Round table session #2: PS2b

Round table session #2: PS2bPS2b

PS2b aims at better defining : TT04 : Sounding the ocean Partially TTO5 : Measuring air-sea fluxes Partially TTO6 : Measuring land-sea fluxes

Main objectives : Define the instruments that need to be deployed in

sites/supersites or the research platforms needed For each instrument/platform :

Describe the scientific aims Describe how it includes in the overall program strategy Identify the groups/persons in charge of deployment

Establish a priority list Gather information about funding collected

Discussion about the SOP HYMEReX (30 mn)

Scientific issues

(Sub-) Méso-scale eddies Oceanic deep convection OA boundary layer heat budgets Ocean mixed layer salt budget Water masses circulation ...

Oceanic deep convection

Needs : Network of CTD profiles (SOP, EOP) Time-series of CTD profiles (moored mode) completed in

the upper layer by CTDs under a surface buoy (SOP-EOP-LOP)

Dedicated CTDs transects : chimney (SOP), cross-basin (EOP/LOP)

Autonomous float measuring the vertical velocities : Pegasus float, Gascard stuff, gliders in mooring mode ? + moored fixed current profilers (ADCP)

Time series of deep moored CTDs (LOP, Hydrochanges) Time series of SST/SSS along transects from ships of

opportunity + XBTs (MOON-MyOcean contribution) ARGO profilers (+ wider applications) (EOP, LOP)

Oceanic deep convection

(°C)

S

(kg.m-3)

~12.89

~ 38.49

> 29.12

2007 2008

~ 12.87

~ 38.48

< 29.12

CENTRE OF CONVECTION ZONE (42°N 5°E)2300 m

2- 2333m

3- 2468m

4- 2218m

5- 2473m

6- 2362m

7- 2473m

Variations/variabilité de la température qqm au dessus du fond !

Apr. 06 Mar. 07

0.1°C

0.1°C

0.1°C

0.1°C

0.1°C

0.1°C

OA boundary layer heat budgets

Needs : ~20 marisondes (drifting buoys equipped with

thermistors chain (SOP) Moored surface buoys (SOP, EOP, LOP ?)

TurbulentTurbulent heat fluxes estimated using bulk formulae together with meteo-oceanic parameters (wind speed, T, Hu, SLP, SST)

RadiativeRadiative heat fluxes (longwave, shortwave)

Shipborne mast (SOP, EOP/LOP on SOO) TurbulentTurbulent heat fluxes deduced from turbulence measurements

(IDM, ECM) RadiativeRadiative heat fluxes (longwave, shortwave)

XBTs/UCTD transects (heavy rain events)

OA boundary layer heat budgets(heavy rain events)

XBTs, U-CTDs

OA boundary layer heat budgets(TRANSMED potential network)

Ocean mixed layer salt budget

Needs : SVP-BS : drifting buoys equipped with

thermistors, Barometer and Salinity (SOP, EOP) On moored buoys: CTD measurements +100s m

(SOP, EOP)

Water masses circulation

Needs : Currentmeter moorings in the DWF (SOP) Deep moored CTDs (increase the number of

moorings, esp: E. Balearic, Sardinia, ..., Eastern Basin) (SOP, EOP, LOP)

Periodic (~1/year) CTD transects (down to the bottom)

Water masses circulationCTD transects, ~1/year

?

(Sub-) Méso-scale eddies

Document the (sub-) meso-scale eddies in order to quantify their role in the subduction of water masses (below the mixed layer)

Needs : Tow-yo (seasoar, U-CTD) T/S transects (SOP)

HYMEReX network (SOP)

closure area stations (31)

network stations (249)

--- 200m

--- 1000m

Sudden increase of and S in late January 2005

Drop in early March 2005, a few days after intensification of shelf-cascading reported by (Canals et al, 2006)

New stable characteristicsabove the initial ones

Font J., Puig P., Salat J., Palanques A. and Emelianov M., 2007. Sequence of changes in the NW Mediterranean deep water due to the exceptional winter 2005.

Sci. Mar., 71(2), 339-346.