Annual report 2005-06.indd - Antarctic Climate and Ecosystems ...

sea-level riseProgress against contractual milestonesOutcomes:• Estimates of sea level change resulting from anthropogenic climate change used as one of the basesfor intergovernmental climate change negotiations.• Estimates of sea level change as an essential input to coastal zone management and other planningconsiderations in Australia and in neighbouring nations in the South PacificOutput / Milestone Date ProgressRevised estimates of historical (20 th centuryand early 21 st century) sea-level change2004-09 2005: Published revised estimates for 1950-2000.2005: Showed that coastal sea level is risingat about the same rate as global averaged sealevel over the period 1950 to 2000.2006: Narrowed the uncertainty of estimatesof the 20 th century rate of sea level rise andshowed that the rate of sea level rise hasincreased during the 20 th century.Revised estimates of ocean thermalexpansion from observations and models(both the CSIRO and AWI models)Revised estimate of the 20 th centuryAntarctic ice sheet contribution to sealevelchange derived from a comparison ofmeasured ice discharge (field observationsand remote sensing) with results from abalance flux model forced with improvedestimates of accumulation distribution andtemporal variability (from field observations,meteorological models and ice cores)2006: Provided the first comprehensiveestimate of the rate of sea-level rise during thelatter half of the 20 th century for Pacific andIndian Ocean islands and for Australia since1920.2005-09 2005: Produced estimates of 20 th centuryocean thermal expansion from the CSIROMark 3 model that will appear in the IPCC 4 thAssessment Report.2005: Showed (Nature 2005) that volcaniceruptions have a significant impact on oceanheat content and steric sea level. Post1960 volcanic eruptions masked part of theacceleration that would otherwise have beenpresent.2005-09 2005-2006: Comparison of historical field datawith satellite data has detected significant icemass loss on the Totten Glacier and a smallmass gain over the Law Dome.Historical ANARE field data have been compiledfor a reassessment of the East Antarctic massbudget, and some earlier regional balanceestimates have been revised. These havebeen compared with a test run of the balanceflux model using a reference accumulationcompilation. Alternative descriptions of iceaccumulation are being sought to explore theuncertainties in the input to the mass budget.Antarctic Climate & Ecosystems CRC - Annual Report 2005-06 47