There is a new paper that makes an important finding regarding the causes of the 2010 Russian heat wave (h/t to Attribution and the Russian heat wave).
The paper is
Dole, R., M. Hoerling, J. Perlwitz, J. Eischeid, P. Pegion, T. Zhang, X.-W. Quan, and D. Murray (2011), Was there a basis for anticipating the 2010 Russian heat wave? Geophys. Res. Lett., doi:10.1029/2010GL046582, in press.
The abstract reads [highlight added]
“The 2010 summer heat wave in western Russia was extraordinary, with the region experiencing the warmest July since at least 1880 and numerous locations setting all-time maximum temperature records. This study explores whether early warning could have been provided through knowledge of natural and human-caused climate forcings. Model simulations and observational data are used to determine the impact of observed sea surface temperatures (SSTs), sea ice conditions and greenhouse gas concentrations. Analysis of forced model simulations indicates that neither human influences nor other slowly evolving ocean boundary conditions contributed substantially to the magnitude of this heat wave. They also provide evidence that such an intense event could be produced through natural variability alone. Analysis of observations indicate that this heat wave was mainly due to internal atmospheric dynamical processes that produced and maintained a strong and long-lived blocking event, and that similar atmospheric patterns have occurred with prior heat waves in this region. We conclude that the intense 2010 Russian heat wave was mainly due to natural internal atmospheric variability. Slowly varying boundary conditions that could have provided predictability and the potential for early warning did not appear to play an appreciable role in this event.”
In their conclusions they write
“Our analysis points to a primarily natural cause for the Russian heat wave. This event appears to be mainly due to internal atmospheric dynamical processes that produced and maintained an intense and long-lived blocking event. Results from prior studies suggest that it is likely that the intensity of the heat wave was further increased by regional land surface feedbacks. The absence of long-term trends in regional mean temperatures and variability together with the model results indicate that it is very unlikely that warming attributable to increasing greenhouse gas concentrations contributed substantially to the magnitude of this heat wave.”
This finding is agrees with what we and others concluded regarding the European heat wave of 2003; i.e.
Chase, T.N., K. Wolter, R.A. Pielke Sr., and Ichtiaque Rasool, 2006: Was the 2003 European summer heat wave unusual in a global context? Geophys. Res. Lett., 33, L23709, doi:10.1029/2006GL027470
Chase, T.N., K. Wolter, R.A. Pielke Sr., and Ichtiaque Rasool, 2008: Reply to comment by W.M. Connolley on ‘‘Was the 2003 European summer heat wave unusual in a global context?’’Geophys. Res. Lett., 35, L02704, doi:10.1029/2007GL031574
Connolley W.M. 2008: Comment on “Was the 2003 European summer heat wave unusual in a global context?” by Thomas N. Chase et al. Geophys. Res. Lett., 35, L02703, doi:10.1029/2007GL031171.
In our 2008 paper we wrote
“Therefore we also conclude that land surface conditions (low soil moisture) are the likely direct cause for such an ‘‘unusual’’ event near the surface. This is supported by Fischer et al.  who reported the lack of rainfall the preceding spring as an important contributing factor in enhancing the 2003 heat wave.”
The role of land surface conditions in droughts is further supported by the results reported in Dole et al 2011.
The next text in their conclusion, however, is where they make the mistake of assuming the IPCC multi-decadal global climate models can skillfully predict climate through the rest of the 21st century. They write
“Nevertheless, there is evidence that such warming has contributed to observed heat waves in other regions, and is very likely to produce more frequent and extreme heat waves later this century [Intergovernmental Panel on Climate Change, 2007]. To assess this possibility for the region of western Russia, we have used the same IPCC model simulations to estimate the probability of exceeding various July temperature thresholds over the period 1880-2100 (Figure 4). The results suggest that we may be on the cusp of a period in which the probability of such events increases rapidly, due primarily to the influence of projected increases in greenhouse gas concentrations.”
This part of their otherwise excellent study is misleading as there is no skill at predicting droughts (including their statistical frequency) decades from now. Papers such as
Stephens, G. L., T. L’Ecuyer, R. Forbes, A. Gettlemen, J.‐C. Golaz, A. Bodas‐Salcedo, K. Suzuki, P. Gabriel, and J. Haynes (2010), Dreary state of precipitation in global models, J. Geophys. Res., 115, D24211, doi:10.1029/2010JD014532.
should be sufficient to show that the reporting in Dole et al 2011 of IPCC multi-decadal model simulations as robust science is flawed and misleading.