An updated and quality controlled surface mass balance dataset for Antarctica

Abstract

Abstract. We present an updated and quality controlled surface mass balance (SMB) database for the Antarctic ice sheet. Importantly, the database includes formatted metadata, such as measurement technique, elevation, time covered, etc, which allows any user to filter out the data. Here, we discard data with limited spatial and temporal representativeness, too small measurement accuracy, or lack of quality control. Applied to the database, this filtering process gives four times more reliable data than when applied to previously available databases. New data with high spatial resolution are now available over long traverses, and at low elevation in some areas. However, the quality control led to a considerable reduction in the spatial density of data in several regions, particularly over West Antarctica. Over interior plateaus, where the SMB is low, the spatial density of measurements remains high. This quality controlled dataset was compared to results from ERA-Interim reanalysis to assess whether field data allow us to reconstruct an accurate description of the main SMB distribution features in Antarctica. We identified large areas where data gaps impede model validation: except for very few areas (e.g., Adelie Land), measurements in the elevation range between 200 m and 1000 m above sea level are not regularly distributed and do not allow a thorough validation of models in such regions with complex topography, where the highest scattering of SMB values is reported. Clearly, increasing the spatial density of field measurements at low elevations, in the Antarctic Peninsula and in West Antarctica is a scientific priority.

Multi-year record of atmospheric mercury at Dumont d'Urville, East Antarctic coast: continental outflow and oceanic influences

“…10, Hg tot concentrations increased between 600-800 and 1000-1100 km from DC in areas characterized by steeper slopes and higher snow accumulation values. Several studies reported a gradual increase in snow accumulation from DC toward the coast (Magand et al, 2007;Verfaillie et al, 2012;Favier et al, 2013), in good agreement with a gradual increase in humidity (Bromwich et al, 2004). These results suggest that the wet deposition of Hg(II) species was enhanced near the coast, resulting in elevated Hg tot concentrations in surface snow samples.…”

Regional Antarctic snow accumulation over the past 1000 years

“…Ice core data used in this study. Data citations can be found in Table S1 and in Thomas (2017 Philippe et al (2016) building upon previous SMB compilation studies by Favier et al (2013) and Frezzotti et al (2013). Of the 79 records selected, 41 records extend over the past 200 years, and therefore this period has been selected as a focus for our reconstruction.…”

“…Mass losses from meltwater runoff are small in Antarctica, except for some parts of the Antarctic Peninsula. Multiple in situ SMB observations can be combined to produce an SMB map for selected ice sheet regions (Rotschky et al, 2007) or for the entire AIS (Favier et al, 2013). Alternatively, SMB can be simulated by (regional) atmospheric climate models, such as the Regional Atmospheric Climate Model (RACMO) version 2.3 (Van Wessem et al, 2014), and various reanalysis products such as ERA-Interim (Dee et al, 2001) or JRA55 (Kobayashi et al, 2015).…”

The modelled surface mass balance of the Antarctic Peninsula at 5.5 km horizontal resolution

“…ice cores, stake arrays and bomb horizons ( Fig. 1) (Turner et al, 2002;Favier et al, 2013;Scambos et al, 2014). Included in these data are five unpublished in situ observations from high elevations, obtained from a shallow ice core, sonic snow height measurements and camera observations of a snow stake over time (T. A.…”

“…Measuring AP SMB is a complicated task, as the high precipitation rates and the steep mountainous (and inaccessible) terrain leave large regions devoid of observational data; most observations are therefore located in relatively dry areas and/or over the flat ice shelves which are easily accessible (Favier et al, 2013). Ice and firn core observations have identified a doubling of accumulation over the WAP since 1850 (Thomas et al, 2008), an increase in AP SMB over the last 50 years (Peel, 1992), and a large spatial variability of the SMB (Turner et al, 2002).…”