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)

09:20:19 INFO    opendrift:576: OpenDriftSimulation initialised (version 1.14.7 / v1.14.7-2-g52ef046)
09:20:19 INFO    opendrift.readers:63: Opening file with xr.open_dataset
09:20:20 INFO    opendrift.readers.reader_netCDF_CF_generic:332: Detected dimensions: {'x': 'X', 'y': 'Y', 'z': 'depth', 'time': 'time'}
09:20:20 INFO    opendrift.readers.basereader:176: Variable x_sea_water_velocity will be rotated from eastward_sea_water_velocity
09:20:20 INFO    opendrift.readers.basereader:176: Variable y_sea_water_velocity will be rotated from northward_sea_water_velocity
09:20:20 INFO    opendrift.readers.basereader:176: Variable x_wind will be rotated from eastward_wind
09:20:20 INFO    opendrift.readers.basereader:176: Variable y_wind will be rotated from northward_wind
09:20:20 INFO    opendrift.readers:63: Opening file with xr.open_dataset
09:20:22 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())

09:20:22 INFO    opendrift.models.basemodel.environment:203: Adding a global landmask from GSHHG
09:20:27 INFO    opendrift.models.basemodel.environment:227: Fallback values will be used for the following variables which have no readers:
09:20:27 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_significant_height: 0.000000
09:20:27 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_x_velocity: 0.000000
09:20:27 INFO    opendrift.models.basemodel.environment:230:    sea_surface_wave_stokes_drift_y_velocity: 0.000000
09:20:27 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)

