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SUMMARY:A synthesis of Antarctic ice-ocean boundary observations from the 
 underwater vehicle Icefin - Peter Washam (Georgia Institute of Technology)
DTSTART:20210224T140000Z
DTEND:20210224T150000Z
UID:TALK156274@talks.cam.ac.uk
CONTACT:Dr Irena Vankova
DESCRIPTION:The accumulated mass loss from the Earth’s cryosphere curren
 tly represents the largest contribution to global sea level rise.  A large
  portion of this mass loss is driven by physical processes occurring at th
 e marine margin of the Antarctic and Greenland ice sheets\, where the ice 
 sheet interacts with the ocean. However\, there are extremely limited dire
 ct observations of the ice-ocean interface where these two physical enviro
 nments meet. Here we synthesize three years of ice and ocean observations 
 in Antarctica from McMurdo Sound and beneath the Ross and Thwaites ice she
 lves\, using hydrographic and sonar data\, and video footage from the unde
 rwater vehicle Icefin. Near-ice ocean conditions vary between these enviro
 nments from below freezing to greater than two degrees above freezing\, wi
 th considerable variability in current velocities. Ice base morphology lik
 ewise varies within and between environments\, with ablating ice forming s
 callops\, runnels\, and terraces with horizontal scales of meters and vert
 ical scales of centimeters to meters. Supercooled waters in turn form mari
 ne ice platelets\, which accumulate in both unconsolidated and rigid bulbo
 us masses observed at meter scales. These variations in ice basal roughnes
 s affect the turbulent transfer of heat and salt from the ocean to the ice
 \, and represent one of the most poorly constrained parameters in the equa
 tions that describe ice-ocean interactions. Our results provide direct obs
 ervations of the ice-ocean boundary in several environments\, and therefor
 e inform on these processes that are critical for the future behavior of t
 he Antarctic and Greenland ice sheets\, as well as other peripheral ice ca
 ps that contain marine-terminating outlet glaciers.
LOCATION:British Antarctic Survey\, Zoom
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