Glider sustained observations in the Mediterranean

Testor P., Heslop E., Gana S., A. Bosse, Hayes D., Ait-Ameur N., Budillon G., Gildor H., Iudicone D., Mauri E., Mortier L., Petihakis G., J. Tintore

et al.

The Economist, 2012/06/09

1km

~2-5km / ~4h

Data Centers

Land Station

Users

Glider facilities

Gliders

Physical and biogeochemical sensors on board(a ‘profile’ in 0.5-5 h ~ 0.5-5km)

+ depth-average currents (GPS + dead reckoning)

U ~ 25 km/day (~ 0.5 knot)Small & smart

Pot. TempSalinityPot. Dens.OxygenFluo ChlaTurbiditynorth south

NorthernCurrent

North Balearic

Front

Mixed patch

Gliders: • Reveal a wide range of variability (smallbasin scales) • Are present at sea even during strong weather conditions• Allow to study the physical-biogeochemical coupling

A vertical section from a glider:

eddiesPlumes ~1km

Multidisciplinary data

10 years of gliders in the Mediterranean

2004/09 2005/09: EU: MFSTEP and creation of the EGO network2005/09 2006/09: EU: MFSTEP, MERSEA2006/09 2007/09: EU: MERSEA national projects: ES, FR, UK (spin-off of EU projects)

2007/09 2008/09: EU: MERSEA national projects: ES, FR, UK

2008/09 2009/09: national projects: CY, ES, IT, FRbeginning of long term monitoring initiatives (CY, ES, FR)

2009/09 2010/09: EU: EGO COST Action national projects: CY, ES, IT, FR

2010/09 2011/09: EU: GROOM, JERICO / EGO COST Action national projects: CY, ES, FR

2011/09 2012/09: EU: PERSEUS, GROOM, JERICO / EGO COST Action national projects: CY, ES, FR

2012/09 2013/09: EU: PERSEUS, GROOM, JERICO / EGO COST Action national projects: CY, ES, FR, IT

2013/09 now: EU: PERSEUS, GROOM, JERICO / EGO COST Actionnational projects: CY, ES, FR, IT, DZ, TN,

10 years of gliders in the Mediterranean

2004/09 now: > 40 000 profiles of Temp, Sal, Chl-a, O2,Turb,…>10 000 estimates of average currents

All glider data

Gliders in the Mediterranean

• Glider observations have been sustained in 3 areas of the Med.

• Demonstrations elsewhere and in particular: the Algerian basin in the framework of JERICO TNA (MUSICS and ABACCUS projects) = identified gap by PERSEUS

• Momentum: plans for new gliderports and sustained observations (IL, IT, GR,…)

• The number of profiles of T, S, Chla, O2, Turb,… and average currents estimates provides now new knowledge of the oceanic variability in the Med.

• In the following: examples of the glider added value in the 3 sustained observations areas, in the context of global changes

important to monitor the ocean but difficult to really assess the heat content

CYCOFOS

MOOSE

SOCIB

2014: all Temperature profiles

Nb of profiles per year in the NWMED

profiling floats glidersshipsXBTs/XCTDs

… before the gliders era

Example of the northwestern Mediterranean

At depth: small variability (~0.1degC) low (small) frequency signals can emerge

But above: larger variability, strong need of much more observations to reduce uncertainties

We know the temperature of deep waters (>700m) is increasing since the 70s,

But no similar assessment could be made for the surface and intermediate layers…

Pot. Temp (>700m)

Variability/trends in the northwestern Mediterranean Sea

Surface and intermediate layers in the Ligurian Sea

Contrasts between the open ocean (brown/yellow) and the coast (green/Villefranche and blue/Corsica) indicators of dynamical regimes (full line = significant and not aliased)

2010 2014201320122011200920082007

AW temperature

AW salinity

LIW temperature

LIW salinity

2010 2014201320122011200920082007

Seasonal cycles

Abrupt changes / reversals

Interannual variability

Variability/trends in the northwestern Mediterranean Sea

Surface and intermediate layers in the Golf of Lion

Contrasts between the open ocean (brown/yellow) and the coast (pink/Toulon, orange/Marseille, purple/Banyuls) indicators of dynamical regimes (full line = significant and not aliased)

2010 2014201320122011200920082007

AW temperature

AW salinity

LIW temperature

2010 2014201320122011200920082007

LIW salinity

Seasonal cycles

Abrupt changes / reversals

Interannual variability

Variability/trends in the Eastern Mediterranean

salinity

temperature

at depth of 29 sigma0

Shift in temperature and salinity in 2009Recovery to previous values since 2012.Possibly:

• LIW formed differently in different years or in multiple locations• Atmospheric conditions and/or surface properties have changed

Implications on heat/salt budgets of the Med and processes that involve LIW

Variability/trends in the Ibiza channel

• Long timeseries at high frequency• Climatology: Seasonal variability in transports throught the Ibiza Channel

TALK: Heslop E., Tintore J., Poulain P., Lopez-Jurado J-L. & Torner M.: The ‘quiet revolution’: continuous glider monitoring at ocean ‘choke’ points as key component of an EU cross-platform ocean observation strategy

New components: MUSICS and ABACUS

- Hydrography along altimetry tracks- Biogeochemical data- Strait transports- Eddy hunting- Large/meso/submeso scale features

ABACUS: 31/08 -04/09 ;15/09-30/10; 20/11 now

MUSICS: 16/08-23/09

TALK: Gana S., Iudicone D., Ghenim L., Mortier L., Testor P., Olita A., Nardelli B. & Tintore J. : Multi-Sensor Investigation in the Channel Of Sardinia (MuSiCs)

To be sustained ! (observing systems: SOMBA/SOCIB)

Towards a Mediterranean glider network (prospects)

Integrated and sustained in complement with the other observing systems

prospects

2013-2014 repeat sections

Conclusions

• 10 years of gliders in the Mediterranean Sea have changed the way we can characterize the oceanic variability. Constant presence at sea is possible and a wide range of scales can now be resolved (avoid aliasing).

• New knowledge for hydrography and currents. Reliable indicators can now be built ! Work in progress for biogeochemistry (O2, Chl-a, Turbidity)

• The glider network is expanding in order to fill gaps thanks to PERSEUS WP3 actions.

• Gliders = platforms with on board sensors. The scientific bay is evolving fast. The present portfolio is (T, S, O2, fluorescence Chl-a, fluorescence CDOM, fluorescence Phycoerythrin, Turbidity) but tests with nitrate, ph/pCo2 hydrocarbons sensors, passive/active acoustics have been carried out. Water samples and video are planned too.

Vast field of usages in the framework of MSFD

Real time data can be assimilated in numerical models (Earth observation, Copernicus)