8-ix-2005SAMS and DAMTP SEA ICE AND POLAR OCEANOGRAPHY GROUP Review

8-ix-2005SAMS and DAMTP Staff 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

8-ix-2005SAMS and DAMTP Arctic submarine fieldwork Autosub Under Ice –JR106a East Greenland –JR97 Weddell Sea GreenICE IRIS –Baltic Sea ice fieldwork

8-ix-2005SAMS and DAMTP 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

8-ix-2005SAMS and DAMTP Measuring Ice Thickness Upward echosounders –Forward –Fin –Stern Sidescan Forward Look

8-ix-2005SAMS and DAMTP Preliminary Ice Thickness 85°N

8-ix-2005SAMS and DAMTP Atlantic Water Depth 85°N

8-ix-2005SAMS and DAMTP Remote Sensing Validation Envisat ASAR –Scenes coincident with submarine track Passive microwave cluster analysis –Alternative method for obtaining polar synoptic sea ice thickness

8-ix-2005SAMS and DAMTP 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

8-ix-2005SAMS and DAMTP 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

8-ix-2005SAMS and DAMTP Wave Measuring Buoys Solar panel Iridium antenna GPS antennae 4m apart to give reliable heading close to magnetic Pole

8-ix-2005SAMS and DAMTP Ice Station SAMS Ice camp –May 2004 –85°N 62°W –Full scientific programme Sediment cores Ice thickness measurement Location of GreenIce buoys

8-ix-2005SAMS and DAMTP 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

8-ix-2005SAMS and DAMTP IRIS Ice 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

8-ix-2005SAMS and DAMTP Big Ridge

8-ix-2005SAMS and DAMTP Big Ridge – Ice Thickness

8-ix-2005SAMS and DAMTP

8-ix-2005SAMS and DAMTP Big Ridge - Freeboard

8-ix-2005SAMS and DAMTP Small Ridge

8-ix-2005SAMS and DAMTP Small Ridge – Ice Thickness

8-ix-2005SAMS and DAMTP Rubble Field

8-ix-2005SAMS and DAMTP Autosub Under Ice August 2004 RRS James Clark Ross sailed to the Belgica Bank Sensors: Multibean Sonar, ADCP and Seabird 911

8-ix-2005SAMS and DAMTP North East Water Polynya 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). MODIS visual image from 12 August. The bathymetry of the study area and Autosub II runs are shown.

8-ix-2005SAMS and DAMTP 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.

8-ix-2005SAMS and DAMTP Under Ice Images From EM-2000 Ice draft from Autosub-II multibeam sensor. Examples of a) Along-track ridge system, c) Lead through fast ice and a) b) c)d) b)Transition from across-track ridge system to ‘level’ ice d) Fast ice (after a summer melt season).

8-ix-2005SAMS and DAMTP Validating AUV Ice Thickness

8-ix-2005SAMS and DAMTP 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

8-ix-2005SAMS and DAMTP 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). 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

8-ix-2005SAMS and DAMTP 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.

8-ix-2005SAMS and DAMTP Venue For Next Meeting? Dunstaffnage Marine Laboratory Oban, Scotland Friday 15 September 2006 Coincides with the Challenger Society meeting at SAMS that week