This research was funded by NSERC and CFCAS in support of the Canadian CLIVAR Research Network. We are grateful to Dr. Hai Lin for originally pointing out the discrepancy between the trend in the NCEP–NCAR and ERA-40 reanalyses over Asia, and to Dr. Jian Lu for his help in the early stages of this work. Comments from Simon Blessing, Dr. Holger Pohlmann, and two anonymous reviewers are also much appreciated.
Bader, J., and M. Latif, 2003: The impact of decadal-scale Indian Ocean sea surface temperature anomalies on Sahelian rainfall and the North Atlantic Oscillation. Geophys. Res. Lett, 30 .2169, doi:10.1029/2003GL018426.
Barnston, A. G., and R. E. Livezey, 1987: Classification, seasonality and persistence of low-frequency atmospheric circulation patterns. Mon. Wea. Rev, 115 , 1083–1126.
Beniston, M., 2004: The 2003 heat wave in Europe: A shape of things to come? Geophys. Res. Lett, 31 .L02202, doi:10.1029/2003GL018857.
Chelliah, M., and C. F. Ropelewski, 2000: Reanalyses-based tropospheric temperature estimates: Uncertainties in the context of global climate change detection. J. Climate, 13 , 3187–3205.
Chelliah, M., and G. D. Bell, 2004: Tropical multidecadal and interannual climate variability in the NCEP–NCAR reanalysis. J. Climate, 17 , 1777–1803.
Folland, C. K., T. N. Palmer, and D. E. Parker, 1986: Sahel rainfall and worldwide sea temperatures, 1901–85. Nature, 320 , 602–607.
Giannini, A., R. Saravanan, and P. Chang, 2003: Oceanic forcing of Sahel rainfall on interannual to interdecadal time scales. Science, 302 , 1027–1030.
Hurrell, J. W., and C. K. Folland, 2002: A change in the summer atmospheric circulation over the North Atlantic. CLIVAR Exchanges, Vol. 7, No. 3/4, International CLIVAR Project Office, Southampton, United Kingdom, 52–54.
Hurrell, J. W., Y. Kushnir, G. Ottersen, and M. Visbeck, 2003: An overview of the North Atlantic Oscillation. The North Atlantic Oscillation, Geophys. Monogr., Vol. 134, Amer. Geophys. Union, 1–35.
Inoue, T., and J. Matsumoto, 2004: A comparison of summer sea level pressure over east Eurasia between NCEP–NCAR reanalysis and ERA-40 for the period 1960–99. J. Meteor. Soc. Japan, 82 , 951–958.
Kistler, R., and Coauthors, 2001: The NCEP–NCAR 50-Year Reanalysis: Monthly means CD-ROM and documentation. Bull. Amer. Meteor. Soc, 82 , 247–268.
Lu, J., R. J. Greatbatch, and K. A. Peterson, 2004: On the trend in Northern Hemisphere winter atmospheric circulation during the last half of the twentieth century. J. Climate, 17 , 3745–3760.
Pal, J. S., F. Giorgi, and X. Q. Bi, 2004: Consistency of recent European summer precipitation trends and extremes with future regional climate projections. Geophys. Res. Lett, 31 .L13202, doi:10.1029/2004GL019836.
Parker, D. E., T. P. Legg, and C. K. Folland, 1992: A new daily central England temperature series, 1772–1991. Int. J. Climatol, 12 , 317–342.
Rodwell, M. J., and C. K. Folland, 2002: Atlantic air-sea interaction and seasonal predictability. Quart. J. Roy. Meteor. Soc, 128 , 1413–1443.
Sturaro, G., 2003: A closer look at the climatological discontinuities present in the NCEP–NCAR reanalysis temperature due to the introduction of satellite data. Climate Dyn, 21 , 309–316.
Trenberth, K. E., and D. A. Paolino Jr., 1980: The Northern Hemisphere sea-level pressure data set: Trends, errors and discontinuities. Mon. Wea. Rev, 108 , 855–872.
Ward, M. N., 1998: Diagnosis and short-lead time prediction of summer rainfall in tropical North Africa at interannual and multidecadal timescales. J. Climate, 11 , 3167–3191.
Yang, S., K-M. Lau, and K-M. Kim, 2002: Variations of the East Asian jet stream and Asian–Pacific–American winter climate anomalies. J. Climate, 15 , 306–325.