The 20th century displayed a rich spectrum of climate variations, including El Niño and the Southern Oscillation (ENSO), monsoon floods and droughts, sub-Saharan drought, substantial variations in the character of the Arctic Oscillation, the North Atlantic Oscillation (both winter and summer), the Pacific Decadal Oscillation, the North American Dust Bowl, changes in the Antarctic Oscillation etc. These climate variations may be the result of atmospheric (internal) modes or coupled ocean-atmosphere modes or they may be related to anthropogenic forcing associated with emission of greenhouse gases and aerosols and land use change. The International Climate of the Twentieth Century (C20C; Folland et al. 2002) project was conceived to address this question by imposing the observed atmospheric forcing functions of the last 150 years or so on state-of- the-art atmospheric general circulation models (AGCMs) and coupled global climate models (CGCM) to determine primarily the extent to which these seasonal to interdecadal variations are reproducible. It also contributes to the AMIP and CMIP type experiments, as appropriate. C20C was originally created by the UK Met Office Hadley Centre in 1993 to feed into the Climate Models - Evaluation chapter of the Second Report of the Intergovernmental Panel on Climate Change (1996). Re-launched by COLA and the Met Office Hadley Centre in 2000, it became a CLIVAR project in 2003.
Many papers have been inspired by, or created directly under the auspices of, C20C; a list is maintained on the C20C web site http://portal.nersc.gov/c20c/pub.html. Fairly recently a set of four coordinated papers were published in Climate Dynamics (Grainger et al., 2011; Kucharski et al. 2009; Scaife et al. 2009; and Zhou et al. 2009). Because C20C, like AMIP, prominently includes the use of AGCMs, this has lead to several studies of the relative merits of CGCMs and AGCMs for climate variability and trend research (e.g. Chen et al. 2013).
The key core projects of C20C are discussed in Kinter and Folland (2011). The 6th Workshop of the C20C project will take place on 5-8 November 2013 in Melbourne, Australia, where a new core project will be discussed on research into Operational Detection and attribution to be carried out collaboratively with the ad hoc International Detection and Attribution Group.
- Chen, H, E. K. Schneider, B.P Kirtman and I. Colfescu, 2013: Evaluation of Weather Noise and Its Role in Climate Model Simulations. J. Climate, 26, 3766-3784.
- Folland, C., J. Shukla, J. Kinter, and M. Rodwell, 2002: The Climate of the Twentieth Century Project. CLIVAR Exchanges, June 2002, 3 pp.
- Grainger, S., C. S. Frederiksen, X. Zheng, D. Fereday, C.K. Folland, E. K. Jin, J. L. Kinter, J. R. Knight, S. Schubert and J. Syktus, 2011: Modes of variability of Southern Hemisphere atmospheric circulation estimated by AGCMs. Clim. Dyn. 36, 473-490 doi: 10.1007/s00382-009-0720-7.
- Kinter, J. and C.K Folland, 2011: The International CLIVAR Climate of the 20th Century Project: Report of the Fifth Workshop. CLIVAR Exchanges, 57, 39-42.
- Kucharski, F., A. A. Scaife, J. H. Yoo, C. K. Folland, J. L. Kinter, A. Fereday, A. Fischer, E. K. Jin, M.-J. Nath, P. Pegion, P. V. Sporyshev, A. Voldoire, J. H. Yoon, T. Zhou and S. Schubert, 2009: The CLIVAR C20C Project: Part 2: Skill of simulating Indian monsoon rainfall on interannual to decadal timescales. Does GHG forcing play a role? Clim. Dyn.33, 615-627.doi: 10.1007/s00382-008-0462-y.
- Scaife, A. A., F. Kucharski, C. K. Folland, J. Kinter, D. Fereday, S. Grainger, E. K. Jin, J. R. Knight, S. Kusunoki, M.-J. Nath, T. Nakaegawa, P. Pegion, S. Schubert, P. Sporyshev, J. Syktus, A. Voldoire, J. H.Yoon and T. Zhou, 2009: The CLIVAR C20C Project. Part 1: Selected 20th century changes. Clim. Dyn. 33, 603-614 DOI 10.1007/s00382-008-0451-1
- Zhou, T., B. Wu, A. A. Scaife, L. Li, A. Fischer, A. Voldoire, B. Wang, C. K. Folland, D. Fereday, F. Kucharski J. L. Kinter, K. E. Jin, M.-J. Nath, N-C.Lau, P. Pegion, S. Kusunoki, T. Nakaegawa, and J. Syktus, 2009: The CLIVAR C20C Project: which components of the Asian-Australian Monsoon variability are forced and reproducible? Clim. Dyn. 33, 1051-1068. 10.1007/s00382-008-0501-8