245 , 4.9400682,
            4.9416423],
           [5.0612245, 5.057646 , 5.054277 , ..., 5.006317 , 5.007418 ,
            5.009264 ],
           [5.122449 , 5.11881  , 5.115437 , ..., 5.0703673, 5.0716066,
            5.073585 ],
           ...,
           [7.877551 , 7.875028 , 7.87243  , ..., 7.522255 , 7.5043874,
            7.486707 ],
           [7.9387755, 7.937763 , 7.9371715, ..., 7.586576 , 7.5692067,
            7.551713 ],
           [8.       , 7.998567 , 7.9981527, ..., 7.6670346, 7.650886 ,
            7.634466 ]], shape=(2500, 33), dtype=float32)

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

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_north

    standard_name :

    latitude

    long_name :

    latitude

    axis :

    Y

    minval :

    69.79722

    maxval :

    70.89393

    array([[69.8     , 69.800865, 69.801895, ..., 69.83827 , 69.84017 ,
            69.84215 ],
           [69.8     , 69.80094 , 69.802055, ..., 69.838165, 69.84005 ,
            69.84199 ],
           [69.8     , 69.80111 , 69.80239 , ..., 69.839745, 69.84165 ,
            69.84362 ],
           ...,
           [70.8     , 70.80517 , 70.81006 , ..., 70.83157 , 70.828384,
            70.82539 ],
           [70.8     , 70.80565 , 70.81101 , ..., 70.86536 , 70.862206,
            70.85878 ],
           [70.8     , 70.80574 , 70.811485, ..., 70.89372 , 70.89267 ,
            70.89099 ]], 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
    -0.08241 -0.07909 ... -0.09487

    minval :

    -0.46348557

    maxval :

    0.2975364

    array([[-0.08240853, -0.07908896, -0.07308288, ...,  0.01356813,
             0.02968524,  0.03760847],
           [-0.07746113, -0.07360484, -0.0672237 , ...,  0.01952877,
             0.0355393 ,  0.04337426],
           [-0.07904609, -0.07398506, -0.06643113, ...,  0.02251427,
             0.03840462,  0.04615909],
           ...,
           [ 0.14666884,  0.15202741,  0.15143979, ..., -0.11933776,
            -0.11865678, -0.11650663],
           [ 0.1751576 ,  0.19043815,  0.19556478, ..., -0.10991976,
            -0.11358595, -0.1156883 ],
           [ 0.1635914 ,  0.18974738,  0.21168424, ..., -0.0858624 ,
            -0.09093218, -0.09486712]], shape=(2500, 33), dtype=float32)

  • y_sea_water_velocity
    (trajectory, time)
    float32
    0.05071 0.06139 ... -0.1691 -0.1876

    minval :

    -0.7355889

    maxval :

    0.5209865

    array([[ 0.05070768,  0.06138881,  0.07230593, ...,  0.11668148,
             0.12149393,  0.12305961],
           [ 0.05545677,  0.06631324,  0.07735184, ...,  0.11539614,
             0.11948141,  0.12067576],
           [ 0.06617244,  0.07672996,  0.08718277, ...,  0.11736286,
             0.12139507,  0.12254967],
           ...,
           [ 0.27035114,  0.2511139 ,  0.23062627, ..., -0.26161706,
            -0.25630605, -0.24666126],
           [ 0.29934973,  0.2810625 ,  0.25426236, ..., -0.25983214,
            -0.28076136, -0.2864207 ],
           [ 0.30072746,  0.30022475,  0.29034388, ..., -0.1278984 ,
            -0.16906053, -0.18763214]], shape=(2500, 33), dtype=float32)

  • sea_surface_height
    (trajectory, time)
    float32
    -1.214 -1.173 ... -0.765 -0.6997

    minval :

    -1.3554761

    maxval :

    0.17244358

    array([[-1.2136021 , -1.1732837 , -1.1028448 , ..., -0.97268015,
            -0.8620599 , -0.8056273 ],
           [-1.2150869 , -1.1747847 , -1.1043047 , ..., -0.9743905 ,
            -0.86358565, -0.8070434 ],
           [-1.216386  , -1.1761733 , -1.1057417 , ..., -0.9762704 ,
            -0.8652789 , -0.80862844],
           ...,
           [-1.092436  , -1.0465693 , -0.96700037, ..., -0.86945784,
            -0.74084187, -0.67515874],
           [-1.0882338 , -1.0429071 , -0.96352804, ..., -0.88056153,
            -0.7521305 , -0.6863681 ],
           [-1.0836837 , -1.0383161 , -0.9592253 , ..., -0.89195997,
            -0.7649679 , -0.69965136]], shape=(2500, 33), dtype=float32)