09:20:27 INFO    opendrift:1803: Skipping environment variable ocean_vertical_diffusivity because of condition ['drift:vertical_mixing', 'is', False]
09:20:27 INFO    opendrift:1803: Skipping environment variable ocean_mixed_layer_thickness because of condition ['drift:vertical_mixing', 'is', False]
09:20:27 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']))
09:20:27 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']))
09:20:27 INFO    opendrift:1822: Storing previous values of environment variable sea_surface_height because of condition ['drift:vertical_advection', 'is', True]
09:20:27 INFO    opendrift:952: Using existing reader for land_binary_mask to move elements to ocean
09:20:27 INFO    opendrift:982: All points are in ocean
09:20:27 INFO    opendrift:2111: 2025-12-05 09:20:22.628439 - step 1 of 64 - 2500 active elements (0 deactivated)
09:20:31 INFO    opendrift:2111: 2025-12-05 09:35:22.628439 - step 2 of 64 - 2500 active elements (0 deactivated)
09:20:32 INFO    opendrift:2111: 2025-12-05 09:50:22.628439 - step 3 of 64 - 2500 active elements (0 deactivated)
09:20:33 INFO    opendrift:2111: 2025-12-05 10:05:22.628439 - step 4 of 64 - 2500 active elements (0 deactivated)
09:20:35 INFO    opendrift:2111: 2025-12-05 10:20:22.628439 - step 5 of 64 - 2500 active elements (0 deactivated)
09:20:36 INFO    opendrift:2111: 2025-12-05 10:35:22.628439 - step 6 of 64 - 2500 active elements (0 deactivated)
09:20:37 INFO    opendrift:2111: 2025-12-05 10:50:22.628439 - step 7 of 64 - 2500 active elements (0 deactivated)
09:20:37 INFO    opendrift:2111: 2025-12-05 11:05:22.628439 - step 8 of 64 - 2500 active elements (0 deactivated)
09:20:40 INFO    opendrift:2111: 2025-12-05 11:20:22.628439 - step 9 of 64 - 2500 active elements (0 deactivated)
09:20:40 INFO    opendrift:2111: 2025-12-05 11:35:22.628439 - step 10 of 64 - 2500 active elements (0 deactivated)
09:20:41 INFO    opendrift:2111: 2025-12-05 11:50:22.628439 - step 11 of 64 - 2500 active elements (0 deactivated)
09:20:42 INFO    opendrift:2111: 2025-12-05 12:05:22.628439 - step 12 of 64 - 2500 active elements (0 deactivated)
09:20:44 INFO    opendrift:2111: 2025-12-05 12:20:22.628439 - step 13 of 64 - 2500 active elements (0 deactivated)
09:20:45 INFO    opendrift:2111: 2025-12-05 12:35:22.628439 - step 14 of 64 - 2500 active elements (0 deactivated)
09:20:46 INFO    opendrift:2111: 2025-12-05 12:50:22.628439 - step 15 of 64 - 2500 active elements (0 deactivated)
09:20:46 INFO    opendrift:2111: 2025-12-05 13:05:22.628439 - step 16 of 64 - 2500 active elements (0 deactivated)
09:20:49 INFO    opendrift:2111: 2025-12-05 13:20:22.628439 - step 17 of 64 - 2500 active elements (0 deactivated)
09:20:50 INFO    opendrift:2111: 2025-12-05 13:35:22.628439 - step 18 of 64 - 2500 active elements (0 deactivated)
09:20:50 INFO    opendrift:2111: 2025-12-05 13:50:22.628439 - step 19 of 64 - 2500 active elements (0 deactivated)
09:20:51 INFO    opendrift:2111: 2025-12-05 14:05:22.628439 - step 20 of 64 - 2500 active elements (0 deactivated)
09:20:54 INFO    opendrift:2111: 2025-12-05 14:20:22.628439 - step 21 of 64 - 2500 active elements (0 deactivated)
09:20:54 INFO    opendrift:2111: 2025-12-05 14:35:22.628439 - step 22 of 64 - 2500 active elements (0 deactivated)
09:20:55 INFO    opendrift:2111: 2025-12-05 14:50:22.628439 - step 23 of 64 - 2500 active elements (0 deactivated)
09:20:56 INFO    opendrift:2111: 2025-12-05 15:05:22.628439 - step 24 of 64 - 2500 active elements (0 deactivated)
09:20:59 INFO    opendrift:2111: 2025-12-05 15:20:22.628439 - step 25 of 64 - 2500 active elements (0 deactivated)
09:20:59 INFO    opendrift:2111: 2025-12-05 15:35:22.628439 - step 26 of 64 - 2500 active elements (0 deactivated)
09:21:00 INFO    opendrift:2111: 2025-12-05 15:50:22.628439 - step 27 of 64 - 2500 active elements (0 deactivated)
09:21:01 INFO    opendrift:2111: 2025-12-05 16:05:22.628439 - step 28 of 64 - 2500 active elements (0 deactivated)
09:21:03 INFO    opendrift:2111: 2025-12-05 16:20:22.628439 - step 29 of 64 - 2500 active elements (0 deactivated)
