Access

Brief Communication Arising

Nature 455, E1-E2 (11 September 2008) | doi:10.1038/nature07256; Received 16 January 2008; Accepted 9 May 2008

There is a Letter (3 January 2008) associated with this document.

There is a Brief Communication Arising (11 September 2008) associated with this document.

Open Innovation Challenges

naturejobs

More science jobs
Post a job for free

Arctic tropospheric warming amplification?

Peter W. Thorne1

Top

Arising from: R. G. Graversen, T. Mauritsen, M. Tjernström, E. Källén & G. Svensson Nature 451, 53–56 (2008); Graversen et al. reply

Relative rates of temperature change between the troposphere and surface, and the mechanisms that produce these changes, have long been a contentious issue. Graversen et al.1, predicated upon the ERA-40 reanalysis2, report polar tropospheric amplification of surface warming and attempt to explain this finding dynamically. Here we show (1) that data from satellites3, 4 and weather balloons5 indicate that the ERA-40 trends are increasingly unrealistic polewards of 62° N; (2) that the two other reanalyses considered1 exhibit very different polar trends; and (3) that the vertical profile of polar trends in ERA-40 is unrealistic, particularly above the troposphere. These quasi-independent strands of evidence imply that the pattern of warming in the Arctic troposphere is highly unlikely to be as given in ERA-40 and as reported by Graversen et al.1.