Presentation of the tools developed (part 1)

2. Presentation of the tools developed (part 1)

3. Presentation of the tools developed (part 1) • How to optimize the drifters deployment strategy? • -> Enrico ZAMBIANCHI, DISAM

5. 2 different issues • Large scale flow (several info sources) • Small scale flow (almost only drifters)

6. Large-scale flow • No info ≤ Ro ~ 5 km for coastal Mediterranean areas [Ro is the typical scale of eddies and mesoscale flow features]

7. Large-scale flow • How can wegain some info?

8. Large-scale flow • Some prior (or current) knowledgemaybeextremelyuseful, • or evencrucial…

9. Large-scale flow

10. Large-scale flow • but…

11. Large-scale flow • but…

12. Large-scale flow • Some priorknowledgemaybeextremelyuseful, or evencrucial…

13. Large-scale flow • Some priorknowledgemaybeextremelyuseful, or evencrucial…

14. Large-scale flow • Prior/current knowledge possible sources (need for synopticity) • ad hoc drifter deployments • past observations of repetitive patterns • knowledge of specific dynamical situations (fronts, LCSs) • HF radar data

15. Large-scale flow • Redeployment is highly recommended

16. Large-scale flow • Redeployment is highly recommended

17. Large-scale flow • Forecast possible sources: • persistence + LAVA • models… • non assimilatingHF radar or othertypesof data (velocitypreferred) • assimilating HF radar or other types of data (velocity preferred)

18. LS flow - Recommendations • Prior or initial knowledge required – if missing, plan individual deployments to get an idea of LS flow • Distance between deployments ≤ Ro (~ 4-5 km) • Deployments on a regular grid, if necessary adapted to specific flow patterns/regimes (fronts, eddies, connecting paths) • If constrained by budget and/or logistics, spare drifters in order to redeploy

19. LS flow – add’l recommend • If you have people running a model or collecting synoptic data, ASK THEM (the Ro rule of thumb stands anyway) By-recommendation: study your areas as intensively as you can, install as many radar systems as you can, get yourself a good forecast model…

20. LS flow: one special issue • In coastal areas several “interesting” features may occur: Lagrangian Coherent Structures are barriers to transport, created by the velocity field. They separate neighbouring sub-areas of a basin which do not exchange fluid with each other, thus limiting the effectiveness of water renewal processes. (the first LCS-targeted massive drifter experiment ever was organized within TOSCA)

21. Small-scale flow • Small-scale = subgrid scale, • controls the spreading

22. Relative dispersion Are sub-mesoscale processes (i.e. processes at scales less than Ro) important? Relative dispersion measures the separation between pairs of particles

23. Naples , Toulon and Trieste deploymentstrategies Relative = particle pair separation 50 m 50 m 50 m

25. SS flow - Recommendation Along with the deployments planned for the Large-Scale flow deploy triplets! anywhere in the field, and in particular if there are fronts or other interesting structures

26. Thanks for attending TOSCA Final Meeting!