OCES Departmental Seminar: Record lows and far-reaching impacts: Antarctic sea ice in a changing world

2:30pm - 3:30pm
Room 5562 (Lift 27-28, Academic Building)

Antarctic sea ice has experienced five extreme events in the last decade: three record lows, and two record highs. These extreme sea ice events have wide ranging impacts on the ocean, other cryospheric components, and the Southern Ocean ecosystem as well as far field repercussions. Extreme low summer sea ice results in an increased loss of multiyear fastice, increases in coastal exposure and changes the seasonality of the sea-ice cycle. Surface ocean warming during the summer is observed due to the ice-albedo feedback, resulting in changes to the rate of watermass transformation. We find that ice-shelf calving is correlated with sea-ice area, so that years with less sea ice show increased calving. Within the annual cycle, prolonged open water affects the seasonality of surface phytoplankton blooms. In addition, changes to the sea-ice seasonal cycle alter the input of iron from melting sea ice, subsequently modifying primary productivity. Under-ice algae are strongly affected by changes to the sea-ice coverage, and years with less ice show substantially reduced under-ice primary productivity. The impacts on higher trophic levels are complex, but include habitat loss and impacts on prey availability. The loss of coastal fast ice in the summertime causes logistical challenges for Antarctic fieldwork and resupply missions for Antarctic research stations. Changes in the sea-ice and fast-ice seasonality as well as in the physical properties of the ice have profound effects on coastal and ice-infested water operations, requiring increased observations and analysis of the ice conditions. Changing accessibility of the Southern Ocean may lead to renewed tensions around Antarctic treaty negotiations. Understanding the full impacts of recent, and future, sea ice extremes requires a broad observational network that spans the physical and ecological systems of Antarctica and the Southern Ocean.  

講者/ 表演者:
Dr. Edward Doddridge
Institute for Marine and Antarctic Studies (IMAS), Tasmania

Dr. Edward Doddridge is a Physical Oceanographer working in the Australian Antarctic Program Partnership (AAPP) based at the Institute for Marine and Antarctic Studies (IMAS) in Hobart, Tasmania. His work uses numerical models, observations, and theory to further our understanding of complex physical phenomena in the Southern Ocean. Dr. Doddridge completed his PhD under the supervision of David Marshall at the University of Oxford in the UK, after which he spent three years in Boston working at MIT with John Marshall. He is a prize-winning jam maker and Research Associate in Physical Oceanography at the Institute for Marine and Antarctic Studies in Tasmania.

語言
英文
適合對象
教職員
研究生
本科生
主辦單位
Department of Ocean Science
聯絡方法

If you are interested in talking with Dr. Doddridge, please contact Prof. Julian Mak (jclmak@ust.hk).

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