Present‐Day and Future Antarctic Ice Sheet Climate and Surface Mass Balance in the Community Earth System Model

TitlePresent‐Day and Future Antarctic Ice Sheet Climate and Surface Mass Balance in the Community Earth System Model
Publication TypeJournal Article
Year of Publication2016
AuthorsFyke, Jeremy Garmeson
JournalClimate Dynamics
Volume47
Number5 - 6
Pages1,367 - 1,381
Date Published09/2016
Abstract / Summary

We present climate and surface mass balance (SMB) of the Antarctic ice sheet (AIS) as simulated by the global, coupled ocean–atmosphere–land Community Earth System Model (CESM) with a horizontal resolu- tion of ∼1 degrees in the past, present and future (1850–2100). CESM correctly simulates present-day Antarctic sea ice extent, large-scale atmospheric circulation and near-surface climate, but fails to simulate the recent expansion of Antarctic sea ice. The present-day Antarctic ice sheet SMB equals 2280 ± 131 Gt year−1, which concurs with existing independent estimates of AIS SMB. When forced by two CMIP5 climate change scenarios (high mitigation scenario RCP2.6 and high-emission scenario RCP8.5), CESM projects an increase of Antarctic ice sheet SMB of about 70 Gt year−1 per degree warming. This increase is driven by enhanced snowfall, which is partially counteracted by more surface melt and runoff along the ice sheet’s edges. This intensifying hydrological cycle is predominantly driven by atmospheric warming, which increases (1) the moisture-carrying capacity of the atmosphere, (2) oceanic source region evaporation, and (3) summer AIS cloud liquid water content. 

URLhttps://link.springer.com/article/10.1007/s00382-015-2907-4
DOI10.1007/s00382-015-2907-4
Journal: Climate Dynamics
Year of Publication: 2016
Volume: 47
Number: 5 - 6
Pages: 1,367 - 1,381
Date Published: 09/2016

We present climate and surface mass balance (SMB) of the Antarctic ice sheet (AIS) as simulated by the global, coupled ocean–atmosphere–land Community Earth System Model (CESM) with a horizontal resolu- tion of ∼1 degrees in the past, present and future (1850–2100). CESM correctly simulates present-day Antarctic sea ice extent, large-scale atmospheric circulation and near-surface climate, but fails to simulate the recent expansion of Antarctic sea ice. The present-day Antarctic ice sheet SMB equals 2280 ± 131 Gt year−1, which concurs with existing independent estimates of AIS SMB. When forced by two CMIP5 climate change scenarios (high mitigation scenario RCP2.6 and high-emission scenario RCP8.5), CESM projects an increase of Antarctic ice sheet SMB of about 70 Gt year−1 per degree warming. This increase is driven by enhanced snowfall, which is partially counteracted by more surface melt and runoff along the ice sheet’s edges. This intensifying hydrological cycle is predominantly driven by atmospheric warming, which increases (1) the moisture-carrying capacity of the atmosphere, (2) oceanic source region evaporation, and (3) summer AIS cloud liquid water content. 

DOI: 10.1007/s00382-015-2907-4
Citation:
Fyke, JG.  2016.  "Present‐Day and Future Antarctic Ice Sheet Climate and Surface Mass Balance in the Community Earth System Model."  Climate Dynamics 47(5 - 6): 1367 - 1381.  https://doi.org/10.1007/s00382-015-2907-4.