  • x_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... -12.04 -12.06 -12.0

    minval :

    -17.194326

    maxval :

    0.0

    array([[  0.       ,   0.       ,   0.       , ...,   0.       ,
              0.       ,   0.       ],
           [  0.       ,   0.       ,   0.       , ...,   0.       ,
              0.       ,   0.       ],
           [  0.       ,   0.       ,   0.       , ...,   0.       ,
              0.       ,   0.       ],
           ...,
           [ -9.966922 , -10.196743 , -10.402654 , ..., -12.164786 ,
            -12.174434 , -12.087522 ],
           [ -9.952362 , -10.181584 , -10.377767 , ..., -12.081888 ,
            -12.094032 , -12.021881 ],
           [ -9.909357 , -10.144584 , -10.3427925, ..., -12.035935 ,
            -12.057586 , -11.995431 ]], shape=(2500, 33), dtype=float32)

  • y_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 3.788 3.663 3.777

    minval :

    0.0

    maxval :

    7.5934196

    array([[0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           ...,
           [2.7307184, 2.7939258, 3.0904844, ..., 3.4043822, 3.2199728,
            3.366138 ],
           [2.7456253, 2.8115845, 3.1109405, ..., 3.6615202, 3.5111961,
            3.634432 ],
           [2.752893 , 2.824875 , 3.133243 , ..., 3.7880712, 3.66283  ,
            3.777132 ]], shape=(2500, 33), dtype=float32)

  • upward_sea_water_velocity
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 6.43e-05 6.152e-05

    minval :

    -0.0080941245

    maxval :

    0.00814955

    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],
           ...,
           [1.2474278e-05, 3.1905030e-05, 5.1635001e-05, ..., 5.1022085e-05,
            4.8530641e-05, 4.6019493e-05],
           [1.6570584e-05, 3.1115142e-05, 4.9965704e-05, ..., 5.5160443e-05,
            5.2864685e-05, 5.0514911e-05],
           [1.9965704e-05, 3.7474278e-05, 5.2474279e-05, ..., 6.6656517e-05,
            6.4298249e-05, 6.1517167e-05]], shape=(2500, 33), dtype=float32)

  • sea_surface_wave_significant_height
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 3.917 3.907 3.891

    minval :

    0.0

    maxval :

    7.433616

    array([[0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           [0.       , 0.       , 0.       , ..., 0.       , 0.       ,
            0.       ],
           ...,
           [2.6271904, 2.749778 , 2.897051 , ..., 3.925467 , 3.901193 ,
            3.873001 ],
           [2.622064 , 2.744614 , 2.887449 , ..., 3.9207172, 3.9014149,
            3.8802738],
           [2.602035 , 2.7279553, 2.873048 , ..., 3.9166453, 3.9065213,
            3.8906646]], 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 ... 2.95e+03

    minval :

    2884.313

    maxval :

    3240.2114

    array([[3237.6443, 3237.9988, 3238.3264, ..., 3239.5972, 3239.1833,
            3238.938 ],
           [3231.7302, 3231.995 , 3232.2373, ..., 3233.177 , 3232.8213,
            3232.6118],
           [3226.837 , 3227.088 , 3227.314 , ..., 3227.67  , 3227.3699,
            3227.196 ],
           ...,
           [2909.3318, 2908.817 , 2908.345 , ..., 2963.8726, 2963.5886,
            2963.7798],
           [2900.6626, 2900.0276, 2899.3108, ..., 2962.0466, 2961.8806,
            2961.567 ],
           [2890.719 , 2890.147 , 2889.3528, ..., 2941.213 , 2947.215 ,
            2949.9653]], 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)

• Indexes: (2)
  • trajectory
    PandasIndex

    PandasIndex(Index([   0,    1,    2,    3,    4,    5,    6,    7,    8,    9,
           ...
           2490, 2491, 2492, 2493, 2494, 2495, 2496, 2497, 2498, 2499],
          dtype='int64', name='trajectory', length=2500))