09:21:04 INFO    opendrift:2111: 2025-12-05 16:35:22.628439 - step 30 of 64 - 2500 active elements (0 deactivated)
09:21:05 INFO    opendrift:2111: 2025-12-05 16:50:22.628439 - step 31 of 64 - 2500 active elements (0 deactivated)
09:21:05 INFO    opendrift:2111: 2025-12-05 17:05:22.628439 - step 32 of 64 - 2500 active elements (0 deactivated)
09:21:08 INFO    opendrift:2111: 2025-12-05 17:20:22.628439 - step 33 of 64 - 2500 active elements (0 deactivated)
09:21:08 INFO    opendrift:2111: 2025-12-05 17:35:22.628439 - step 34 of 64 - 2500 active elements (0 deactivated)
09:21:09 INFO    opendrift:2111: 2025-12-05 17:50:22.628439 - step 35 of 64 - 2500 active elements (0 deactivated)
09:21:10 INFO    opendrift:2111: 2025-12-05 18:05:22.628439 - step 36 of 64 - 2500 active elements (0 deactivated)
09:21:13 INFO    opendrift:2111: 2025-12-05 18:20:22.628439 - step 37 of 64 - 2500 active elements (0 deactivated)
09:21:13 INFO    opendrift:2111: 2025-12-05 18:35:22.628439 - step 38 of 64 - 2500 active elements (0 deactivated)
09:21:14 INFO    opendrift:2111: 2025-12-05 18:50:22.628439 - step 39 of 64 - 2500 active elements (0 deactivated)
09:21:15 INFO    opendrift:2111: 2025-12-05 19:05:22.628439 - step 40 of 64 - 2500 active elements (0 deactivated)
09:21:17 INFO    opendrift:2111: 2025-12-05 19:20:22.628439 - step 41 of 64 - 2500 active elements (0 deactivated)
09:21:18 INFO    opendrift:2111: 2025-12-05 19:35:22.628439 - step 42 of 64 - 2500 active elements (0 deactivated)
09:21:18 INFO    opendrift:2111: 2025-12-05 19:50:22.628439 - step 43 of 64 - 2500 active elements (0 deactivated)
09:21:19 INFO    opendrift:2111: 2025-12-05 20:05:22.628439 - step 44 of 64 - 2500 active elements (0 deactivated)
09:21:22 INFO    opendrift:2111: 2025-12-05 20:20:22.628439 - step 45 of 64 - 2500 active elements (0 deactivated)
09:21:22 INFO    opendrift:2111: 2025-12-05 20:35:22.628439 - step 46 of 64 - 2500 active elements (0 deactivated)
09:21:23 INFO    opendrift:2111: 2025-12-05 20:50:22.628439 - step 47 of 64 - 2500 active elements (0 deactivated)
09:21:24 INFO    opendrift:2111: 2025-12-05 21:05:22.628439 - step 48 of 64 - 2500 active elements (0 deactivated)
09:21:27 INFO    opendrift:2111: 2025-12-05 21:20:22.628439 - step 49 of 64 - 2500 active elements (0 deactivated)
09:21:28 INFO    opendrift:2111: 2025-12-05 21:35:22.628439 - step 50 of 64 - 2500 active elements (0 deactivated)
09:21:29 INFO    opendrift:2111: 2025-12-05 21:50:22.628439 - step 51 of 64 - 2500 active elements (0 deactivated)
09:21:29 INFO    opendrift:2111: 2025-12-05 22:05:22.628439 - step 52 of 64 - 2500 active elements (0 deactivated)
09:21:32 INFO    opendrift:2111: 2025-12-05 22:20:22.628439 - step 53 of 64 - 2500 active elements (0 deactivated)
09:21:33 INFO    opendrift:2111: 2025-12-05 22:35:22.628439 - step 54 of 64 - 2500 active elements (0 deactivated)
09:21:33 INFO    opendrift:2111: 2025-12-05 22:50:22.628439 - step 55 of 64 - 2500 active elements (0 deactivated)
09:21:34 INFO    opendrift:2111: 2025-12-05 23:05:22.628439 - step 56 of 64 - 2500 active elements (0 deactivated)
09:21:36 INFO    opendrift:2111: 2025-12-05 23:20:22.628439 - step 57 of 64 - 2500 active elements (0 deactivated)
09:21:37 INFO    opendrift:2111: 2025-12-05 23:35:22.628439 - step 58 of 64 - 2500 active elements (0 deactivated)
09:21:38 INFO    opendrift:2111: 2025-12-05 23:50:22.628439 - step 59 of 64 - 2500 active elements (0 deactivated)
09:21:38 INFO    opendrift:2111: 2025-12-06 00:05:22.628439 - step 60 of 64 - 2500 active elements (0 deactivated)
09:21:41 INFO    opendrift:2111: 2025-12-06 00:20:22.628439 - step 61 of 64 - 2500 active elements (0 deactivated)
09:21:42 INFO    opendrift:2111: 2025-12-06 00:35:22.628439 - step 62 of 64 - 2500 active elements (0 deactivated)
09:21:42 INFO    opendrift:2111: 2025-12-06 00:50:22.628439 - step 63 of 64 - 2500 active elements (0 deactivated)
09:21:43 INFO    opendrift:2111: 2025-12-06 01:05:22.628439 - 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 2025...
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]
    2025-12-05T09:20:22.628439 ... 2...

