Collecting and Assimilating Glider        Transects in the Levantine Sea                    May-August ‘09 data show Cypru...
Goal: Accurate description of mean state         ----> Improve Forecast Accuracy•   Method       •  Collect high resolutio...
Glider description• Battery-powered, buoyancy-  driven• 25-50 cm/s, 16-45o slope• CTD, oxygen, fluorescence,  optical back...
Seaglider description• Low-drag fairing over hull of compressibility ~= seawater• Lithium batteries, ~6 mo life (4600 km o...
Missions Accomplished• Since March 2009, over 1930  dives (3860 profiles)• Most to 1000 m
EYE of the Levantine                       TS properties• Depth-ave  velocity, Max  30 cm/s• Anti-cyclonic• Radius  ~40km•...
EYE of the Levantine (12/2009)• Sampling the warm core Cyprus Eddy• Labs: LOCEAN, LOV (fr), OGS (it), ULB (be), UCY-OC (cy...
EYE of the Levantine (12/2009)• Sampling the warm core Cyprus Eddy• Labs: LOCEAN, LOV (fr), OGS (it), ULB (be), UCY-OC (cy...
EYE of the Levantine                       Glider (Atalanta)•   23 Nov-1 Dec 2009•   Salinity (top)•   Temperature (mid)• ...
EYE of the Levantine           Glider Comparisons with MS Merian• 10 stations 4-5 Jan 2010• Dives 170-250 7-31 Jan 2010   ...
OceanVar                       Dobricic and Pinardi, 2008•   Calculates T and S residuals (model ―background‖ minus observ...
Results•   Numerical flow ―hindcast‖ simulation: Nov. 2009-April 2010•   Daily update of surface forcing and open boundary...
Results•   Numerical flow ―hindcast‖ simulation: Nov. 2009-April 2010•   Correction to T at 280 m•   Glider positions•   D...
Results•    EYE experiment assimilating only one glider‘s T, S profiles•    Sea surface elevation map at end of simulation...
Discussion•   Quantify the value of 1 glider, vs 6 gliders, vs floats+ships+gliders•   EYE experiment (so far only 0 and 1...
Discussion•   Quantify the value of 1 glider, vs 6 gliders, vs floats+ships+gliders•   EYE experiment (so far only 0 and 1...
Work in ProgressOperational Data Assimilation—TODAY: Glider mission and simulations: 16 December 2011 to present      Assi...
Work in Progress  Operational Data Assimilation—TODAY:Salinity at 360 m for control run (L) and D/A run (R) for this Wedne...
Future Work• New FP7 project, GROOM, has  started.• Goal: to design a European Glider  Infrastructure.• Heavily based on e...
Conclusions• Gliders improve forecasting skill• Quantifying the improvement is not  done yet• Eastern Levantine highly var...
Συλλογή και αφομοίωση δεδομενων Glider κατά μήκος διατομής της θάλασσας της Λεβαντίνης. Hayes D.
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Συλλογή και αφομοίωση δεδομενων Glider κατά μήκος διατομής της θάλασσας της Λεβαντίνης. Hayes D.

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10ο Πανελλήνιο Συμπόσιο Ωκεανογραφίας & Αλιείας
7-11 Μαΐου 2012, Αθήνα
Μεσόγειος Θάλασσα - Μαύρη Θάλασσα: Ένα ωκεανογραφικό «εργαστήριο»

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Συλλογή και αφομοίωση δεδομενων Glider κατά μήκος διατομής της θάλασσας της Λεβαντίνης. Hayes D.

