Takeshi Tamura, ACE CRC and NIPR Japan
12:00-12:50pm Monday Nov 7
Seminar room, IMAS Sandy Bay

Abstract:
Variability in polynya-driven dense shelf water formation can potentially impact the production of Antarctic Bottom Water (AABW) and its input to the global climate system. The long-term climate variability and change of dense shelf water formation is intermittently impacted by abrupt changes to the dynamic ice front. We examine the change in sea ice production for the Adelie and George V Land polynya region (East Antarctica, 140-150E), which is the local source of dense shelf water export and AABW production to the Australian-Antarctic Basin, following the translocation of iceberg B9B and subsequent calving of the Mertz Glacier Tongue (MGT) in February 2010.  During the following winter seasons in 2010 and 2011 there has been decreased polynya activity and sea ice production, resulting from changes to the ‘icescape’ that have impacted upon polynya morphology and subsequent sea ice production. Using satellite-derived sea ice data and heat flux calculations, we find that tot

Biography:
Takeshi has been working under the theme of “Detection of Antarctic coastal polynyas from passive microwave data and estimation of sea ice production there”. This study estimates sea ice thickness in the thin ice region (coastal polynyas) in the Southern Ocean from satellite data (i.e., SSM/I, AVHRR, MODIS), and maps ice production in Antarctic coastal polynyas using the heat flux calculation and a sea ice thickness algorithm (collaboration with Drs. Don Cavalieri and Thorsten Markus of NASA GSFC). For the validation of satellite data with in-situ observation data, he took part in the Australian-led international experiment ARISE in September-October 2003. He joined the similar Australian-led international experiment SIPEX again in September-October 2007, to validate satellite microwave data with sea ice thickness data acquired in-situ and from a heli-borne portable passive microwave radiometer.