|Peru Coast. Image NASA|
Climate in the Southeast Pacific (SEP) near the coast of Peru and Chile, in the words of the authors, "is controlled by complex upper-ocean, marine boundary layer and land processes and their interactions," and they say that variations in this system have "significant impacts on global climate," citing Ma et al. (1996), Miller (1977), Gordon et al. (2000) and Xie (2004). However, they write that "it is well known that coupled atmosphere-ocean general circulation models tend to have systematic errors in the SEP region, including a warm bias in sea surface temperature and too little cloud cover," as demonstrated by Mechoso et al. (1995), Ma et al. (1996), Gordon et al. (2000), McAvaney et al. (2001), Kiehl and Gent (2004), Large and Danabasoglu (2006), Wittenberg et al. (2006) and Lin (2007). And even though these biases have what they call "important impacts" on the simulation of earth's radiation budget and climate sensitivity, they say that "it is still uncertain" whether a similar bias is evident in most state-of-the-art coupled general circulation models [CGCMs] and to what extent the sea surface temperature [SST] biases are model dependent."
What it means
With such yet-unresolved problems associated with nearly all of the CGCMs that were employed in the preparation of the IPCC's AR4 Report and that pertain to processes that are said to have important impacts on earth's climate sensitivity, it is no wonder that the projections of those models are greeted with a solid dose of skepticism by those who realize that it is the height of folly to use the output of such imperfect models as the reason for wanting to entirely restructure the way mankind acquires the energy that makes possible our current level of industrial and technological development.
Zheng, Y., Shinoda, T., Lin, J.-L. and Kiladis, G.N. 2011. Sea surface temperature biases under the stratus cloud deck in the Southeast Pacific Ocean in 19 IPCC AR4 coupled general circulation models. Journal of Climate 24: 4139-4164.
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