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SEA ICE AND POLAR OCEANOGRAPHY GROUP

SEA ICE AND POLAR OCEANOGRAPHY GROUP. Review 2004-05. SAMS Dunstaffnage Marine Laboratory Jeremy Wilkinson Nick Hughes Martin Doble. DAMTP Centre for Mathematical Sciences University of Cambridge Peter Wadhams Joao Rodrigues Arthur Kaletzky Olivia Low. Staff. 2004-05.

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SEA ICE AND POLAR OCEANOGRAPHY GROUP

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  1. SEA ICE AND POLAR OCEANOGRAPHY GROUP Review 2004-05 SAMS and DAMTP 2004-05

  2. SAMSDunstaffnage Marine Laboratory Jeremy Wilkinson Nick Hughes Martin Doble DAMTPCentre for Mathematical SciencesUniversity of Cambridge Peter Wadhams Joao Rodrigues Arthur Kaletzky Olivia Low Staff SAMS and DAMTP 2004-05

  3. 2004-05 • Arctic submarine fieldwork • Autosub Under Ice • JR106a East Greenland • JR97 Weddell Sea • GreenICE • IRIS • Baltic Sea ice fieldwork SAMS and DAMTP 2004-05

  4. Arctic Submarine Fieldwork • Royal Navy ICEX-04 • Submarine HMS Tireless • April 2004 • Sea ice thickness and oceanography • Investigated: • Greenland Sea • CONVECTION chimney • Fram Strait • Molloy Deep Eddy • Marginal Ice Zone • Arctic Ocean • Morris Jessup Rise • Lincoln Sea and Ice Station SAMS (GreenICE) • North Pole SAMS and DAMTP 2004-05

  5. Measuring Ice Thickness • Upward echosounders • Forward • Fin • Stern • Sidescan • Forward Look SAMS and DAMTP 2004-05

  6. Preliminary Ice Thickness 85°N SAMS and DAMTP 2004-05

  7. Atlantic Water Depth 85°N SAMS and DAMTP 2004-05

  8. Remote Sensing Validation • Envisat ASAR • Scenes coincident with submarine track • Passive microwave cluster analysis • Alternative method for obtaining polar synoptic sea ice thickness SAMS and DAMTP 2004-05

  9. Use of MODIS to validate ASAR interpretation • Cloudy over area of interest at 82°N on 1 April 2004 • However possibility of cloud-free comparison on other days or areas • Similar ASAR dataset from ice edge at 78°N SAMS and DAMTP 2004-05

  10. GreenICE GreenICE seeks to measure and understand the changes that have occurred in sea ice north of Greenland, in response to a reversal in the Arctic Oscillation (AO). This response will be related to past changes, as determined from sediment cores, placing them in the context of natural climate variability. Benefits will include a better understanding of Europe’s medium-term climate prospects and a better understanding of ice conditions in the Arctic Ocean, past, present and future. • Co-ordinated by SAMS • Pilot experiments from RV Polarstern and Beaufort Sea ice camp (APLIS) 2003 • Main ice camp experiment May 2004 • Combined buoy monitoring with sediment coring (GEUS) and remote sensing SAMS and DAMTP 2004-05

  11. Wave Measuring Buoys GPS antennae 4m apart to give reliable heading close to magnetic Pole Solar panel Iridium antenna SAMS and DAMTP 2004-05

  12. Ice Station SAMS • Ice camp • May 2004 • 85°N 62°W • Full scientific programme • Sediment cores • Ice thickness measurement Location of GreenIce buoys SAMS and DAMTP 2004-05

  13. Buoy Drift Data Tracks of GreenICE buoys from launch (date shown) to 10 Nov 04. Dots indicate buoy positions on the first of each month Buoy 3 was started when the camp was abandoned SAMS and DAMTP 2004-05

  14. IRISIce Ridge Information System • The overall strategy is to develop ice modelling and SAR interpretation so that ridging parameters are obtained, to include the parameters into systems of ice information delivery, to relate the parameters to the trafficability of ships, and finally develop methods to apply the enhanced ice information in routeing and decision making during marine operations. • Field work on ridge structures in Baltic 2004 and 2005 SAMS and DAMTP 2004-05

  15. Big Ridge SAMS and DAMTP 2004-05

  16. Big Ridge – Ice Thickness SAMS and DAMTP 2004-05

  17. SAMS and DAMTP 2004-05

  18. Big Ridge - Freeboard SAMS and DAMTP 2004-05

  19. Small Ridge SAMS and DAMTP 2004-05

  20. Small Ridge – Ice Thickness SAMS and DAMTP 2004-05

  21. Rubble Field SAMS and DAMTP 2004-05

  22. Autosub Under Ice • August 2004 RRS James Clark Ross sailed to the Belgica Bank • Sensors: Multibean Sonar, ADCP and Seabird 911 SAMS and DAMTP 2004-05

  23. North East Water Polynya MODIS visual image from 12 August. The bathymetry of the study area and Autosub II runs are shown. Bathymetry of the study area. CTD locations are shown for JCR106a (blue ‘*’, 1-19), and historical data 1993 (red ‘*’, courtesy G. Budeus) and 1979 (green , ‘*’, courtesy T. Wen). SAMS and DAMTP 2004-05

  24. Currents Beneath The NØIB Vertical section of northwards current velocity (bottom) and ice draft (top) from Mission 365 (east to west) beneath the NØIB. Previous and new estimate of bathymetry shown. A-D indicate multibeam plots in next slide. SAMS and DAMTP 2004-05

  25. Under Ice Images From EM-2000 b) a) c) d) Ice draft from Autosub-II multibeam sensor. Examples of a) Along-track ridge system, c) Lead through fast ice and b)Transition from across-track ridge system to ‘level’ ice d) Fast ice (after a summer melt season). SAMS and DAMTP 2004-05

  26. Validating AUV Ice Thickness SAMS and DAMTP 2004-05

  27. Validating AUV Ice Thickness • Collaborative programme with AWI. Run Autosub under the ice and ground truth using different techniques. • Ground EM • Airborne EM • Wave measurements SAMS and DAMTP 2004-05

  28. PDF of ice draft during: Entire run in: 0 to 64 km Through the EGC: 0 to 30 km Through the NEGCC: 30 to 64 km Probability Density Function By combining the autosub measurements of currents (ADCP) with the ice draft (multi-beam) we can see that the northward flowing current, North East Greenland Coastal Current (NEGCC) has a different ice regime to the southward flowing East Greenland Current (EGC). SAMS and DAMTP 2004-05

  29. Autosub: Conclusions The combination of scientific instruments on board Autosub has allowed us to investigate both the sea ice and oceanographic properties of the North East Water Polynya (NEW). Major insights include: • First mapping of the topography under the ice barrier (NØIB). This barrier is instrumental in the formation of the NEW! • First continuous current and oceanographic measurements of the region. • First measurements of the bathymetry of the region. This has shown significant errors in the existing charts. Autosub’s unique abilities have led to the successful interaction between scientists and the Autosub team through the NERC funded Autosub Under Ice programme. This has produced important groundbreaking science. SAMS and DAMTP 2004-05

  30. Venue For Next Meeting? • Dunstaffnage Marine LaboratoryOban, Scotland • Friday 15 September 2006 • Coincides with the Challenger Society meeting at SAMS that week SAMS and DAMTP 2004-05

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