GROOM Trieste 2013
Cutting edge Science and Research from
a Glider Base in the North Atlantic
by
Toby Sherwin, Mark Inall, Estelle Dumont and Dima Aleynik
Scottish Association of Marine Science (SAMS)
GROOM Trieste 2013
SAMS
Local test sites
West coast of ScotlandEasy access to sheltered deep water and the North
Atlantic
Loch Linnhe (200m)
Ardmucknish Bay (30m)
Loch Etive (140m)
10 km
North Atlantic launch point
GROOM Trieste 2013
ONGOING WORK
The Ellett Line(Gliders providing better monitoring and novel
science)
GROOM Trieste 2013
The Rockall Trough and Ellett Line
ENAW – Eastern North Atlantic WaterWTOW – Wyville Thomson Ridge Overflow WaterLSW – Labrador Sea WaterAABW – Antarctic Bottom Water
?
?
GROOM Trieste 2013
60 years of θ and S in the Rockall Trough
from: Sherwin, Read, Holliday and Johnson (2012) ICES Journal of Marine Science; doi:10.1093/icesjms/fsr185
OWS surface readings
RRS full depth readings
(HADSST surface temps)
Glider readings
+ winter top 4 m● winter top 800 m
GROOM Trieste 2013
Glider observations
• Mission 1: winter 2009/2010 Rockall Trough• Mission 2: summer 2011 Scotland to
Iceland• Next Mission: autumn 2013
Mission 1
Mission 2
GROOM Trieste 2013
Glider surface and full depth θ and S winter 2009/10
Top 12 m saltier and slightly warmer than top 800 m
Top 12 m fresher and much warmer than top 800m
Stratified Mixed
GROOM Trieste 2013
Ellett Line (Rockall Trough) Summary
Particular monitoring results from a glider:
• First winter upper 1000 m θ and S since 2006
• Overturning took place from mid-November to mid-January
• Salinity gradient reversed at the start of the overturning
• (Mesoscale motions follow next ...)
Long term implications:
• Better long term analysis and understanding of annual (and
seasonal) variability
• Opportunities for international collaboration (see later ...)
GROOM Trieste 2013
EXCITING STUFF
from the Ellett Line
GROOM Trieste 2013
Observations of θ, S, σt and velocity binned into 0.25° longitude cells
Nov / Dec 2009
GROOM Trieste 2013
Glider drift (to 1000 m) and equivalent altimeter geostrophic currents
GROOM Trieste 2013
Rockall
Rockall
Shelf
Shelf
Paper being prepared in collaborationwith Dima Alyenik (SAMS)
AVISO surface height anomaly Nov / Dec 2009
Slope current reversal?
GROOM Trieste 2013
Interim Research Results
• Rockall Trough has slow moving meso-scale eddies
• Typical eddy currents in upper 1000 m up to 25 cm/s
• Reversals of the northward flow in the eastern Trough
• These currents are driven by eddies deep waters of the Trough
(LSW and AABW)
• *Glider data show that deep water eddies can be tracked using
synthesised altimeter data*
Further work:
• Are WTOW eddies (from north) also in the mix?
• How well do altimeter and glider drift currents compare?
• Complete paper
GROOM Trieste 2013
OTHER NAGB ACTIVITIES
Nature, 9 May, 2013
SAMS Glider section
OSNAP (US / Canada / Holland / Germany / UK): $44m
NABG
OSNAP
GROOM Trieste 2013
Other work in the NE Atlantic
UK FASTNEt shelf edge study:a) Malin Shelf edge exchangeb) Faroe-Shetland Channel (with
MSS, Aberdeen)c) NACLIM partner collaboration
with Ellett Line
a)
b)
c)
GROOM Trieste 2013
Planned development of The North Atlantic Glider Base at SAMS
in association with NERC’s Marine Autonomous and Robotic Systems facility
(MARS), headed by NOC (Southampton and Liverpool)
A dedicated test facility for visitors:
• A covered glider building with Iridium / GPS repeaters, ballasting tank, WiFi etc
+ access to sheltered deep water
In house operational and research activities:
• Operating 5 – 6 gliders
• 1.5 PIs, 2 postdocs + 1-2 PhDs
• 1.5 technicians and 6 trained pilots
• Fully structured web interface (SAMS’ web interface to be extended and
incorporated by MARS)
• Data feeds on to BODC, GTS etc
• Publication of research papers
Shortly Coming to SAMS
GROOM Trieste 2013
Conclusions
• The Ellett Line glider programme is starting to show real
scientific benefit
• A much better understanding of mesoscale activity in the
Rockall Trough is emerging
• SAMS is extending its glider activity into other collaborative
programmes
Top Related