  • time
    PandasIndex

    PandasIndex(DatetimeIndex(['2026-01-09 09:44:56.913433', '2026-01-09 10:14:56.913433',
                   '2026-01-09 10:44:56.913433', '2026-01-09 11:14:56.913433',
                   '2026-01-09 11:44:56.913433', '2026-01-09 12:14:56.913433',
                   '2026-01-09 12:44:56.913433', '2026-01-09 13:14:56.913433',
                   '2026-01-09 13:44:56.913433', '2026-01-09 14:14:56.913433',
                   '2026-01-09 14:44:56.913433', '2026-01-09 15:14:56.913433',
                   '2026-01-09 15:44:56.913433', '2026-01-09 16:14:56.913433',
                   '2026-01-09 16:44:56.913433', '2026-01-09 17:14:56.913433',
                   '2026-01-09 17:44:56.913433', '2026-01-09 18:14:56.913433',
                   '2026-01-09 18:44:56.913433', '2026-01-09 19:14:56.913433',
                   '2026-01-09 19:44:56.913433', '2026-01-09 20:14:56.913433',
                   '2026-01-09 20:44:56.913433', '2026-01-09 21:14:56.913433',
                   '2026-01-09 21:44:56.913433', '2026-01-09 22:14:56.913433',
                   '2026-01-09 22:44:56.913433', '2026-01-09 23:14:56.913433',
                   '2026-01-09 23:44:56.913433', '2026-01-10 00:14:56.913433',
                   '2026-01-10 00:44:56.913433', '2026-01-10 01:14:56.913433',
                   '2026-01-10 01:44:56.913433'],
                  dtype='datetime64[ns]', name='time', freq='30min'))

• Attributes: (119)

  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 2026-01-09 09:45:00.984447

  date_created :

  2026-01-09T09:45:00.984462

  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 :

  2026-01-09 09:44:56.913433

  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: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:horizontal_diffusivity :

  0

  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 :

  1.14.7

  seed_geojson :

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

  simulation_time :

  2026-01-09 09:45:00.992696

  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_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 :

  2026-01-10 01:44:56.913433

  time_coverage_duration :

  P0DT16H0M0S

  time_coverage_resolution :

  P0DT0H15M0S

  performance :

  -------------------- Reader performance: -------------------- https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be 0:00:34.0 total 0:00:00.0 preparing 0:00:33.6 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 0:00:44.4 total 0:00:00.0 preparing 0:00:44.2 reading 0:00:00.0 interpolation 0:00:00.0 interpolation_time 0:00:00.1 rotating vectors 0:00:00.0 masking -------------------- global_landmask 0:00:00.0 total 0:00:00.0 preparing 0:00:00.0 reading 0:00:00.0 masking -------------------- Performance: 1:30.2 total time 9.9 configuration 0.0 preparing main loop 0.0 moving elements to ocean 1:20.2 main loop 0.2 updating elements 0.0 cleaning up --------------------

  geospatial_bounds_crs :

  EPSG:4326

  geospatial_bounds_vertical_crs :

  EPSG:5831

  geospatial_lat_min :

  69.79722

  geospatial_lat_max :

  70.89393

  geospatial_lat_units :

  degrees_north

  geospatial_lat_resolution :

  point

  geospatial_lon_min :

  4.7617416

  geospatial_lon_max :

  8.021644

  geospatial_lon_units :

  degrees_east

  geospatial_lon_resolution :

  point

  runtime :

  0:01:30.262462

  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
 0:00:34.0  total
 0:00:00.0  preparing
 0:00:33.6  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
 0:00:44.4  total
 0:00:00.0  preparing
 0:00:44.2  reading
 0:00:00.0  interpolation
 0:00:00.0  interpolation_time
 0:00:00.1  rotating vectors
 0:00:00.0  masking
--------------------
global_landmask
 0:00:00.0  total
 0:00:00.0  preparing
 0:00:00.0  reading
 0:00:00.0  masking
--------------------
Performance:
 1:30.2 total time
    9.9 configuration
    0.0 preparing main loop
      0.0 moving elements to ocean
 1:20.2 main loop
      0.2 updating elements
    0.0 cleaning up
--------------------
===========================
Model:  OceanDrift     (OpenDrift version 1.14.7)
        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:
  sea_surface_wave_significant_height
  sea_surface_wave_stokes_drift_x_velocity
  sea_surface_wave_stokes_drift_y_velocity

Discarded readers:

Time:
        Start: 2026-01-09 09:44:56.913433 UTC
        Present: 2026-01-10 01:44:56.913433 UTC
        Calculation steps: 64 * 0:15:00 - total time: 16:00:00
        Output steps: 33 * 0:30:00
===========================

09:46:21 WARNING opendrift:2473: Plotting fast. This will make your plots less accurate.
09:46:22 INFO    opendrift:4660: Saving animation to /root/project/docs/source/gallery/animations/example_reader_boundary_0.gif...
09:46:44 INFO    opendrift:3094: Time to make animation: 0:00:23.227386

o.plot(fast=True)

09:46:44 WARNING opendrift:2473: Plotting fast. This will make your plots less accurate.

(<GeoAxes: title={'center': 'OpenDrift - OceanDrift\n2026-01-09 09:44 to 2026-01-10 01:44 UTC (33 steps)'}>, <Figure size 930.151x1100 with 1 Axes>)