    standard_name :

    time

    long_name :

    time

    dtype :

    <class 'numpy.float64'>

    array(['2025-12-05T09:20:22.628439000', '2025-12-05T09:50:22.628439000',
           '2025-12-05T10:20:22.628439000', '2025-12-05T10:50:22.628439000',
           '2025-12-05T11:20:22.628439000', '2025-12-05T11:50:22.628439000',
           '2025-12-05T12:20:22.628439000', '2025-12-05T12:50:22.628439000',
           '2025-12-05T13:20:22.628439000', '2025-12-05T13:50:22.628439000',
           '2025-12-05T14:20:22.628439000', '2025-12-05T14:50:22.628439000',
           '2025-12-05T15:20:22.628439000', '2025-12-05T15:50:22.628439000',
           '2025-12-05T16:20:22.628439000', '2025-12-05T16:50:22.628439000',
           '2025-12-05T17:20:22.628439000', '2025-12-05T17:50:22.628439000',
           '2025-12-05T18:20:22.628439000', '2025-12-05T18:50:22.628439000',
           '2025-12-05T19:20:22.628439000', '2025-12-05T19:50:22.628439000',
           '2025-12-05T20:20:22.628439000', '2025-12-05T20:50:22.628439000',
           '2025-12-05T21:20:22.628439000', '2025-12-05T21:50:22.628439000',
           '2025-12-05T22:20:22.628439000', '2025-12-05T22:50:22.628439000',
           '2025-12-05T23:20:22.628439000', '2025-12-05T23:50:22.628439000',
           '2025-12-06T00:20:22.628439000', '2025-12-06T00:50:22.628439000',
           '2025-12-06T01:20:22.628439000'], 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 4.999 4.998 ... 7.732 7.727

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_east

    standard_name :

    longitude

    long_name :

    longitude

    axis :

    X

    minval :

    4.871834

    maxval :

    8.0

    array([[5.       , 4.998752 , 4.9980035, ..., 4.9585047, 4.961583 ,
            4.9643307],
           [5.0612245, 5.060468 , 5.0602226, ..., 5.027398 , 5.030529 ,
            5.033273 ],
           [5.122449 , 5.122102 , 5.1222773, ..., 5.098037 , 5.1014285,
            5.104398 ],
           ...,
           [7.877551 , 7.868935 , 7.8599696, ..., 7.6294746, 7.625914 ,
            7.6222906],
           [7.9387755, 7.930161 , 7.9212193, ..., 7.681012 , 7.6772537,
            7.6733375],
           [8.       , 7.9915733, 7.9827237, ..., 7.7356415, 7.731505 ,
            7.72714  ]], shape=(2500, 33), dtype=float32)

  • lat
    (trajectory, time)
    float32
    69.8 69.8 69.8 ... 70.76 70.75

    dtype :

    <class 'numpy.float32'>

    units :

    degrees_north

    standard_name :

    latitude

    long_name :

    latitude

    axis :

    Y

    minval :

    69.77808

    maxval :

    70.85056

    array([[69.8     , 69.80222 , 69.804375, ..., 69.84087 , 69.84194 ,
            69.8427  ],
           [69.8     , 69.80236 , 69.80466 , ..., 69.8402  , 69.84107 ,
            69.84163 ],
           [69.8     , 69.802475, 69.80488 , ..., 69.84233 , 69.84314 ,
            69.843636],
           ...,
           [70.8     , 70.79776 , 70.79557 , ..., 70.75532 , 70.75433 ,
            70.75322 ],
           [70.8     , 70.79781 , 70.79571 , ..., 70.754906, 70.75381 ,
            70.75259 ],
           [70.8     , 70.79782 , 70.79572 , ..., 70.756386, 70.75522 ,
            70.75395 ]], 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
    -0.02974 -0.01836 ... 0.02174

    minval :

