Changes in accumulated snowfall over the Antarctic Ice Sheet have an immediate and time-delayed impact on global mean sea level. The immediate impact is due to the instantaneous change in freshwater storage over the ice sheet, whereas the time-delayed impact acts in opposition through enhanced ice-dynamic flux into the ocean1. Here, we reconstruct 200 years of Antarctic-wide snow accumulation by synthesizing a newly compiled database of ice core records2 using reanalysis-derived spatial coherence patterns. The results reveal that increased snow accumulation mitigated twentieth-century sea-level rise by ~10 mm since 1901, with rates increasing from 1.1 mm decade−1 between 1901 and 2000 to 2.5 mm decade−1 after 1979. Reconstructed accumulation trends are highly variable in both sign and magnitude at the regional scale, and linked to the trend towards a positive Southern Annular Mode since 19573. Because the observed Southern Annular Mode trend is accompanied by a decrease in Antarctic Ice Sheet accumulation, changes in the strength and location of the circumpolar westerlies cannot explain the reconstructed increase, which may instead be related to stratospheric ozone depletion4. However, our results indicate that a warming atmosphere cannot be excluded as a dominant force in the underlying increase.
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The code for generating the reconstructions is available from the NASA Goddard Cryosphere data portal (https://neptune.gsfc.nasa.gov/csb/).
The snow accumulation reconstructions generated and analysed during this study are available from the NASA Goddard Cryosphere data portal (https://neptune.gsfc.nasa.gov/csb/). The reanalysis data are available as follows: CFSR (https://rda.ucar.edu/pub/cfsr.html), ERA-Interim (https://www.ecmwf.int/en/forecasts/datasets/archive-datasets/reanalysis-datasets/era-interim) and MERRA-2 (https://disc.gsfc.nasa.gov/). The ice core records are hosted at https://ramadda.data.bas.ac.uk/repository/entry/show?entryid=83f2ca40-04b5-4029-a04c-c18b202dc2f8.
Winkelmann, R., Levermann, A., Martin, M. A. & Frieler, K. Increased future ice discharge from Antarctica owing to higher snowfall. Nature 492, 239–242 (2012).
Thomas, E. R. et al. Review of regional Antarctic snow accumulation over the past 1000 years. Clim. Past Discuss. 2017, 1–42 (2017).
Marshall, G. J. Trends in the Southern Annular Mode from observations and reanalyses. J. Clim. 16, 4134–4143 (2003).
Lenaerts, J. T. M., Fyke, J. & Medley, B. The signature of ozone depletion in recent Antarctic precipitation change: a study with the Community Earth System Model. Geophys. Res. Lett. https://doi.org/10.1029/2018GL078608 (2018).
Beckley, B. et al. Assessment of the Jason-2 extension to the TOPEX/Poseidon, Jason-1 sea-surface height time series for global mean sea level monitoring. Mar. Geod. 33, 447–471 (2010).
Shepherd, A. et al. A reconciled estimate of ice-sheet mass balance. Science 338, 1183–1189 (2012).
Pritchard, H. D., Arthern, R. J., Vaughan, D. G. & Edwards, L. A. Extensive dynamic thinning on the margins of the Greenland and Antarctic ice sheets. Nature 461, 971–975 (2009).
Palerme, C. et al. Evaluation of current and projected Antarctic precipitation in CMIP5 models. Clim. Dynam. 48, 225–239 (2017).
Steig, E. J. et al. Warming of the Antarctic ice-sheet surface since the 1957 International Geophysical Year. Nature 457, 459–462 (2009).
Nicolas, J. P. & Bromwich, D. H. New reconstruction of Antarctic near-surface temperatures: multidecadal trends and reliability of global reanalyses. J. Clim. 27, 8070–8093 (2014).
Monaghan, A. J. et al. Insignificant change in Antarctic snowfall since the International Geophysical Year. Science 313, 827–831 (2006).
Schneider, D. P. & Fogt, R. L. Artifacts in century‐length atmospheric and coupled reanalyses over Antarctica due to historical data availability. Geophys. Res. Lett. 45, 964–973 (2018).
McConnell, J. R., Mosley‐Thompson, E., Bromwich, D. H., Bales, R. C. & Kyne, J. D. Interannual variations of snow accumulation on the Greenland Ice Sheet (1985–1996): new observations versus model predictions. J. Geophys. Res. Atmos. 105, 4039–4046 (2000).
