Distribution of δ 18O in surface snow along a transect from Zhongshan Station to Dome A, East Antarctica

Abstract

Surface snow samples were collected during the 14th (1997/1998) and 24th (2007/2008) Chinese National Antarctica Research Expeditions along a transect from Zhongshan Station to Dome A. The stable oxygen isotope ratios of these samples were measured to investigate their relationships with temperature and geographical parameters (latitude, longitude, altitude and distance to the coast). The results reveal a strong positive correlation (R=0.945) between δ18O and mean annual temperature, with a gradient of 0.84‰°C−1, which is a little higher than that in Terre Adelie Land. Regression analyses also show that the δ18O of surface snow is strongly correlated with distance to the coast (R=0.942), latitude (R=0.942), and altitude (R=0.941). But no significant correlation was found between δ18O and longitude in study area. Altitude should be the most important factor influencing the δ18O distribution because of distinctive topography. The δ18O-altitude and T-altitude gradients along this transect are determined to be −1.1‰/100 m and 1.31°C/100 m, respectively.