%0 Journal Article %1 Biasutti2008SST %A Biasutti, M. %A Held, I. M. %A Sobel, A. H. %A Giannini, A. %B Journal of Climate %D 2008 %I American Meteorological Society %J J. Climate %K llr %N 14 %P 3471--3486 %R 10.1175/2007jcli1896.1 %T SST Forcings and Sahel Rainfall Variability in Simulations of the Twentieth and Twenty-First Centuries %U http://dx.doi.org/10.1175/2007jcli1896.1 %V 21 %X Abstract The outlook for Sahel precipitation in coupled simulations of the twenty-first century is very uncertain, with different models disagreeing even on the sign of the trends. Such disagreement is especially surprising in light of the robust response of the same coupled models to the twentieth-century forcings. This study presents a statistical analysis of the preindustrial, twentieth-century and twenty-first-century A1B scenario simulations in the latest Coupled Model Intercomparison Project 3 (CMIP3) dataset; it shows that the relationship that links Sahel rainfall anomalies to tropical sea surface temperature (SST) anomalies at interannual time scales in observations is reproduced by most models, independently of the change in the basic state as the world warms. The same SST?Sahel relationship can be used to predict the simulated twentieth-century changes in Sahel rainfall from each model?s simulation of changes in Indo-Pacific SST and Atlantic SST meridional gradient, although the prediction overestimates the simulated trends. Conversely, such a relationship does not explain the rainfall trend in the twenty-first century in a majority of models. These results are consistent with there being, in most models, a substantial direct positive effect of atmospheric greenhouse gases on Sahel rainfall, not mediated through SST.

@article{Biasutti2008SST, abstract = {Abstract The outlook for Sahel precipitation in coupled simulations of the twenty-first century is very uncertain, with different models disagreeing even on the sign of the trends. Such disagreement is especially surprising in light of the robust response of the same coupled models to the twentieth-century forcings. This study presents a statistical analysis of the preindustrial, twentieth-century and twenty-first-century {A1B} scenario simulations in the latest Coupled Model Intercomparison Project 3 ({CMIP3}) dataset; it shows that the relationship that links Sahel rainfall anomalies to tropical sea surface temperature ({SST}) anomalies at interannual time scales in observations is reproduced by most models, independently of the change in the basic state as the world warms. The same {SST}?Sahel relationship can be used to predict the simulated twentieth-century changes in Sahel rainfall from each model?s simulation of changes in {Indo-Pacific} {SST} and Atlantic {SST} meridional gradient, although the prediction overestimates the simulated trends. Conversely, such a relationship does not explain the rainfall trend in the twenty-first century in a majority of models. These results are consistent with there being, in most models, a substantial direct positive effect of atmospheric greenhouse gases on Sahel rainfall, not mediated through {SST}.}, added-at = {2019-08-14T18:35:35.000+0200}, author = {Biasutti, M. and Held, I. M. and Sobel, A. H. and Giannini, A.}, biburl = {https://www.bibsonomy.org/bibtex/298ccd0d131375a2db6bd5d7da97adc87/karinawilliams}, booktitle = {Journal of Climate}, citeulike-article-id = {3064865}, citeulike-linkout-0 = {http://journals.ametsoc.org/doi/abs/10.1175/2007JCLI1896.1}, citeulike-linkout-1 = {http://dx.doi.org/10.1175/2007jcli1896.1}, comment = {(private-note)"Another important conclusion that arises from this analysis is that a faithful reproduction of the twentieth century is not in itself assurance that any given model will be accurate in its prediction of the future. More specifically, the fact that two models both dry the Sahel in the twentieth century and do so through the same influence of SST anomalies does not mean that they will behave similarly in a simulation of the future. Therefore, similarity to observations in a simulation of the twentieth-century climate appears to be a necessary but insufficient condition for a trustworthy prediction of the future." doesn't appear in bibliography of final draft of Carlo's book chapter}, day = 1, doi = {10.1175/2007jcli1896.1}, interhash = {f92b54ba303cfb7c9385fae73799904c}, intrahash = {98ccd0d131375a2db6bd5d7da97adc87}, journal = {J. Climate}, keywords = {llr}, month = jul, number = 14, pages = {3471--3486}, posted-at = {2011-12-21 15:42:53}, priority = {2}, publisher = {American Meteorological Society}, timestamp = {2019-08-14T18:35:35.000+0200}, title = {{SST} Forcings and Sahel Rainfall Variability in Simulations of the Twentieth and {Twenty-First} Centuries}, url = {http://dx.doi.org/10.1175/2007jcli1896.1}, volume = 21, year = 2008 }