Temporal variations of surface mass balance over the last 5000 years around Dome Fuji, Dronning Maud Land, East Antarctica

We reconstructed surface mass balance (SMB) around Dome Fuji, Antarctica, over the last 5000 years using the data from 25 15 shallow ice cores and 7 snow pits. The depth-age relationships for the ice were determined by synchronizing them with a layer-counted ice core from West Antarctica (WAIS Divide ice core) using volcanic signals. The reconstructed SMB records for the last 4000 years show spatial patterns that may be affected by their locations relative to the ice divides around Dome Fuji, proximity to the ocean, and wind direction. The SMB records from the individual ice cores and snow pits were stacked to reconstruct the SMB history in the Dome Fuji area. The stacked record exhibits a long-term decreasing trend at - 30 0.037±0.005 kg m -2 per century over the last 5000 years in the preindustrial period. The decreasing trend may be the result of long-term surface cooling over East Antarctica and the Southern Ocean, and sea-ice expansion in the water vapor source areas. The multidecadal to centennial variations of the Dome Fuji SMB after detrending the record shows four distinct periods during the last millennium: mostly negative period before 1300 C.E., slightly positive for 1300–1450 C.E., slightly negative for 1450–1850 C.E. with a weak maximum around 1600 C.E., and strong increase after 1850 C.E. These variations are consistent with those of previously reconstructed SMB records in the East Antarctic plateau. The low accumulation rate with additional sites further away (200–400 km), both on the windward and leeward sides of the main ice divides with respect to the origin and transport paths of moisture. At the Dome Fuji station, two deep ice cores have also been drilled in the 1990s and 2000s to the depths of 2503 m (340 kyr) (DF1) and 3035 m (720 kyr) (DF2), 125 respectively (Watanabe et al., 1997a, 1997b; Dome Fuji Ice Core Project Members, 2017; Motoyama et al., 2021). Two shallow cores (DF1993 and DF2001) are the shallow parts of the DF1 and DF2 deep ice cores. Because the NDF2018 core is the longest and oldest shallow ice core in this study (151 m long, covering ~4800 years), we use the records of DF1 and DF2 deep cores to cover the same period. Four ice cores (DF1, DF2, NDF2018, and NDFN cores) cover more than 4000 years, three ice cores (DF1997, DFS2010 and DFS2011 cores) cover 1500 years, and six ice cores (MD364, NDF2013, S79, S80, 130 DFNW and DFSE cores) cover 800 years or less. The DF1997 core has poor ice core recovery and uncertain depth assignments for 0–20 m, thus we use the data only below 20 m. The DF1999 core was measured for permittivity (for density estimation), but not for DEP for volcanic matching, thus only used for estimating the average density profile at Dome Fuji. core). Our new SMB reconstructions took advantage of detailed and precise depth-age controls for the ice cores owing to high-resolution volcanic synchronization with the WAIS Divide ice core. We also considered vertical ice thinning for all cores, and used high-resolution permittivity data 690 for estimating high-precision density profiles for most of the cores. Because the accumulation rate is low and its variability is relatively large in the high-elevation plateau in East Antarctica (e.g., above 3,000 m a.s.l.), we stacked all available SMB records from the individual ice cores and snow pits for a reliable reconstruction of the SMB history in the Dome Fuji area.