Lagrangian trajectories representing surface drift from the Cape Verde islands

Example trajectories from a biophysical Lagrangian simulation

This is 25x 50.000 example trajectories from biophysical experiments performed with Parcels.

The trajectories are a tiny subset of a much bigger collection of trajectories that have been simulated with the aim of learning about the fate of particles drifting away from the Cape Verde islands.

Note, that these trajectories should not be used for biological or physical science but merely serve as study objects for developing, testing, or benchmarking (stasticical) methods and algorithms.

Details of the experiments

The trajectories are taken from 25 sets of biophysical simulations which differ in the year they represent. Particles are seeded between mid of August and start of December of the years 1993 to 2017. They are subject to Ocean surface currents simulated by a high-resolution ocean model and subject to Stokes Drift estimated by a wave simulation data provided by the Copernicus Marine Service (https://marine.copernicus.eu/).

Data

• The full data come as a Zarr store inside of a ZIP file cape_verde_drift_trajectories_1993-2017.zarr.zip which you need to download and unzip to be able to read it, e.g., with Xarray's open_zarr method.
• There are subsets of 10000 trajectories provided as compressed csv files split into years called cape_verde_drift_trajectories_1-10000_1993.csv.gz ... cape_verde_drift_trajectories_1-10000_2017.csv.gz.
• And there are subsets of 100 trajectories provided as un-compressed csv files split into years called cape_verde_drift_trajectories_1-100_1993.csv ... cape_verde_drift_trajectories_1-100_2017.csv.

Variables and their meaning

• "obs" contains the time step since the larva started to exist. Each trajectory covers up to 881 daily positions.

• "traj" indicates the trajectory ID.

• "lat" and "lon" contain the horizontal positions in degrees Latitude and Longitude.

• "temp" contains the ambient temperature in degrees Celsius the simulated larva would have felt.

• "time" contains time stamps for each position.

• "z" contains the vertical positions of the simulated larva in meters counted downwards. As "z" does not vary (all particles are at the surface), it is omitted from the CSV files.

Using the data

This data set is licensed under a Creative Commons Attribution 4.0 International License.

If you use the data, we'd love to get a notice to wrath@geomar.de. This is, however, not required.