Abstract
High-spatial resolution surface mass balance (SMB) over the West Antarctic Ice Sheet (WAIS) spanning 1800–2010 is reconstructed by means of ice core records combined with the outputs of the European Centre for Medium-Range Weather Forecasts “Interim” reanalysis (ERA-Interim) and the latest polar version of the Regional Atmospheric Climate Model (RACMO2.3p2). The reconstruction reveals a significant negative trend (−1.9 ± 2.2 Gt/year·per decade) in the SMB over the entire WAIS during the nineteenth century, but a statistically significant positive trend of 5.4 ± 2.9 Gt/year·per decade between 1900 and 2010, in contrast to insignificant WAIS SMB changes during the twentieth century reported earlier. At regional scales, the Antarctic Peninsula and western WAIS show opposite SMB trends, with different signs in the nineteenth and twentieth centuries. The annual resolution reconstruction allows us to examine the relationships between SMB and large-scale atmospheric oscillations. Although SMB over the Antarctic Peninsula and western WAIS correlates significantly with the Southern Annular Mode due to the influence of the Amundsen Sea Low, and El Niño/Southern Oscillation during 1800–2010, the significant correlations are temporally unstable, associated with the phase of Southern Annular Mode, El Niño/Southern Oscillation and the Pacific decadal oscillation. In addition, the two climate modes seem to contribute little to variability in SMB over the whole WAIS on decadal-centennial time scales. This new reconstruction also serves to identify unreliable precipitation trends in ERA-Interim and thus has potential for assessing the skill of other reanalyses or climate models to capture precipitation trends and variability.
| Original language | English |
|---|---|
| Pages (from-to) | 5282-5295 |
| Number of pages | 14 |
| Journal | Journal of Geophysical Research: Atmospheres |
| Volume | 124 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - 27 May 2019 |
Funding
This work was funded by the Strategic Priority Research Program of the Chinese Academy of Sciences (XAD19070103), the Outstanding Youth Fund of Shandong Provincial Universities (ZR2016JL030), and the National Natural Science Foundation of China (41576182). M. R. van den Broeke and J. M. van Wessem acknowledge support from the Netherlands Polar Program and the Netherlands Earth System Science Center (NESSC). Snow accumulation data is a contribution to the PAGES 2k Network through the Antarctica 2k and CLIVASH2k projects. Past Global Changes (PAGES) is funded by the U.S. National Science Foundation and the Swiss Academy of Sciences. Thanks to the three anonymous reviewers for their constructive and thoughtful comments and advice to improve this paper. ERA-Interim data are obtained from ECMWF data server (http://apps.ecmwf.int/datasets/). HadSLP2 data are provided by Met Office Hadley Centre observations datasets (http://www.metoffice.gov.uk/hadobs/hadslp2/). SAM index developed by Abram et al. () comes from ftp://ftp.ncdc.noaa.gov/pub/data/paleo/contributions_by_author/abram2014/abram2014sam.txt. SOI developed by Allan et al. () is available at http://www.cru.uea.ac.uk/cru/data/soi/. Ice core snow accumulation data are available at https://doi.org/10.5285/c4ecfe25-12f2-453b-ad19-49a19e90ee32. PDO data are hosted at http://research.jisao.washington.edu/data/pdo/ website. RACMO2.3p2 accumulation fields can be obtained from M. R. van de Broeke and J. M. van Wessem without conditions. Snow accumulation data reconstructed by Medley and Thomas () come from the NASA Goddard Cryosphere data portal (https://neptune.gsfc.nasa.gov/csb/). Our reconstructed WAIS SMB data are available at http://poles.tpdc.ac.cn/ website.
