報告人：Ted A. Scambos(資深研究員Senior Research Scientist)
時間：2023.2.23 10:00-11:30
Zoom會議：892-068-55308
密碼：見郵件或班級通知
報告人簡介
Dr. Ted Scambos is now a Senior Research Scientist at the University of Colorado’s Earth Science and Observation Center at University of Colorado Boulder. Prior to this position, he was Lead Scientist at the National Snow and Ice Data Center for 14 years (2004-2018), a part of the university. He received degrees in geology and geochemistry from University of Stony Brook, Virginia Tech, and the University of Colorado. Dr. Scambos' research has focused on the use of remote sensing to study the polar regions, and the exploration of the effects of climate change on the poles. He has been on 21 expeditions to Antarctica, working with the British, Australian, South Korean, Argentinian, and Norwegian research programs to explore most areas of the continent and its surrounding ocean. He has published extensively on polar ice loss and glacier acceleration, changes in Arctic and Antarctic sea ice, the evolution of icebergs, and wind-snow interactions on the high East Antarctic Plateau. He is currently the Principal Investigator for the Science Coordination Office of the International Thwaites Glacier Collaboration. Dr. Scambos contributes to two ongoing science analysis blogs, the Arctic Sea Ice News and Analysis report (nsidc.org/arcticseaicenews/) and Greenland Today report on ice sheet melting (nsidc.org/greenland-today).
報告簡介
The Plateau of East Antarctica, above 1500 m elevation, spans an area of 8.5 million km^2, roughly the size of Australia. In this region, surface melting never occurs, snow accumulation is very low (averaging 6 to 10 cm water equivalent), and temperatures reach -90C in some areas in winter. In this extreme environment, unlike any other on Earth, the interactions between wind and snow, evaporation and recrystallization, and exchange of energy between the snow and the sky completely shape the characteristics of the surface. Weather conditions are dominated by katabatibc winds, which in turn are driven by gravity acting on the cold near-surface air layer (the ‘inversion layer’). Over wide areas of the surface, these winds create large (1-4 km wavelength) shallow (1-5 meters amplitude) dunes, called ‘snow megadunes’, that are formed by windward accumulation of snow and leeward ablation that leaves no new snow accumulation, in some cases for centuries. This prolonged period of exposed old snow, experiencing many summer-winter cycles, leads to coarse recrystallized firn below the surface and a polished ‘wind glaze’ crust.
