development of the glider system in-situ observations mersea 3rd annual meeting london, 06.03.2006...

Development of the glider system

In-Situ Observations

MERSEA 3rd annual meetingLondon, 06.03.2006

IFM-GEOMAR, Kiel, GermanyIMEDEA, Esporles, Spain

IFREMER, LPO, Coriolis, CERSAT, Brest, France,LOCEAN, Paris, France,

MERCATOR, Toulouse, FranceSIO, LaJolla, CA, USA

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) Glide downward when denser than surrounding water and upward when buoyant, in a sawtooth pattern.

SprayScripps Institution of Oceanography

SeagliderAPL-University of

Washington

Slocum Webb Research

Corp.

Autonomous Underwater Gliding Vehicle (AUGVs): GLIDERS

change of buoyancy and control ofinternal mass distribution

forward movements

induced vertical velocity,and control of roll and pitch

Coriolis Data CenterIFREMERBrest, France

Numerical ModelsMercator, MFS, ...

Ground StationIFM-GEOMAR

Kiel, Germany

U ~ 20-40 cm/sW ~ 10-20cm/s

Autonomous Underwater Gliding Vehicle (AUGVs): GLIDERS

1km

~2-5 km between surfacings

North Atlantic Ocean

Mediterranean Sea

Development of the glider system:

Collection of Physical and Biogeochemical Data during the TOP phase

Data Flow and Quality Control

Data Assimilation

Next operations

Spray gliderScripps Institution of Oceanography

Slocum glider Webb Research Corporation

MERSEA gliders

WP3.5: assessment of available long-range glider technologies which meet MERSEA requirements

Mediterranean Sea

Operations with 2 Slocums

1) Development of user-fitted lithium batteriesfor better endurance (x3)Tests during a “virtual mooring“ mission.

~120 profiles (0-1000m, end of Sept. 2005)

2) Trials in coastal environment (0-200m)

Poster WP3.5

Virtual mooring off Mallorca

21.09.2005 02.10.2005To be continued...

Potential temperature

North Atlantic Ocean – TOP phase

Glider survey around PAP (MERSEA multidisciplinary mooring)

Press releases for MERSEAOuest-France Telegramme

Proven ~3-months endurance (> 2300 km horiz.)

Carried out ~450 dives to 1000mmeasurements of

- Salinity,- Temperature,- Fluorescence (Chl), - Currents averaged

over 0-1000m (green arrows).

Preparation at Ifremer (Brest)

Deployment from the Argonaute (SHOM) on the 05.12.2005 - still active!

+

All profiles in grey. Last profiles in color. [n=last profile]


5 Dec. 2005 - now~450 profiles to 1000m

[5 profiles/day]

Vertical res. ~ 3 mHoriz res. ~ 3-5 km

n, n-1, n-2, n-3, n-4, n-5, n-6

Salinity Pot. temperature Chl Pot. Density


Large scale: water mass characteristics and distribution, mixed layer evolutionMesoscale (~50 km): fronts, eddiesSmall scale (~3-5km): oscillations, filaments – “subgrid phenomena“

Physical constraints on numerical models

Potential temperature along the glider trajectory

~ 2300 km - 3 months

Mixed layer depth




+PAP

80 km


U ~ 30cm/s




+


PAP




Salinity along the glider trajectory

Large scale: biological acitivity (mainly mixed layer), vertical distribution/integralMesoscale (~50 km): local modulations Small scale (~3-5km): diurnal cycle, filaments


Fluorescence (Chl) along the glider trajectory

Vertical integral = bio-activity in the mixed layer

validation elements for coupled physical-biogeochemical models

Glider Control from Land

Monitoring the health of the glider (Voltage, pump time, waypoints, comms...)

Remote steeringwith information from:

1) model analyses/forecasts 2) satellite imagery

“Glider Routing“ in development:use of a glider simulator in NRT to forecast glider trajectories

<< better steering >>

MERCATOR - SSH

AVHRR - SST

Coriolis ftp server

Data Access

http://www.ifm.uni-kiel.de/fb/fb1/po2/research/mersea/gliders/spray004_position.html

http://www.coriolis.eu.org/cdc/dataSelection/cdcDataSelections.asp

Mersea In-Situ Portaldata visualization

Coriolis data selection websitedata visualization and download

Quality Control and Metadata

QC procedures at Coriolis like for profiling floats. Profiles are considered as vertical.

- T and S outsiders based on historical data- Density inversions

are rejected

+ visual inspection

Metadata:Vehicle name, project, PIWaypoint (heading)Angle of ascent/descentTarget depthClimb depthTarget altitudeTime between surfacingCurrent correction

Dive #260 – “dirt“ in the conductivity cell

Assimilation of glider data

Temperature differences between MERCATOR North Atlantic 1/15°

and the in-situ observations

Before data assimilation

After data assimilation

glider

The model trajectory is modified by the data assimilation process,

to better fit the observations.

development required to better assimilate in-situ data

at the moment: correlation criteria for profiling floats

1 profile per 1°x1° per week>> in progress

Achievements and Plans

Demonstrated1) Steering possibility2) Long endurance3) Near real time physical and biogeochemical data 4) High density and resolution of the measurements5) Continuous measurements 6) Impact on operational numerical products

Next operations- Deployments in the Western Mediterranean

end of March

- Deployments in the North Atlantic1) Maintain surveys around PAP

recovery/redeployment

2) Similar survey around CIS June-Sept 2006

development of the glider system in-situ observations mersea 3rd annual meeting london, 06.03.2006...

Documents