A 40-year accumulation dataset for Adelie Land, Antarctica and its application for model validation
The GLACIOCLIM-SAMBA (GS) Antarctic accumulation monitoring network, which extends from 28 the coast of Adelie Land to the Antarctic plateau, has been surveyed annually since 2004. The network includes a 156-km stake-line from the coast inland, along which accumulation shows high spatial and 30 interannual variability with a mean value of 362 mm water equivalent a-1. In this paper, this
accumulation is compared with older accumulation reports from between 1971 and 1991. The mean 32 and annual standard deviation and the km-scale spatial pattern of accumulation were seen to be very similar in the older and more recent data. The data did not reveal any significant accumulation trend 34 over the last 40 years. The ECMWF analysis-based forecasts (ERA-40 and ERA-Interim), a stretchedgrid
global general circulation model (LMDZ4) and three regional circulation models (PMM5, MAR 36 and RACMO2), all with high resolution over Antarctica (27-125 km), were tested against the GS reports. They qualitatively reproduced the meso-scale spatial pattern of the annual-mean accumulation
38 except MAR. MAR significantly underestimated mean accumulation, while LMDZ4 and RACMO2 overestimated it. ERA-40 and the regional models that use ERA-40 as lateral boundary condition 40 qualitatively reproduced the chronology of interannual variability but underestimated the magnitude of interannual variations. Two widely used climatologies for Antarctic accumulation agreed well with the 42 mean GS data. The model-based climatology was also able to reproduce the observed spatial pattern.
These data thus provide new stringent constraints on models and other large-scale evaluations of the
44 Antarctic accumulation.
Authors: Agosta, C., Favier, V., Genthon, C., Gallée, H., Krinner, G., Lenaerts, J.T.M., van de Broeke, M.R.