Description

Climate model projections of 21^st century change in surface air temperature (temperature 2m above the surface) by the end of the 21st century (2069-2098) following a range of low (RCP2.6) medium (RCP4.5) and high (RCP8.5) radiative forcing scenarios of known important climate drivers such as greenhouse gas increases and stratospheric ozone recovery. Each column shows a different season as follows: austral summer is defined as December-February; autumn is March-May; winter is June-August; and spring is September-November. Changes are all relative to the period 1970-1999 in ‘historical’ climate model simulations with observed levels of greenhouse gases and other known natural and anthropogenic factors. Contour intervals are 1 K. The climate model dataset used is the Coupled Model Intercomparison Project Phase 5 (CMIP5) dataset (Taylor et al., 2012).

The projection data from the multiple different climate models was combined using the method detailed in Bracegirdle and Stephenson (2012). This provides more precise and robust projections of Antarctic climate change by accounting for biases associated with sea ice. The observationally-constrained dataset used calibrate the projections is ERA-Interim (Dee et al., 2011). Different numbers of CMIP5 models were available for different scenarios and are listed below.

Strengths and weaknesses

Strengths:

• Provides a quick summary of the broad changes projected across Antarctica estimated from a wide range of CMIP5 models.
• Improves on a simple all-model average by taking account of regional biases associated with sea ice (see Bracegirdle and Stephenson (2012) for more details).

Weaknesses and caveats:

• The global climate models used do not fully resolve the steep and complex mountains around large parts of coastal Antarctica the Antarctic Peninsula
• The differences between scenarios could in part be due to the differing subsets of models available from each RCP experiment
• The method of Bracegirdle and Stephenson (2012) should be viewed as a starting point and AntClim21 are currently working towards a broader community-agreed evaluation of climate model projections that will provide further improvements by taking into account a wider range of factors in model performance

Any questions on these maps or requests for further information should be addressed to Tom Bracegirdle (This email address is being protected from spambots. You need JavaScript enabled to view it.).

References

• Bracegirdle, T. J., and D. B. Stephenson (2012), Higher precision estimates of regional polar warming by ensemble regression of climate model projections, Clim. Dyn., 39(12), 2805-2821, doi: 10.1007/s00382-012-1330-3.
• Dee DP, et al. (2011) The ERA-Interim reanalysis: configuration and performance of the data assimilation system. Q J R Meteorol Soc 137(656):553–597. doi:10.1002/qj.828
• Taylor, K. E., R. J. Stouffer, and G. A. Meehl, 2012: An overview of CMIP5 and the experiment design. Bull. Amer. Meteor. Soc., 93, 485–498.
  
  

Acknowledgements

We acknowledge the World Climate Research Programme's Working Group on Coupled Modelling, which is responsible for CMIP, and we thank the climate modeling groups (listed in Table XX of this paper) for producing and making available their model output. For CMIP the U.S. Department of Energy's Program for Climate Model Diagnosis and Intercomparison provides coordinating support and led development of software infrastructure in partnership with the Global Organization for Earth System Science Portals. The European Centre for Medium Range Weather Forecasting is

thanked for providing the ERA-Interim datasets.

Models used

RCP2.6

'bcc-csm1-1','bcc-csm1-1-m','bnu-esm','canesm2','ccsm4','cesm1-cam5','cesm1-waccm','cnrm-cm5','csiro-mk3-6-0','ec-earth','fgoals-g2','fio-esm','gfdl-cm3','gfdl-esm2g','giss-e2-h','giss-e2-r','hadgem2-ao','hadgem2-es','ipsl-cm5a-lr','ipsl-cm5a-mr','miroc-esm-chem','miroc5','mpi-esm-lr','mpi-esm-mr','mri-cgcm3','noresm1-m','noresm1-me'

RCP4.5

'access1-0','access1-3','bcc-csm1-1','bcc-csm1-1-m','bnu-esm','canesm2','ccsm4','cesm1-bgc','cesm1-cam5','cesm1-waccm','cmcc-cm','cmcc-cms','cnrm-cm5','csiro-mk3-6-0','ec-earth','fgoals-g2','fio-esm','gfdl-cm3','gfdl-esm2g','gfdl-esm2m','giss-e2-h','giss-e2-h-cc','giss-e2-r','giss-e2-r-cc','hadgem2-ao','hadgem2-cc','hadgem2-es','inmcm4','ipsl-cm5a-lr','ipsl-cm5a-mr','ipsl-cm5b-lr','miroc-esm-chem','miroc5','mpi-esm-lr','mpi-esm-mr','mri-cgcm3','noresm1-m','noresm1-me'

RCP8.5

'access1-0','access1-3','bcc-csm1-1','bcc-csm1-1-m','bnu-esm','canesm2','ccsm4','cesm1-bgc','cesm1-cam5','cesm1-waccm','cmcc-cesm','cmcc-cm','cmcc-cms','cnrm-cm5','csiro-mk3-6-0','ec-earth','fgoals-g2','fio-esm','gfdl-cm3','gfdl-esm2g','gfdl-esm2m','giss-e2-h','giss-e2-h-cc','giss-e2-r','giss-e2-r-cc','hadgem2-ao','hadgem2-cc','hadgem2-es','inmcm4','ipsl-cm5a-lr','ipsl-cm5a-mr','ipsl-cm5b-lr','miroc-esm-chem','miroc5','mpi-esm-lr','mpi-esm-mr','mri-cgcm3','mri-esm1','noresm1-m','noresm1-me'