Van Wessem, J. M. et al. Modelling the climate and surface mass balance of polar ice sheets using RACMO2: part 2: Antarctica (1979–2016). Cryosphere 12, 1479–1498 (2018).
Bromwich, D. H., Nicolas, J. P. & Monaghan, A. J. An assessment of precipitation changes over Antarctica and the Southern Ocean since 1989 in contemporary global reanalyses. J. Clim. 24, 4189–4209 (2011).
Palerme, C. et al. Evaluation of Antarctic snowfall in global meteorological reanalyses. Atmos. Res. 190, 104–112 (2017).
Medley, B. et al. Airborne-radar and ice-core observations of annual snow accumulation over Thwaites Glacier, West Antarctica confirm the spatiotemporal variability of global and regional atmospheric models. Geophys. Res. Lett. 40, 3649–3654 (2013).
Medley, B. et al. Constraining the recent mass balance of Pine Island and Thwaites glaciers, West Antarctica, with airborne observations of snow accumulation. Cryosphere 8, 1375–1392 (2014).
Thompson, D. W. & Wallace, J. M. Annular modes in the extratropical circulation. Part I: month-to-month variability. J. Clim. 13, 1000–1016 (2000).
Arblaster, J. M. & Meehl, G. A. Contributions of external forcings to southern annular mode trends. J. Clim. 19, 2896–2905 (2006).
Van Den Broeke, M. R. & Van Lipzig, N. P. Changes in Antarctic temperature, wind and precipitation in response to the Antarctic Oscillation. Ann. Glaciol. 39, 119–126 (2004).
Fyke, J., Lenaerts, J. T. & Wang, H. Basin-scale heterogeneity in Antarctic precipitation and its impact on surface mass variability. Cryosphere 11, 2595–2609 (2017).
Stenni, B. et al. Antarctic climate variability on regional and continental scales over the last 2000 years. Clim. Past 13, 1609–1634 (2017).
Shepherd, A. et al. Mass balance of the Antarctic Ice Sheet from 1992 to 2017. Nature 556, 219–222 (2018).
Dee, D. P. et al. The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q. J. R. Meteorol. Soc. 137, 553–597 (2011).
Gelaro, R. et al. The Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2). J. Clim. 30, 5419–5454 (2017).
Saha, S. et al. The NCEP Climate Forecast System Reanalysis. Bull. Am. Meteorol. Soc. 91, 1015–1057 (2010).
Medley, B. et al. Temperature and snowfall in western Queen Maud Land increasing faster than climate model projections. Geophys. Res. Lett. 45, 1472–1480 (2018).
Favier, V. et al. An updated and quality controlled surface mass balance dataset for Antarctica. Cryosphere 7, 583–597 (2013).
Zwally, H. J., Giovinetto, M. B., Beckley, M. A. & Saba, J. L. Antarctic and Greenland Drainage Systems (GSFC Cryospheric Sciences Laboratory, 2012).
Haran, T., Bohlander, J., Scambos, T., Painter, T. & Fahnestock, M. MODIS Mosaic of Antarctica 2008–2009 (MOA2009) Image Map Version 1 (National Snow and Ice Data Center, 2014); https://doi.org/10.7265/N5KP8037
Scambos, T. A., Haran, T. M., Fahnestock, M. A., Painter, T. H. & Bohlander, J. MODIS-based Mosaic of Antarctica (MOA) data sets: continent-wide surface morphology and snow grain size. Remote Sens. Environ. 111, 242–257 (2007).
Gong, D. & Wang, S. Definition of Antarctic Oscillation index. Geophys. Res. Lett. 26, 459–462 (1999).
We acknowledge everyone involved in the collection and analysis of the ice core records used in our reconstruction, as well as A. Barker and J. Lenaerts for manuscript comments. B.M. and E.R.T. were supported by NASA’s ICESat-2 Project Science Office and the British Antarctic Survey (Natural Environment Research Council), respectively.
The authors declare no competing interests.
Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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Medley, B., Thomas, E.R. Increased snowfall over the Antarctic Ice Sheet mitigated twentieth-century sea-level rise. Nature Clim Change 9, 34–39 (2019). https://doi.org/10.1038/s41558-018-0356-x
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