Digital Twin Currents release

Currents for the Digital Twin North Sea

Goal

This dataset and the corresponding application programming interface (API)
provides current fields for the Digital Twin North Sea.

Different purposes require different currents. Common usages include:

• Optimizing shipping routes, finding the shortest path. This requires realtime currents on the surface.
• Ecological model, transport of plankton. Requires currents, typically in the upper regions, but sometimes near the bottom, averaged over a period.
• Search and rescue, finding people lost at sea. This requires currents near the surface, unless people are deceased then they can float in different locations in the water column, a day ahead.
• Drifter studies, tracking transport of particles, such as plastics. Typically requires surface currents over the period of several days, weeks or months.

Here we focus on the Ecological use. The current fields are intended
for use in the ecopath/ecosim simulations in the Marine Spatial Planning Tool component.

Features

We provide a number of features in our currents api.

• Density currents on top layer of the ocean based on the HYCOM model
• Tidal and wind driven currents based on an archive of the GLOSSIS operational system
• Selection by bounding box (default North Sea)
• Custom scale (default 10km)

Example currents from the HYCOM Ocean model. Note the density currents near the Norwegian coast. Hue represent direction. Intensity represents velocity (0-1m/s).

Example currents from the GLOSSIS Coastal model. Note the tidal currents that circle around the UK. Hue represent direction. Intensity represents velocity (0-1m/s).

Methods

To determine the current fields we use the following workflow:

• define the region of interest (North Sea)
• define the scale of interest (10km)
• define the coordinate system (EPSG:3505)
• define the timespan of interest (2020-07-01 -- 2021-07-01)
• determine the months in the timespan of interest
• for each month:
• compute monthly mean current velocity u, v field
• for HYCOM choose the top layer (level 0)
• rescale the current field to the region of interest at the requested scale.
• store the results in a google cloud bucket

Roadmap

Features that we are planning to extend include:

• API process result implementation- Selection by time period (pending processing of the Global Tide and Surge Model, the reanalysis version of GLOSSIS)
• Custom coordinate system (removed from geojson)

Screenshots

The following screenshots provide some example results of the current fields:

Usage/Examples

curl --location --request POST 'https://hydro-engine.ey.r.appspot.com/compute_current_fields' \
--header 'Content-Type: application/json' \
--data-raw '{
      "type": "Feature",
      "properties": {
          "tStart": "2020-07-01",
          "tStop": "2021-07-01",
          "scale": 10000,
          "model": "HYCOM"
      },
      "geometry": {
        "type": "Polygon",
        "coordinates": [
          [
            [
              -3.515625,
              50.261253827584724
            ],
            [
              8.876953125,
              50.261253827584724
            ],
            [
              8.876953125,
              57.136239319177434
            ],
            [
              -3.515625,
              57.136239319177434
            ],
            [
              -3.515625,
              50.261253827584724
            ]
          ]
        ]
      }
    }'

Deployment

This service is deployed on the following url:

https://hydro-engine.appspot.com/

The Google Earth Engine code for the current calculations can be found in the Google Earth Engine code editor.

API Reference

Get all items

  POST /compute_current_fields

Parameter	Type	Description
POST body	application/json	Required. GeoJSON feature, see details below

Parameter	Type	Description
geometry	object	Required. Polygon with the area of interest
properties	object	Required. Object with the following properties listed below

Parameter	Type	Description
model	string	Required. 'HYCOM' or 'GLOSSIS'
scale	Number	default: 10000. Scale at which output is generated [m]
tStart	string	default: first of current month - 1 year. Start time [iso date format]
tStop	string	default: first of current month. End time [iso date format]

License

GPLv3

Wind farm update

Inclusion of wind farm power model.

Liwo build release

Merge pull request #14 from openearth/fix/bands

fix(scale): remove log scales