    -0.39619502

    maxval :

    0.23175192

    array([[-0.02973717, -0.01835657, -0.00985436, ...,  0.067029  ,
             0.06101679,  0.05644643],
           [-0.01926678, -0.00764224,  0.00103568, ...,  0.06844834,
             0.06124458,  0.0560678 ],
           [-0.01059098,  0.00132906,  0.01015474, ...,  0.07419104,
             0.06624249,  0.06069342],
           ...,
           [ 0.0081896 ,  0.00195591, -0.00637672, ...,  0.04312258,
             0.03856932,  0.03566736],
           [ 0.00697589, -0.00089208, -0.01055264, ...,  0.03805647,
             0.03309291,  0.02989119],
           [ 0.01001877, -0.00109449, -0.01357192, ...,  0.0301505 ,
             0.0250091 ,  0.0217437 ]], shape=(2500, 33), dtype=float32)

  • y_sea_water_velocity
    (trajectory, time)
    float32
    0.138 0.1351 ... -0.1145 -0.1147

    minval :

    -0.45612812

    maxval :

    0.2512087

    array([[ 0.13804482,  0.13509636,  0.12821704, ...,  0.07101386,
             0.05164514,  0.04194909],
           [ 0.14678816,  0.14364497,  0.1365713 , ...,  0.0587056 ,
             0.03917932,  0.02950842],
           [ 0.15367705,  0.15045117,  0.14325076, ...,  0.05501014,
             0.03544501,  0.02584241],
           ...,
           [-0.12615056, -0.12187739, -0.11840103, ..., -0.10000994,
            -0.1013611 , -0.10195155],
           [-0.12146781, -0.11589652, -0.10945967, ..., -0.10847677,
            -0.10962595, -0.11007749],
           [-0.11884504, -0.11325881, -0.10545356, ..., -0.11409875,
            -0.11447427, -0.11472976]], shape=(2500, 33), dtype=float32)

  • sea_surface_height
    (trajectory, time)
    float32
    -0.4302 -0.2928 ... 0.07097 0.0391

    minval :

    -1.6726077

    maxval :

    0.19052304

    array([[-0.43024457, -0.29279146, -0.19044298, ..., -0.2933303 ,
            -0.37614483, -0.43111596],
           [-0.4308852 , -0.29319012, -0.1906347 , ..., -0.29297498,
            -0.37578374, -0.43078798],
           [-0.43124107, -0.29340398, -0.19073096, ..., -0.292752  ,
            -0.37553066, -0.43055868],
           ...,
           [-0.36009368, -0.20191157, -0.07949527, ...,  0.11433642,
             0.07741331,  0.04533632],
           [-0.36398423, -0.20564061, -0.08291063, ...,  0.11099541,
             0.07428128,  0.04237846],
           [-0.36774623, -0.20931521, -0.08616286, ...,  0.10765514,
             0.07096702,  0.03909632]], shape=(2500, 33), dtype=float32)

  • x_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... -5.597 -5.665

    minval :

    -11.308028

    maxval :

    0.0

    array([[ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           [ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           [ 0.       ,  0.       ,  0.       , ...,  0.       ,  0.       ,
             0.       ],
           ...,
           [-9.122057 , -9.118852 , -9.359082 , ..., -5.796981 , -5.559577 ,
            -5.5611053],
           [-9.066375 , -8.94957  , -9.179443 , ..., -5.723476 , -5.5612025,
            -5.596461 ],
           [-9.002486 , -8.8197975, -9.037765 , ..., -5.695629 , -5.5969596,
            -5.665215 ]], shape=(2500, 33), dtype=float32)

