SIPEX II AUV MERTZ GLACIER CALVING SEAL OCEANOGRAPHY Update from Guy Williams AUV/Sea Ice Specialist Sea Ice Program Cryosphere
Jan 19, 2016
SIPEX II AUVMERTZ GLACIER CALVING
SEAL OCEANOGRAPHY
Update from Guy WilliamsAUV/Sea Ice Specialist
Sea Ice ProgramCryosphere
SIPEX II AUV
• Major setback after loss of collaboration with Memorial University and long-range AUV capability for Cryosat-II Calibration/Validation
• Major comeback with new collaboration with WHOI ‘SeaBed’ vehicle for floe-scale measurements of ice draft during SIPEX-II
• Collaborative links with UK ICEBELL mission in the Weddell/Bellingshausen Sea in Nov. 2010
• Better integration with other Ice Station projects
• Floe scale survey (500 x 500 m)• 230 kHz multibeam sonar• CTD + ADCP• Hyper spectral radiometer• 4 man team• ~$250—300K• Integrated with surface
measurements and ROV program
Important collaborative links with UK ICEBELL mission in the Weddell/Bellingshausen Sea in Nov. 2010
Ice thickness maps from 4 unique ice stations
Wilkinson et al., Williams (in prep)
2011 - Timeline
• April - Visit to Scottish Association of Marine Science (SAMS), UK, to establish collaboration with the ICEBELL project.
• May - Visit to Hobart by Hanumant Singh (WHOI) to establish AUV contract for SIPEX-II. Meetings with AAD operations and Aurora Australis crew
• July - Visit to WHOI, USA, to work with AUV team and ICEBELL project leader on AUV operations for SIPEX and the processing of AUV data from the ICEBELL project.
• September - Visit to Hawaii, USA for pre-cruise mobilisation experience with the SEABED vehicle.
• Ongoing processing and analysis of ICEBELL data with SAMS and WHOI for co-authorship on upcoming publications from the UK groups.
Impacts of the Mertz Glacier Calving
Ocean-Ice Modelling
Kusahara, Hasumi and Williams, Nature Comm. 2011
Sea ice via Satellite Analyses
Tamura, Williams, Fraser and Ohshima (in review Nature Geoscience)
• 23% reduction in modelled dense shelf water export• 27-36% decrease in sea ice production• Greater than 0.05 decrease in salinity, equiv. to last 50 years of long-term freshening • Contribution to observed changes in oceanography in Rintoul et al., (in prep)
Seals as Polar Ocean Observers in the Prydz Bay/Amery Ice Shelf and Cape Darnley regions
• Over 15,000 new CTD profiles from elephants seals deployed from Davis Station and Kerguelen Island
• Amazing new observations of high salinity shelf water and dense shelf water overflows relevant to Cape Darnley/Prydz Bay Antarctic Bottom Water.
• Sea ice growth rate estimates for the McKenzie Bay and Barrier polynyas
• Unique summer-fall-winter observations on the continental shelf, across the Amery Ice Shelf and across the southern ocean.
1st author manuscripts near submission for GRL-style journal and the PLoS-ONE Special volume on ‘Trends and Change’ resulting from the Australia-
Japan Antarctic Biology workshop in Feb. 2011
with Hindell, Field, Roquet, Tamura and Herraiz-Borreguero