Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4683153 | Polar Science | 2016 | 12 Pages |
We quantify the mass budget of the Shirase drainage basin (SHI), Antarctica, by separately estimating snow accumulation (surface mass balance; SMB) and glacier ice mass discharge (IMD). We estimated the SMB in the SHI, using a regional atmospheric climate model (RACMO2.1). The SMB of the mainstream A flow region was 12.1 ± 1.5 Gt a−1 for an area of 1.985 × 105 km2. Obvious overestimation of the model round the coast, ∼0.5 Gt a−1, was corrected for. For calculating the IMD, we employed a 15-m resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) with a digital elevation model (DEM) to determine the heights at the grounding line (GL), after comparison with the interpolated Bamber DEM grid heights; the results of this are referred to as the measured heights. Ice thickness data at the GL were inferred by using a free-board relationship between the measured height and the ice thickness, and considering the measured firn depth correction (4.2 m with the reference ice density of 910 kg m−3) for the nearby blue-ice area. The total IMD was estimated to be 14.0 ± 1.8 Gt a−1. Semi-empirical firn densification model gives the estimate within 0.1–0.2 Gt a−1 difference. The estimated net mass balance, –1.9 Gt a−1, has a two-σ uncertainty of ±3.3 Gt a−1, and probable melt water discharge strongly suggests negative NMB, although the associated uncertainty is large.