  • y_wind
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 2.196 1.863 1.707

    minval :

    -2.6664987

    maxval :

    4.690942

    array([[ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           [ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           [ 0.        ,  0.        ,  0.        , ...,  0.        ,
             0.        ,  0.        ],
           ...,
           [-0.7059862 , -0.699673  , -1.0263034 , ...,  2.0602643 ,
             1.7115815 ,  1.5620129 ],
           [-0.7680884 , -0.78505397, -1.0747353 , ...,  2.1292102 ,
             1.773973  ,  1.6143723 ],
           [-0.8771517 , -0.8920562 , -1.1335279 , ...,  2.1958525 ,
             1.8634508 ,  1.7068893 ]], shape=(2500, 33), dtype=float32)

  • upward_sea_water_velocity
    (trajectory, time)
    float32
    0.0 0.0 ... -4.198e-05 -5.339e-05

    minval :

    -0.0029729707

    maxval :

    0.002392182

    array([[ 0.0000000e+00,  0.0000000e+00,  0.0000000e+00, ...,
             0.0000000e+00,  0.0000000e+00,  0.0000000e+00],
           [ 0.0000000e+00,  0.0000000e+00,  0.0000000e+00, ...,
             0.0000000e+00,  0.0000000e+00,  0.0000000e+00],
           [ 0.0000000e+00,  0.0000000e+00,  0.0000000e+00, ...,
             0.0000000e+00,  0.0000000e+00,  0.0000000e+00],
           ...,
           [ 8.3207618e-05,  7.3525858e-05,  6.1422856e-05, ...,
            -1.3584760e-05, -3.3584758e-05, -4.2824977e-05],
           [ 8.3207618e-05,  7.3207615e-05,  5.9811427e-05, ...,
            -1.6980950e-05, -4.1980951e-05, -5.2860014e-05],
           [ 9.3207615e-05,  8.3207618e-05,  6.6415239e-05, ...,
            -1.6980950e-05, -4.1980951e-05, -5.3389824e-05]],
          shape=(2500, 33), dtype=float32)

  • sea_surface_wave_significant_height
    (trajectory, time)
    float32
    0.0 0.0 0.0 ... 0.9166 0.856 0.8612

    minval :

    0.0

    maxval :

    3.1471353

    array([[0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           [0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           [0.        , 0.        , 0.        , ..., 0.        , 0.        ,
            0.        ],
           ...,
           [2.059274  , 2.0576177 , 2.1806848 , ..., 0.93110204, 0.83242464,
            0.820798  ],
           [2.036612  , 1.9854933 , 2.101264  , ..., 0.91737604, 0.83821917,
            0.8345937 ],
           [2.012628  , 1.9331808 , 2.0409658 , ..., 0.91664416, 0.8560407 ,
            0.86120003]], 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 ... 2.942e+03

    minval :

    2890.3042

    maxval :

