A 2000-year annual record of snow accumulation rates for Law Dome, East Antarctica

• Published in: Climate of the Past
• Main Authors: Roberts, J, Plummer, C, Vance, T, van Ommen, T, Moy, A, Poynter, S, Treverrow, A, Curran, M, George, S
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2015
• Subjects: Earth Sciences; Physical Geography and Environmental Geoscience; Glaciology; Antarctic; East Antarctica; Law Dome; Law Dome Summit; Pacific; Antarc*; Antarctica; Ice Sheet
• Online Access: https://doi.org/10.5194/cp-11-697-2015; http://ecite.utas.edu.au/100223

Accurate high-resolution records of snow accumulation rates in Antarctica are crucial for estimating ice sheet mass balance and subsequent sea level change. Snowfall rates at Law Dome, East Antarctica, have been linked with regional atmospheric circulation to the mid-latitudes as well as regional Antarctic snowfall. Here, we extend the length of the Law Dome accumulation record from 750 years to 2035 years, using recent annual layer dating that extends to 22 BCE. Accumulation rates were calculated as the ratio of measured to modelled layer thicknesses, multiplied by the long-term mean accumulation rate. The modelled layer thicknesses were based on a power-law vertical strain rate profile fitted to observed annual layer thickness. The periods 380442, 727783 and 19702009 CE have above-average snow accumulation rates, while 663704, 933975 and 14291468 CE were below average, and decadal-scale snow accumulation anomalies were found to be relatively common (74 events in the 2035-year record). The calculated snow accumulation rates show good correlation with atmospheric reanalysis estimates, and significant spatial correlation over a wide expanse of East Antarctica, demonstrating that the Law Dome record captures larger-scale variability across a large region of East Antarctica well beyond the immediate vicinity of the Law Dome summit. Spectral analysis reveals periodicities in the snow accumulation record which may be related to El NioSouthern Oscillation (ENSO) and Interdecadal Pacific Oscillation (IPO) frequencies.