Monitoring trans-boundary maritime space with autonomous...

Monitoring trans-boundary maritime space with autonomous systems:

drifters, floats and gliders

P.-M. PoulainIstituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS)

Trieste, Italy

Talk Outline

Mobile Autonomous Oceanographic Instruments: Drifters, Floats and Gliders

Selected Mediterranean Applications

Contribution to CALYPSO

CALYPSO Seminar, 28 May 2012, La Valletta, MaltaCALYPSO Seminar, 28 May 2012, La Valletta, MaltaCALYPSO Seminar, 28 May 2012, La Valletta, MaltaCALYPSO Seminar, 28 May 2012, La Valletta, Malta

Mobile Autonomous Oceanographic Instruments: Drifters

CODE-type Designs

CALYPSO Seminar, 28 May 2012, La Valletta, Malta

SVP-type Designs



Oil-spill Designs



Low-cost (1-5 K€) & generally expendable

Tracking and data telemetry (Argos, GPS, Iridium, GSM)

Data:

• Near surface currents (0, 15, 50 m) from successive positions• SST, T(z), SSS• Optical parameters (Lu, Ed)• Air temperature & atmospheric pressure• Wind speed & direction

NRT processing and dissemination (sampling period of 0.5-2 h)

Characteristics



Deployments


From Research Vessels

From Volunteer Observing Ships (VOS)


Composite Track Diagram (1985-2011)



~1300 drifters258 drifter-years in 25 years = 10 drifter-years per year

Profiling instruments

Provor Apex

Sea-Bird CTD5,10,…,100,110,…,

700,750,…,2000 dbar

Satellite Argos Antenna

Bladder

Mobile Autonomous Oceanographic Instruments: Floats


Sampling Characteristics

NRT data (every 5 or 10 days):

Pressure, temperature, conductivity (salinity)Oxygen, chlorophyll, turbidity, etc.

Medium cost (15-20 K€) Long-lived (> 3 years)Generally expandable

Argos or Iridium data telemetry



Deployments

R/V and SOP



CTD Profiles (2001-2011)

122 floats



Autonomous Gliding vehicles

Spray

Scripps

Institution of

Oceanography

Seaglider

APL-University of

Washington

Slocum

Webb Research

Corp.


Mobile Autonomous Oceanographic Instruments: Gliders

1) Gliders are driven by

positive and negative

buoyancy created by

a change in volume.

No propeller is

required.

2) Wings convert

vertical velocity into

forward velocity.

3) To change the

direction of the glider

a rudder is used or

internal mass is

rotated.

4) Glider move

downward and

upward in a

sawtooth pattern

Sampling Characteristics

U ~ 20-40 cm/s

W ~ 10-20cm/s

1 km or 200 m

~2-5 km between surfacings



Communication & SensorsArgos, Iridium, VHF link

Sea-Bird CTD

PingerOptics

O2

NRT data (every surfacing):

Pressure, temperature, conductivity (salinity)Oxygen, chlorophyll,

turbidity, etc.

High cost (100-150 K€)

Not expendable!



Selected Mediterranean Applications:Circulation in the Strait of Sicily (1990-1999)

Poulain and Zambianchi (CSR, 2007)


Monitoring surface circulation with drifters

Mean Circulation Variability




Monitoring surface circulation with drifters

Anti-MistralMistral

Wind-induced Variations of Mean Circulation




Selected Mediterranean Applications: Gulf of La Spezia (POET)

Surface circulation & dispersion from drifters and HF radars

Experiment Deployment Recovery No of drifters

1 18 June 07 / 14:10 19 June 07 / 10:50 5

2 20 June 07 / 08:40 21 June 07 / 10:33 6

3 22 June 07 / 10:23 25 June 07 / 03:58 3

4 22 June 07 / 12:47 23 June 07 / 04:16 4

5 25 June 07 / 17:54 26 June 07 / 10:33 3


Molcard et al. (JMS, 2009)

Selected Mediterranean Applications: Gulf of La Spezia (POET)

Surface circulation & dispersion from drifters and HF radars


RMS difference ~ 5 cm/s

An Arvor-C float was deployed on 10 October 2011 and provided temperature and salinity profiles every 3 h until 24 October 2011.

In total, the float executed 136 CTD profiles between the surface (0 m) and a maximal depth of about 400 m.

T/S profiles (10-24 Oct 2011)

Selected Mediterranean Applications: Tuscan Archipelago (MILONGA)


T/S profiles (10-24 Oct 2011)

Selected Mediterranean Applications: Tuscan Archipelago (MILONGA)


Selected Mediterranean Applications: South of Cyprus (Eye of the Levantine, Dec 2009)




Satellite-derived dynamic topography and drifters (Nov 2009)



Glider tracks and near-surface currents

Contribution to CALYPSO:

Deployments of surface drifters in HF radar domain to complement/validate current measurements : four seasonal deployment of 5 drifters


Drifters and floats to monitor surface currents and profiles of temperature and salinity in the Malta Channel

Deployment of an Argo float (Arvor with Iridium telemetry) to measure profiles of temperature and salinity at daily intervals (also useful to validate, or to be assimilated in, regional numerical models)

Thank you for your attention, any questions?

Monitoring trans-boundary maritime space with autonomous...

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