    3240.8923

    array([[3237.6443, 3237.6597, 3237.6187, ..., 3237.1714, 3236.708 ,
            3236.506 ],
           [3231.7302, 3231.6958, 3231.6108, ..., 3231.0042, 3230.608 ,
            3230.4385],
           [3226.837 , 3226.7944, 3226.704 , ..., 3225.5757, 3225.268 ,
            3225.1375],
           ...,
           [2909.3318, 2910.7446, 2912.1162, ..., 2967.545 , 2968.1023,
            2968.3662],
           [2900.6626, 2902.2961, 2903.9475, ..., 2955.2695, 2956.6543,
            2957.3623],
           [2890.7188, 2892.423 , 2894.1616, ..., 2939.668 , 2941.0527,
            2941.779 ]], 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(['2025-12-05 09:20:22.628439', '2025-12-05 09:50:22.628439',
                   '2025-12-05 10:20:22.628439', '2025-12-05 10:50:22.628439',
                   '2025-12-05 11:20:22.628439', '2025-12-05 11:50:22.628439',
                   '2025-12-05 12:20:22.628439', '2025-12-05 12:50:22.628439',
                   '2025-12-05 13:20:22.628439', '2025-12-05 13:50:22.628439',
                   '2025-12-05 14:20:22.628439', '2025-12-05 14:50:22.628439',
                   '2025-12-05 15:20:22.628439', '2025-12-05 15:50:22.628439',
                   '2025-12-05 16:20:22.628439', '2025-12-05 16:50:22.628439',
                   '2025-12-05 17:20:22.628439', '2025-12-05 17:50:22.628439',
                   '2025-12-05 18:20:22.628439', '2025-12-05 18:50:22.628439',
                   '2025-12-05 19:20:22.628439', '2025-12-05 19:50:22.628439',
                   '2025-12-05 20:20:22.628439', '2025-12-05 20:50:22.628439',
                   '2025-12-05 21:20:22.628439', '2025-12-05 21:50:22.628439',
                   '2025-12-05 22:20:22.628439', '2025-12-05 22:50:22.628439',
                   '2025-12-05 23:20:22.628439', '2025-12-05 23:50:22.628439',
                   '2025-12-06 00:20:22.628439', '2025-12-06 00:50:22.628439',
                   '2025-12-06 01:20:22.628439'],
                  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 2025-12-05 09:20:27.451626

  date_created :

  2025-12-05T09:20:27.451639

  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 :

  2025-12-05 09:20:22.628439

  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 :

  2025-12-05 09:20:27.458819

  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 :

  2025-12-06 01:20:22.628439

  time_coverage_duration :

  P0DT16H0M0S

  time_coverage_resolution :

  P0DT0H15M0S

  performance :

  -------------------- Reader performance: -------------------- https://thredds.met.no/thredds/dodsC/fou-hi/norkystv3_800m_m00_be 0:00:32.8 total 0:00:00.0 preparing 0:00:32.4 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 0:00:44.3 total 0:00:00.0 preparing 0:00:44.1 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: 1:26.9 total time 8.0 configuration 0.0 preparing main loop 0.0 moving elements to ocean 1:18.9 main loop 0.2 updating elements 0.0 cleaning up --------------------

  geospatial_bounds_crs :

  EPSG:4326

  geospatial_bounds_vertical_crs :

  EPSG:5831

  geospatial_lat_min :

  69.77808

  geospatial_lat_max :

  70.85056

  geospatial_lat_units :

  degrees_north

  geospatial_lat_resolution :

  point

  geospatial_lon_min :

  4.871834

  geospatial_lon_max :

  8.0

  geospatial_lon_units :

  degrees_east

  geospatial_lon_resolution :

  point

  runtime :

  0:01:26.981392

  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
 0:00:32.8  total
 0:00:00.0  preparing
 0:00:32.4  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
 0:00:44.3  total
 0:00:00.0  preparing
 0:00:44.1  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:
 1:26.9 total time
    8.0 configuration
    0.0 preparing main loop
      0.0 moving elements to ocean
 1:18.9 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: 2025-12-05 09:20:22.628439 UTC
        Present: 2025-12-06 01:20:22.628439 UTC
        Calculation steps: 64 * 0:15:00 - total time: 16:00:00
        Output steps: 33 * 0:30:00
===========================

09:21:46 WARNING opendrift:2473: Plotting fast. This will make your plots less accurate.
09:21:47 INFO    opendrift:4656: Saving animation to /root/project/docs/source/gallery/animations/example_reader_boundary_0.gif...
09:22:10 INFO    opendrift:3091: Time to make animation: 0:00:23.790026

o.plot(fast=True)

09:22:10 WARNING opendrift:2473: Plotting fast. This will make your plots less accurate.

(<GeoAxes: title={'center': 'OpenDrift - OceanDrift\n2025-12-05 09:20 to 2025-12-06 01:20 UTC (33 steps)'}>, <Figure size 922.265x1100 with 1 Axes>)