Action ES0904European Gliding Observatories Network (EGO) Final Symposium

Simón Ruiz (Spain)

Daniel Hayes (Cyprus)WG5 leaders

Kiel, 16-17June 2014

Outline

• Objectives WG5.

• Tasks.

• Endurance lines and glider fleets experiments.

• Glider data analysis and merging.

• Gliders and modelling.

• Summary.

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Scope WG5 - Action ES0904

This WG focus on the way to conduct fields operations with fleets of gliders to gather detailed and accurate 4D oceanic data sets related to different specific research requirements. Of particular interest here are the large trans-oceanic sections (such as RAPID section) or boundary current sections (often referred as “Endurance lines”) for large scale or regional budgets as well as the investigation of mesoscale and submesoscale phenomena in specific areas. This task will use the piloting facilities developed by WG3, including adaptive sampling techniques together with associated data analysis tools. Part of this work will be done in cooperation with the community of operational modelling that will provide both the forecasts to assess the distribution of glider over the sections or shape of the fleet to cover as well as the modelling platforms themselves in order to perform detailed post processing of the collected data.

Proposed deliverables:

-Glider fleet field campaigns methodologies and reports on the performed campaigns. -Development and tests of data analysis tools for registering and fusing data gathered from multiple gliders with other source of data.

-Assessment on techniques (including data assimilation into operational systems) for retrieval of 4-D oceanic parameters from high resolutions surveys for physical and biogeochemical parameters.

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Endurance lines

Balearic Channels – Western Mediterranean

RAPID program – 26ºN Canary Islands

Fram Strait program – North Atlantic

MOOSE program – Northwestern Mediterranean

Nice

CalviMenorca

Mallorca

Fuerteventura

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Red dots show the location of gliderprofiles starting from deployment of the coast of Gran Canaria, followedby transit to the operation site on the 1000m contour off Morocco. Magenta crosses indicate the locations of the RAPID moorings.

Endurance lines: case 1 Rapid program

Dynamic height difference between 200m and 800m: gray = from glider before removal of internal tide; black = de-tided glider data

magenta = corresponding values from mooring (40-hour low pass filtered). The yellow shows the dynamic height difference 10m to 110m from glider data.

Smeed & Wright (2009)

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Endurance lines: case 2 Ibiza Channel

Heslop et al., 2012, GRL

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Nice

Calvi

Menorca

Endurance lines: case 3 Northwestern Med

Piterbarg et al., 2014, JMS

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Endurance lines: case 4 Fram Strait program

(Beszczynska-Möller et al., 2012)

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Fleet of glidersSWARM experiment From September 2012 until May 2013

(GROOM, JERICO TNA, PERSEUS, NOMR12, MISTRALS, MOOSE)

- 8 gliders- (Sub)-mesoscale process - Transports- Deep convection- Modelling

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Glider fleet camapaingsTropical waters

SWARM01 experimentnear Cabo Verde Islands

March, 20106 glidersTemporal variability of physical andbiogeochemical parameters

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Glider fleet campaings

EYE Experiment

WARM CORE CYPRUS EDDY

December 2012

6 gliders2 profiling floats4 surface drifterShipborne measurements

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Data analysis and fusing data

Gliders for ocean processes oriented studies:

• Merging glider data with altimetry / Argo / moorings.• Boundary currents, tranports and sub-mesoscale processes.• Vertical velocities estimation.• Ocean mixing/convection and impact on heat content and biogeochemistry.• Upwelling.• Sediment fluxes.• Model validation / assimilation.• Water properties around submarine vulcano subtropical waters.• Coastal waves• Frontal variabiality• Polar regions• …..

More than 50 SCI papers

Exhaustive list of references can be found at:http://www.ego-network.org/dokuwiki/doku.php?id=public:references

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Data analysis and fusing data: Examples Surface plot of temperature and salinity in the basin site (LION) between 1 December 2011 and 1 June 2012

Durrieu de Madron et al., GRL, 2013

Cascading and deep convection

Durrieu de Madron et al., GRL, 2013

Cascading and deep convection

Vertical section of temperature (a,b),density (c,d), and B-V (e,f)

Ruiz et al., GRL, 2012

Upper ocean mixing

Ruiz et al., GRL, 2012

Upper ocean mixing

Oxygen section concentration 2–23 December 2007. Isopycnals are drawn in gray

Ullgren et al., JGR, 2013

Water interactions

Ullgren et al., JGR, 2013

Water interactions

Temperature distribution in the upper 12m (a, b) potential energy of the upper 10m (c, d) , vertical integrated velocity from glider (e, f) ,

Karstensen et al., 2014,

Biogeosc., Summer Upwelling

Karstensen et al., 2014,

Biogeosc., Summer Upwelling

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Gliders and modelling

Averaged fields between glider assimilation (left) and control (right) analyses on 23 December 2004

Dobricic et al., 2010, Dyn. Atm. and Oce.

Glider data assimilation

Dobricic et al., 2010, Dyn. Atm. and Oce.

Glider data assimilation

Mourre and Alvarez, 2012, Ocea. Dyn. Super-ensamble multi modellling

Mourre and Alvarez, 2012, Ocea. Dyn. Super-ensamble multi modellling

3DSE temperature forecast at 80-meter depth produced on29 August 2010 and valid for 1 September 00:00 (t0+72 h).Right: associated uncertainty (yellow squares display theposition of assimilated observations at this depth)

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Summary - Gliders represent a revolution for the characterization of mesoscale and sub-mesoscale ocean processes.

- Gliders data can be merged with data from other platforms (moorings, Argo, Altimetry) to complement the view of the 3D state of the ocean.

- Endurance lines: Gliders are useful in shelf areas where other platforms such as Argo are rare or ship sampling can not be mantained regularly.

- Fleet campaings: Successful field experiments in the Atlantic, Pacific ocean and in the Mediterraean Sea.

- Useful for modelling (validation and data assimilation).

Thank you

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Data analysis and fusing

Methodology to combine glider and altimetry

To obtain a 3D field, the method combines: - The vertical modes of DH from glider (vertical dependent) - The gridded altimetry data (x,y)

)(),()( 11, pEOFyxApyx

In the case of a single dominant mode, the modelled profile can be expressed as:

Altimetry glider

For diagnosing vertical velocities (Omega-equation) we need a 3D DH field. Method for reconstruction (JAOT, Pascual and Gomis, 2003)

Thus, obtaining the single amplitude corresponding to each profile A1(x, y) would be straightforward given the surface altimetry data and the surface component of theleading EOF [EOF1(p0)] from glider data.

Reconstructed field

Dynamic height (cm)

Solid: original profileDashed: reconstructed

Dynamic height (cm)

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Glider fleet campaings:

Case 1 : REP13 experiment

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Glider fleet campaings:

Case 1 : REP13 experiment