  1. 1. Collecting and Assimilating Glider Transects in the Levantine Sea May-August ‘09 data show Cyprus Eddy D. Hayes1, P. Testor2 , S. Dobricic3, G. Zodiatis11OceanographyCenter, University of Cyprus, Nicosia, Cyprus2LOCEAN-IPSL/CNRS, Universite Pierre et Marie Curie, Paris, France3INGV/CMCC, Bologna, Italy
  2. 2. Goal: Accurate description of mean state ----> Improve Forecast Accuracy• Method • Collect high resolution temperature and salinity profiles over long periods in upper 1000 m (gliders) • Implement glider data assimilation (3DVAR) in operational regional model (CYCOFOS)• Results: • Cyprus eddy + Atlantic Water always found (>3/2009 with gliders) • Assimilation run shows difference from the control run• Analysis: • Cyprus Eddy dominates a complex circulation • Work needed to quantify improvement in forecast• Conclusions: • RT glider observations gliders unique: improve ocean forecasts
  3. 3. Glider description• Battery-powered, buoyancy- driven• 25-50 cm/s, 16-45o slope• CTD, oxygen, fluorescence, optical backscatter, currents• surface transmit/receive for data and instructions every 5h.• 1000 m dive capability Photo: A. Hannides
  4. 4. Seaglider description• Low-drag fairing over hull of compressibility ~= seawater• Lithium batteries, ~6 mo life (4600 km or 650 dives to 1km)• Iridium satellite phone for data, instruction transfer• Controlled with file exchange (commands, waypoints, configuration) Photo: U of Washington
  5. 5. Missions Accomplished• Since March 2009, over 1930 dives (3860 profiles)• Most to 1000 m
  6. 6. EYE of the Levantine TS properties• Depth-ave velocity, Max 30 cm/s• Anti-cyclonic• Radius ~40km• November 2009 to January 2010• Near Eratosthenes Seamount
  7. 7. EYE of the Levantine (12/2009)• Sampling the warm core Cyprus Eddy• Labs: LOCEAN, LOV (fr), OGS (it), ULB (be), UCY-OC (cy)• Gliders: physical and biogeochemical context for shipborne measurements – 6 gliders deployed from Limassol – 2 profiling floats – 4 surface drifters – shipborne measurements by CYBO (Cyprus), TARA (French), Merian (German)
  8. 8. EYE of the Levantine (12/2009)• Sampling the warm core Cyprus Eddy• Labs: LOCEAN, LOV (fr), OGS (it), ULB (be), UCY-OC (cy)• Gliders: physical and biogeochemical context for shipborne measurements – 6 gliders deployed from Limassol – 2 profiling floats – 4 surface drifters – shipborne measurements by CYBO (Cyprus), TARA (French), Merian (German)
  9. 9. EYE of the Levantine Glider (Atalanta)• 23 Nov-1 Dec 2009• Salinity (top)• Temperature (mid)• Dissolved Oxygen (bot)• Asymmetric: south branch of core more focused
  10. 10. EYE of the Levantine Glider Comparisons with MS Merian• 10 stations 4-5 Jan 2010• Dives 170-250 7-31 Jan 2010 • 14-22 Jan 2010• Depth-average currents from glider • Geostrophic Velocity (top) and (1000m) and from ADCP (800m) ADCP (bottom) 0
  11. 11. OceanVar Dobricic and Pinardi, 2008• Calculates T and S residuals (model ―background‖ minus observations) at every time step data are present• After POM, calculates ―correction‖ T and S based on residuals in window (1.5d)• Applies corrections at the beginning of the next run (20 time steps). Glider (red) and model (blue) S,T profiles Difference (black) and correction (green) 8 Dec 2009
  12. 12. Results• Numerical flow ―hindcast‖ simulation: Nov. 2009-April 2010• Daily update of surface forcing and open boundary conditions• Quantify the value of 1 glider, vs 6 gliders, vs floats+ships+gliders• EYE experiment (so far only 0 and 1 completed) Corrections on S and T at 300 m 8 Dec 2009
  13. 13. Results• Numerical flow ―hindcast‖ simulation: Nov. 2009-April 2010• Correction to T at 280 m• Glider positions• DAILY
  14. 14. Results• EYE experiment assimilating only one glider‘s T, S profiles• Sea surface elevation map at end of simulation: 19 April 2012 No assimilating Assimilating glider data The difference
  15. 15. Discussion• Quantify the value of 1 glider, vs 6 gliders, vs floats+ships+gliders• EYE experiment (so far only 0 and 1 completed—see difference below)• See problem at BC
  16. 16. Discussion• Quantify the value of 1 glider, vs 6 gliders, vs floats+ships+gliders• EYE experiment (so far only 0 and 1 completed—see difference below)• See problem at BC
  17. 17. Work in ProgressOperational Data Assimilation—TODAY: Glider mission and simulations: 16 December 2011 to present Assimilated in CYCOFOS, compared to control run
  18. 18. Work in Progress Operational Data Assimilation—TODAY:Salinity at 360 m for control run (L) and D/A run (R) for this Wednesday Need to quantify the improvement by comparing to independent data E.G.: SST, XBT, SLA+MDT, cruise CTD/ADCP
  19. 19. Future Work• New FP7 project, GROOM, has started.• Goal: to design a European Glider Infrastructure.• Heavily based on existing, but integrated and improved.‘ • Recommend payloads, protocols, operation centers, etc. • Support policy AND research • monitoring for parameter ‗X‘ • availability for process study ‗Y Photo: TARA Oceans
  20. 20. Conclusions• Gliders improve forecasting skill• Quantifying the improvement is not done yet• Eastern Levantine highly variable and full of mesoscale: need real time data Acknowledgements• Funding: FP7-ECOOP, FP7-GROOM, Cyprus RPF and UCY, TARA/Oceans.• Colleagues: MFS, U of Athens (ALERMO and Skiron providers)• Launch/recovery support: Department of Fisheries and Marine Research Photo: A. Hannides

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